Protemnodon mamkurra Kerr & Camens & Van Zoelen & Worthy & Prideaux 2024, sp. nov.
Creators: name: Kerr, Isaac A. R.
name: Camens, Aaron B.
name: Van Zoelen, Jacob D.
name: Worthy, Trevor H.
name: Prideaux, Gavin J.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Diprotodontia
Macropodidae
Protemnodon
Protemnodon mamkurra

description: Protemnodon mamkurra sp. nov.
LSID of new species: urn:lsid:zoobank.org: act: 1CD200A9-06C2-40FE-B789-AFE64466E2D5
Procoptodon pusio Owen; Owen (1876) pl. 31, figs 1–5. Not P. pusio Owen, 1874.
Procoptodon rapha Owen; Owen (1876) pl. 31, figs 6–9. Not P. rapha Owen, 1874.
Protemnodon anak Owen; Helgen et al. (2006), p. 303, appendix 2; Turney et al. (2008), p. 12152; Gillespie et al. (2012), p. 40, table 1, fig. 2,; Gillespie et al. (2015), p. 44, table 1; Llamas et al. (2015), p. 581; Cascini et al. (2019), p. 523. Not P. anak Owen, 1874.
Protemnodon brehus (Owen); Tedford (1967), pp. 97–109; Helgen et al. (2006), p. 303; Ayliffe et al. (2008), p. 1785.
Protemnodon roechus Owen; Helgen et al. (2006) p. 303, appendix 2.
Protemnodon sp. cf. P. roechus; Jankowski et al. (2016), p. 543.
Holotype: SAMA P59549 (field number FUCN 40 01) partial skeleton: partial LR maxillae, vertebrae T12, L2–4, Ca3 & Ca9?, nine partial ribs; LR humeri, L radius; LR partial pelvis, LR femur, L tibia & R proximal tibial epiphysis, L & partial R fibulae, L calcaneus, & R talus.
Type locality:
Green Waterhole Cave (=Fossil Cave, ASF code 5L81), 37°73'S, 140°5'E, Tantanoola, South Australia. A waterfilled karst sinkhole in limestone, located 25 km northwest of Mount Gambier in the Limestone Coast region of far southeastern South Australia (Baird 1985; Horne 1988).
The fossils in the type series of P. mamkurra sp. nov. were collected in 1979 and 1987–88 by teams from the South Australian Speleological Society Inc. led by Rod Wells (Horne 1988). The faunal composition and relative dating indicate a late Pleistocene age (125–15 ka) (Pledge 1980; Baird 1985; Newton 1988), and five U-series dates taken from cave rafts with no direct association with the P. mamkurra sp. nov. type material gave an age range of 61.5–59.1 ka (Mather et al. 2023).
Paratypes:
Green Waterhole Cave: SAMA P28613 semi-complete juvenile skeleton: R premaxilla fragment, L I1, partial splanchnocranium with maxillae, jugals & palate preserving dP2–M2, with P3 & M3 partially removed from crypt, partial neurocranium, complete mandible preserving i1a & dp2–m2, with m 3 in crypt, vertebrae C1–3 & C5–7, T 1, T 3, T 7 & T 12–14, S1–2, & Ca2–?12, eight partial ribs; LR partial scapulae, L humerus, proximal ulna & proximal radius; LR ilia, partial ischia & partial pubes (unfused), L femur & R distal femoral epiphysis, LR tibiae, LR calcanei, LR metatarsals IV; all postcranial epiphyses missing except distal femoral epiphyses. SAMA P27270 partial R maxilla.
Referred specimens:
Western Australia
Kudjal Yolgah Cave, Boranup: WAM 08.8.979 R humeral fragment; WAM 08.8.998 L humeral fragment; WAM 08.8.587 L metacarpals I–V; WAM 08.8.544 R humeral fragments, partial LR ulnae, radial fragment, and ischial fragment.
Tight Entrance Cave, Boranup: WAM 08.1.16 partial R ulna.
Leaena’s Breath Cave, Nullarbor: WAM 2020.6.301 R premaxilla fragment; WAM 2020.6.276 partial R maxilla; WAM 2020.6.291 partial juvenile R maxilla; WAM 2020.6.177 neurocranium fragment; WAM 2020.6.182 L I1 and juvenile R I1; WAM 2020.3.535 R DP3 and M1; WAM 2020.6.305 R dentary fragment; WAM 2020.3.221 axis vertebra; WAM 2020.6.384 ulna WAM 2020.3.591 L scaphoid; WAM 2020.6.72 metacarpal V and isolated metacarpal distal epiphysis; WAM 2020.3.211 metacarpal I; WAM 2020.6.199 metacarpal IV; WAM 2020.6.300 L distal manual phalanx? III; WAM 2020.6.281 proximal manual phalanx? III;; WAM 2020.6.377 R tibia; WAM 2020.6.379 L tibia; WAM 2020.6.87 distal tibia fragment; WAM 14.8.5 proximal pedal phalanx IV; WAM 2020.6.180 LR metatarsals V; WAM 2020.6.146 proximal and distal pedal phalanges IV; WAM 2020.6.123 distal pedal phalanx IV; WAM 2020.6.21 middle pedal phalanx V. Numerous unregistered specimens (field code ‘LBC’) stored in the Western Australian Museum, Perth.
Upper Chamber, Last Tree Cave, Nullarbor: WAM 02.7.11 partial LR dentaries, L I1 and i1; axis vertebra, thoracic, lumbar and caudal vertebrae and fragments, sacrum; partial L clavicle, and L humerus, ulnar fragments, triquetrum, scaphoid, capitatum, hamatum, trapezium, metacarpals II –V and 2x distal phalanges; partial L femur and femoral fragments, partial L tibia, partial LR talus, calcaneus and cuboid, L navicular and ectocuneiform, partial LR metatarsals IV and V, and L and partial R proximal, middle and distal pedal phalanges IV and V; WAM 05.4.71 I1, I3 and i1.
South Australia
Robertson Cave, Naracoorte: SAMA P59547 R dentary; SAMA P59546 R ulna, triquetrum, partial scaphoid, capitatum, hamatum, proximal manual phalanges I–V, middle phalanges II –V, distal phalanges III and V.
Main Fossil Chamber, Victoria Fossil Cave, Naracoorte: SAMA P20819 neurocranium; SAMA P59542 metacarpal III; SAMA P59540 L calcaneus; SAMA P59541 L metatarsal IV; SAMA P59543 juvenile LR metatarsals V.
New entrance, Victoria Fossil Cave: SAMA P20810 proximal manual phalanges II – IV, middle II – III and distal I–V, L calcaneus, R cuboid and metatarsal IV, LR metatarsals V, R proximal, middle and distal pedal phalanges IV and proximal and distal phalanges V.
Curramulka Town Well Cave, Yorke Peninsula: SAMA P59553 R maxilla, neurocranium, LR I1s, L M4, atlas vertebra and R scaphoid; SAMA P13027 partial cranium and mandible.
Queensland
Pearson’s Bed, King’s Creek, Darling Downs: IS V566 L premaxilla and maxillae.
Darling Downs (site unknown): NHMUK PVOR 35942c L metatarsal IV; NHMUK PVOR 35946 R metatarsal IV; NHMUK PVOR 35948 L metatarsal V.
New South Wales
Site 51, Lake Victoria: NMV P26570 LR femoral and tibial fragments, fibular fragment, partial R calcaneus, partial L metatarsals IV and V, and proximal pedal phalanx IV.
Cathedral Cave, Wellington: AM F161924 partial neurocranium.
Wellington Caves, Wellington (site unknown): AM F104747 partial juvenile R calcaneus.
Wombeyan Caves (site unknown): NMV P54901 partial neurocranium.
Victoria
Site 499, Bacchus Marsh: NMV P187473 partial splanchnocranium.
Hines Quarry, Bacchus Marsh: NMV P160365 & NMV P160366 partial splanchnocranium and partial L dentary (reassociated).
Tasmania
Scotchtown Cave, Smithton: QVM 2007 GFV 33 partial R metatarsal V.
Bone Aven (CP213), Mt Cripps: QVM 2000 GFV 10 & QVM 2001 GFV 11 partial juvenile cranium and R dentary(reassociated); QVM 2001 GFV 05, QVM 2000 GFV 13, QVM 2000 GFV 14, QVM 2001 GFV 57a/b, QVM 2001 GFV 57, QVM 2001 GFV 23 & QVM 2001 GFV 04 partial cranium R maxilla, two thoracic vertebrae (? T 13–14), two lumbar vertebrae (L3 and L5), partial R pelvis, L femur and R fibular fragment (reassociated); QVM 2001 GFV 06 partial juvenile L dentary; QVM 2001 GFV 01 R I1; QVM 2000 GFV 12 R i1; QVM 2001 GFV 03 R ilium; QVM 2001 GFV 02 partial L tibia; QVM 2001 GFV 02b juvenile L tibia; QVM 2001 GFV 08 L i1; QVM 2001 GFV 09 partial juvenile R maxilla; QVM 2001 GFV 10partial juvenile R dentary; QVM 2001 GFV 19 L M4; QVM 2001 GFV 39 partial juvenile R scapula; QVM 2001 GFV 40 partial juvenile LR femora; QVM 2001 GFV 58 two caudal vertebrae; QVM 2001 GFV 72 partial L radius; QVM 2002 GFV 08 LR premaxilla fragments; QVM 2002 GFV 21 partial juvenile L ulna; QVM 2002 GFV 07 caudal vertebra; QVM 2003 GFV 10 partial juvenile LR humeri; QVM 2003 GFV 12 partial ischium; QVM 2003 GFV 28 L fibular fragment.
Specific diagnosis:
Protemnodon mamkurra sp. nov. is distinguished from other species of Protemnodon by several unique osteological characteristics and by the combination of other dental and postcranial characteristics. The cranium of P. mamkurra sp. nov. is differentiated from all other members of the genus by possessing: a taller rostrum and broader, more curved, more ventromedially situated occipital condyles relative to the foramen magnum. The axial skeleton differs from all species of Protemnodon by having relatively broader, craniocaudally shorter axis vertebra and cervical vertebrae C3–7. The forelimb differs from all other species of Protemnodon in having: a more robust ulna and radius; and more dorsopalmarly flattened distal manual phalanges. The pes differs from all other species of Protemnodon in having: a calcaneus with large, craniocaudally level and semicontinuous lateral and medial talar facets and a sustentaculum tali with a pointed cranioplantar peak; a cuboid with a broader flexor groove; and distal phalanges IV and V with a V-shaped divot in the lateral and medial margins of the proximal surface.
The species is most similar in aspects of cranial morphology to P. viator sp. nov. The cranium is further distinguished from that of P. viator sp. nov. by having a more raised medial ridge on the basioccipital and in having the exoccipital less posteriorly curved over the foramen magnum. The dentary of P. mamkurra sp. nov. cannot be differentiated from those of P. viator sp. nov. and P. dawsonae sp. nov., and is otherwise most similar to that of P. anak, from which it differs in having a more dorsally deflected diastema and i1.
The teeth of P. mamkurra sp. nov. cannot be differentiated from those of P. viator sp. nov. The dentition of P. mamkurra sp. nov. is similar to that of P. dawsonae sp. nov. and P. anak, differing in possessing: a larger I1; uppers molars with a broader, lower and less distinct preparacrista; and in lacking a ventrolingual crest on the i1, instead exhibiting a thick, rounded ventrolingual enamel lip extending smoothly onto the lingual surface. It is further distinguished from P. dawsonae sp. nov. by having upper molars with no preprotocrista and an unkinked postparacrista. Differs further from P. anak in having: a relatively broader DP2 across the anterior cusp; DP3 lacking a distinct, raised preprotocrista (forelink) that forms half of an incomplete protoloph, instead having an absent or very slight preprotocrista and a complete protoloph; P3 with higher, more anteriorly extensive lingual crest that is smoothly curved in lingual view and lower, less distinct and less transversely aligned transverse ridgelets; upper molars with a lower postprotocrista and a stronger postparacrista; M1–M2 with a weaker preparacrista; broader p3 relative to length with fewer, less raised and less distinct ridgelets; and lower molars with a lower, less distinct cristid obliqua and more convex buccal lophid margins in posterior view.
The postcranial skeleton of P. mamkurra sp. nov. is most similar to that of P. dawsonae sp. nov. and P. viator sp. nov. The axial skeleton of P. mamkurra sp. nov. is further distinguished from that of P. dawsonae sp. nov. by its lumbar vertebrae with shallower transverse processes and centrum with relatively taller, slightly narrower cranial and caudal extremities, less concave ventrolateral surfaces, less concave ventral margin, and more raised ventral ridge. The hindlimb differs from that of P. dawsonae sp. nov. by having a pelvis with a larger caudal iliac spine, deeper gluteal fossa, less cranially tilted sacral surface, less laterally projected rectus tubercle, more deeply concave acetabulum and more convex and rugose caudal margin of dorsal part of ischium. The pes differs in having: larger, taller and relatively and absolutely broader calcaneus, with more bulbous lateral talar facet and caudal fibular facet, and fibular facets more plantarly extensive in lateral view; metatarsal IV with larger plantar cuboid facet; and metatarsal V with a less distally extensive lateral plantar tuberosity.
The axial skeleton of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in having: the atlas vertebra with lateral vertebral foramina that open laterally instead of caudally, and less caudally projected and extensive wings; taller cervical vertebrae C3–7 with less transversely aligned, more roof-like arches in cranial view, and a less caudoventrally projected caudal extremity of the centrum lacking a slightly bilobed ventral margin. The forelimb differs by its radius having a more distally situated cranial ridge. The manus is differentiated by: a scaphoid with the facets for the hamatum and capitatum less distinct from each other, and a thickened, raised dorsal ridge present on the dorsomedial margin of the radial facet; shorter and more robust metacarpals; and distal manual phalanges lacking a slight dorsal peak.
The hindlimb is differentiated from P. viator by: its pelvis having a taller rectus tubercle; a more gracile femur with a lower, less distinct intercondylar crest, a less medially projected lesser trochanter, weaker proximolateral ridge, relatively shorter lesser trochanteric ridge, broader and shallower trochlea, more rounded trochlear crests with relatively broader medial crest; and shorter, broader and much more robust tibia with more laterally curved cnemial crest in cranial view with less angular and distinct distal peak, and thicker proximal section of proximolateral crest. The pes is distinguished from that of P. viator sp. nov. by: its broader and more robust calcaneus, with a more rounded, less triangular calcaneal tuberosity in cross-section, larger and more bulbous talar facets, a larger and more bulbous fibular facet with a more rounded and caudally projected (rather than laterally projected) caudal component, and a more medially projected sustentaculum tali; a relatively broader cuboid with a less elongate, less plantarly projected lateral plantar tubercle, a less plantarly projected, slightly more medially situated medial plantar tubercle, a broader, less deeply concave flexor groove, and a broader metatarsal V facet; a broader navicular with a less plantarly extensive ectocuneiform facet; an ectocuneiform with a broader, more oval, and less plantarly extensive navicular facet, and a less deep plantar tubercle which is more rounded in medial view; a longer metatarsal IV with a larger plantar cuboid facet; a longer, less transversely compressed and dorsoplantarly shorter metatarsal V with a more dorsally situated and less plantomedially extensive cuboid facet; a proximal phalanx IV with a weaker waist; a more elongate middle phalanx IV; a distal phalanx IV with a more rounded dorsal peak; and a less transversely asymmetrical distal phalanx V.
Etymology:
Mamkurra (‘mahm-KUH-rah’) means ‘great kangaroo’ (mam is a prefix meaning ‘great’, kurra is ‘kangaroo’) in the Bungandidj language of the Boandik people of southeastern South Australia, on whose country the type locality is situated. The name was chosen by Boandik elders and language experts in cooperation with the authors.
Description and comparisons:
Cranium and dentition
Cranium (Fig. 37): Rostrum. Rostrum is tall to very tall, and is moderately to strongly ventrally deflected (Fig. 37a). Premaxilla is anteroventrally projected and narrows anteriorly; incisor-bearing part contributes ~50% of the ventral length from the anterior tip to the premaxilla-maxilla suture; lateral surface slightly concave, ventral surface quite planar; dorsal and lateral surfaces of the anterior part are pockmarked with very small foramina. Incisive foramen large and elongate, with a tapering channel extending anterolaterally from the foramen in ventral view, roughly toward I2. Anterior margin of the premaxilla slopes moderately dorsoposteriorly before curving sharply dorsally to the nasal suture; dorsoposterior component (‘walls’ of nasal cavity) is tall and smoothly convex; ventral premaxilla-maxilla suture is angled posterolaterally; lateral premaxilla-maxilla suture extends straight dorsally before curving smoothly posteriorly toward the posterior of the nasal. Nasal elongate, gently dorsally convex transversely, and projected anteriorly to shared medial point. Buccinator fossa smoothly concave, quite deep and tall, extends dorsally from the ventral margin of the corpus below the diastema to level with the dorsal extremity of the infraorbital foramen, and from immediately anterior to P3/DP2 across the premaxilla-maxilla suture; height and depth smoothly decrease anteriorly. Infraorbital foramen large, opening anteriorly, transversely compressed, positioned dorsal to P3/DP2. Maxillary foramen (posterior to infraorbital canal) large and rounded, with a shallow channel extending posteriorly from the opening along the posterior of the maxilla. Sphenopalatine foramen very small, with a narrow channel that extends posteriorly from it, broadening near the foramen rotundum. The foramen rotundum is large and oval. Frontal has a concave lateral surface, with greatest concavity at the midpoint of the temporal fossa; dorsolateral margin flares increasingly laterally (forming the supraorbital crest) over the anterior of the orbit with age; suture with the parietal is level with or posterior to the posterior margin of the temporal fossa.
Palatal region. Palatine quite broad, with the anterior part of the maxillo-palatine suture adjacent to the masseteric process in young individuals and migrating anteriorly with age to be level with the M1–2 boundary. Palatal fenestrae absent. Anterolateral palatine foramina elongate and situated adjacent to the anterolateral margins of the maxillo-palatine suture. Two small posterolateral foramina are adjacent to M4. Masseteric process large, broad, laterally projected, slightly posteriorly deflected, with ventral tip rotated laterally relative to the base. Mainly contributed by the maxilla, with the posterior component of the base contributed by the jugal. Increases in size, lateral projection and posterior deflection with age.
Lateral cranium. Lacrimal has two foramina on the anterodorsal margin of orbit; one is large, rounded, anteroventrally located, and abuts the midpoint of the anterior margin, the second is smaller and dorsoposteriorly located; both foramina with small crest bounding them dorsoposteriorly. Jugal increases in height posteriorly, before narrowing slightly posteriorly and bifurcating around the anterior tip of the zygomatic process of the squamosal into the postorbital process and an elongate posterior part; the dorsal margins of the suborbital jugal and the postorbital process are flattened and broad. A low, angular ridge extends from immediately posterior to the midpoint of the anterior margin of the jugal across the posterior part. Zygomatic process of the squamosal has a smoothly convex dorsal margin in lateral view, tilted medially to be slightly dorsal facing; lower and less tilted in juveniles. Ventral margin broadens posteriorly toward the glenoid fossa. Medial component of the squamosal is broadly convex and elongate; a low, angular ridge extends from the dorsoposterior base of the zygomatic process, borders the ventral margin of the subsquamosal, and extends dorsoposteriorly to the interparietal. Subsquamosal foramen is rounded, located immediately posterior to the dorsal surface of the base of the zygomatic process. Glenoid fossa broad and flat, abuts the postglenoid process posterolaterally. Postglenoid process moderately well-developed, narrows to a ventral point, and angled anterolaterally in ventral view, with the posteromedial component extending into and semi-fused with the anterior process of the ectotympanic to form a deep, anterior-facing ventral postglenoid foramen. Ectotympanic has a large, rugose anterior process projected ventral to and medial to the postglenoid process. External auditory meatus roughly cylindrical, angled dorsolaterally, not projected laterally beyond the margin of the anterior process of the ectotympanic and subequal in size.
Neurocranial region. Basioccipital broad, with concave ventrolateral surfaces, and a thin medial ridge that extends from the basisphenoid to immediately anteroventral to the base of the foramen magnum(Fig.37f); this ridge is very low to absent in juveniles. Alisphenoid posteroventral wing elongate; anterolateral surface of the centrum of the alisphenoid broad and gently convex, extends from the foramen ovale to the petrotympanic fissure. A thin crest projects anteromedially from the base of the paroccipital to merge with the posterior of the pterygoid crest, posteriorly abutted by a deep, rounded, quite large posterior lacerate foramen set into the medial base of the paroccipital process. Pterygoid with medial origin thin and tall, curves anteromedially to continue anteriorly into the pterygoid crest; pterygoid cavity broad, rounded and concave, bordered laterally by a tall, thin and distinct anteroposterior ridge extending from the posterolateral pterygoid crest to abut the medial margin of the foramen ovale.
Dorsal and posterior cranium. Parietal broad and convex. Temporal crest ossification pattern is as in P. anak. Nuchal crest low in juveniles, becomes very thickened and raised in adults, particularly laterally; crest extends ventrolaterally from the top of the supraoccipital before bifurcating around the mastoid foramen, with the lateral crest (mastoid-petrosal crest) extending ventrally to form the lateral margin of a short, blunt, slightly laterally flared mastoid process, and the medial (paroccipital) crest continuing ventrolaterally into the lateral margin of the elongate paroccipital process. Occiput is tilted slightly toward the posterior. Foramen magnum broad, oval and slightly compressed dorsoventrally, with a small Ushaped divot into the dorsal margin. Occipital condyles large, broad, gently curved ventromedially, oriented slightly dorsolaterally, extending beneath the foramen magnum, not extending dorsally beyond dorsal margin of the foramen magnum, tapered ventromedially in posterior view and projected posteriorly well beyond the margin of the occiput in lateral view. The dorsolateral margins of the supraoccipital are rounded with a flattened dorsal margin in posterior view; supraoccipital dorsoventrally short in juveniles; height increases relative to width with age, and dorsal margin thickens and flares dorsolaterally; posterior surface is pitted with four or more fossae, particularly the dorsal component, with the depth and the number of fossae increasing with age. A thickened, raised medial ridge runs dorsally from the dorsal margin of the foramen magnum, across the supraoccipital depression, to the centre of the nuchal crest.
The cranium of P. mamkurra sp. nov. differs from that of P. anak in being relatively broader, having a taller rostrum, shorter, broader,more ventrally situated,and more ventromedially curved occipital condyles, less posteriorly curved exoccipital, and in lacking a thin anterior jugal ridge; from P. viator sp. nov. in having a taller rostrum, shorter, generally broader, more ventromedially curved and generally more ventromedially situated occipital condyles, a more raised, more angular medial ridge on the basioccipital,, and a less posteroventrally curved exoccipital; from C. kitcheneri in being larger, relatively broader, more robust, and lacking a bony ‘pocket’ of the premaxilla within the nasal cavity, with a taller and more robust anterior component of the premaxilla, taller rostrum, larger masseteric process, much thicker and less laterally projected ventral orbital rim, taller zygomatic arch, broader, more curved, more ventromedially situated, and more posteriorly projected occipital condyles, a single anteroposterior ridge meeting medial margin of foramen ovale, and the anterior process of the ectotympanic extending to tip of postglenoid process, rather than wrapping around the posterior surface; and from W. bicolor in being much larger and lacking a small, pointed, anteriorly projected eminence on the anterior margin of the jugal, with a more ventrally projected anterior component of the premaxilla, taller rostrum, larger masseteric process, more robust palatine lacking fenestra, broader, more ventromedially situated and more posteriorly projected occipital condyles, a more raised anteroposterior ridge meeting the medial margin of the foramen ovale, relatively larger, more laterally extensive anterior process of the ectotympanic, and a taller, more laterally projected postglenoid process.
Upper dentition (Fig. 38): I1: broad, robust, arcuate, slightly anteroposteriorly compressed, with thick buccal enamel extending around to the edges of the lingual surface, receding from the lingual surface with age. Buccal surface smooth and gently convex. Occlusal surface oval, with buccal enamel forming a slight anterior lip; becomes anteroposteriorly deeper with age. The I2 is not known. I3: elongate, transversely compressed and roughly triangular in buccal view, with the buccal enamel width less than that of I1. A large, buccally gently convex main crest curves anterolingually to sit lingual to the posterior margin of the smaller anterobuccal crest; anterobuccal crest is around half the length of the main crest.
The cheek teeth are high-crowned. DP2: quite short, broad and oblong, broadening posteriorly, with thickened peaks over the anterior and posterior roots linked by a high main crest; morphologically very similar to P3 but anteroposteriorly truncated. Main crest blade-like, anteroposteriorly to slightly posterobuccally orientated, jagged to gently undulating in buccal view with a very low, dorsoventrally aligned ridgelet on the midpoint of the buccal surface. Lingual crest low, extends from the lingual base of the anterior cusp, lingually borders a broad, anteriorly tapering lingual basin, and meets the small, secondary posterolingual peak; a low ridgelet perpendicularly transects the midpoint of the lingual basin. Some specimens have the lingual crest meeting a small, secondary anterolingual peak at the lingual base of the anterior cusp. A small posterior basin abuts the posterior margin, sitting between the main and secondary posterior peaks; removed by a small amount of wear. DP3: broad and molariform, with the protoloph and metaloph markedly narrower than their swollen loph bases; anterior loph longer and narrower than the posterior loph. Precingulum small, narrower than the anterior loph, merges buccally with the thin and low but distinct preparacrista. Preprotocrista absent or very slight. Postparacrista thin and distinct, curves gently lingually into the interloph valley. Postprotocrista and postmetaconulecrista both thick, curving gently toward the midline of the tooth; postprotocrista continues onto anterior face of metaloph in some specimens. Postmetacrista short and thick.
P3: large and broadly oblong, tapers to a blunted point anteriorly; generally broader posteriorly, with thickened peaks over the anterior and posterior roots linked by a high main crest. In occlusal view, P3 is variably curved buccally toward its posterior, with the posterior part slightly swollen or expanded buccally and slightly rotated buccally, contributing to the variable crescentic shape of the tooth; broad and rounded posteriorly. Main crest high, blade-like, roughly anteroposteriorly orientated with a variable degree of posterobuccal curvature in occlusal view; slightly jagged to gently undulating in buccal view with two or three very low, roughly dorsoventrally aligned ridgelets around the centre of the buccal face, angled slightly toward the midpoint in buccal view. Anterior cusp generally slightly broader than the main crest + lingual crest, with a tall and pointed peak. Anterior peak intersected by a very brief transverse crest, perpendicular to the main crest, which dorsoventrally on the buccal and lingual surfaces, with the lingual ridgelet merging with the anterior margin of the lingual crest. Some specimens with one or two very small, low bumps on the base of the anterior or anterolingual surface of the anterior cusp, very occasionallymergingwithanunusuallyanteriorlyextensive lingual crest and linking the lingual crest to the anterior cusp. Lingual crest moderately tall, gently undulating in lingual view, extends from the lingual base of the anterior cusp to merge into the secondary posterolingual peak; lingually borders the broad, anteriorly tapering lingual basin; lingual basin V-shaped in cross-section, with one to three indistinct, very low ridgelets perpendicularly transecting the anterior component of the lingual basin. Posterior cusp tall and rounded, continuous with the main crest, which extends and broadens posteriorly to merge with the low, narrow transverse posterior crest. Small posterior basin located between main and posterolingual peaks, posteriorly bordered by the transverse posterior crest; removed by a small amount of wear. Posterolingual peak rounded, lower than the posterior cusp, and linked to the main crest by a thin transverse crest that anteriorly borders the posterior basin.
Molars: rounded-rectangular in occlusal view. Lingual and buccal margins of the lophs are slightly to moderately convex in posterior view, particularly the anterior lophs, with the protoloph and metaloph narrower than their bases; unworn protolophs and metalophs are gently concave posteriorly in occlusal view. Precingulum narrower than the anterior loph, slightly to moderately anteriorly projected, gently medially tilted, generally becoming slightly larger, broader and more projected toward M4; flat, broad and shelf-like when worn; width variable within individuals (see cingula of left and right M2 of paratype SAMA P28163); some specimens (e.g. WAM 2020.6.276) with small enamel crenulations on the occlusal surface. Preprotocrista absent or very slight. Preparacrista absent or low and indistinct (Fig. 38d). Postparacrista quite well-developed immediately posterior to the paracone, becomes thinner and less raised toward interloph valley, curves lingually to be adjacent to or merge with the buccal component of the postprotocrista in the interloph valley. Postprotocrista relatively thicker and more raised, particularly in the interloph valley, curves from the protocone to near the midpoint of the interloph valley; continues as a thin and indistinct crest towards metaconule, merging into anterior face of metaloph. Interloph valley slightly narrower than the lophs, occasionally broader in M1 and very rarely in M2. Some specimens with a very small, rounded cusp on the base of the protoloph on the buccal margin of the interloph valley (Fig. 38f), and/or with a very small, rounded cusp on the base of the metaloph in the interloph valley abutting the lingual margin, presence very variable, with either or both cusps variably present in DP3 (e.g. QVM2000 GFV10) or on one or more molars, anywhere along the molar row, sometimes present on only one side of the dentition. Premetacrista very slight, extends from the metacone to meet the base of the postparacrista in the interloph valley. Postmetaconulecrista quite thick and raised, arises from the metaconule and curves dorsobuccally to form a small, oblique shelf beneath the posterior basin. Postmetacrista lower, shorter and less distinct, arises from the metacone, deflects lingually to merge into the buccal margin of the posterior basin.
The upper dentition of P. mamkurra sp. nov. differs from that of P. anak, P. otibandus and P. snewini in having a DP3 lacking a large, distinct preprotocrista forming half of an incomplete protoloph. It further differs from P. anak in being generally slightly larger, with broader I1 relative to the length of I3, relatively broader DP2, particularly across the anterior cusp, P3 with a higher, less jagged and more anteriorly extensive lingual crest and lower, less transversely aligned and less distinct transverse ridgelets, generally relatively broader molars with a lower postprotocrista and slightly stronger postparacrista, and M1–2 with a weaker preparacrista; from P. viator sp. nov. in being generally smaller, with P3 with a slightly narrower anterior relative to length and a relatively narrower anterior loph of M1; from P. tumbuna in being larger and higher crowned, with broader,anteroposteriorly shorter I1 lacking a posterobuccal bulge in cross-section, DP2 lacking a small anterolingual crest linking the anterior cusp and lingual crest, relatively narrower P3, and generally less rounded molars in occlusal view with no urocrista present; from P. dawsonae sp. nov. in having I1 broader relative to I3, P3 with slightly less distinct buccal ridgelets, relatively narrower posterior molars, and molars with a lower and less distinct preparacrista, no preprotocrista, and a gently curved postparacrista; from P. otibandus in being larger and higher crowned, with broader, anteroposteriorly shorter I1 lacking a posterobuccal bulge in cross-section, DP2 and P3 with less distinct buccal ridgelets, and molars lacking a urocrista; from P. snewini in being larger and higher crowned, with relatively broader P3 across the posterior cuspule; from C. kitcheneri in being larger and higher crowned, with larger incisors relative to size of cranium, broader I1 relative to I3, absolutely and more elongate P3 and relatively slightly narrower molars; and from W. bicolor in being much larger and higher crowned, with relatively broader I1, P3 with a higher lingual crest and a larger posterior basin, and molars with a thicker postprotocrista distinctly extending to the protocone, rather than merging into the centre of the posterior surface of the protoloph.
Dentary (Fig. 39a–d): tall and robust. Dentaries diverge from sagittal plane at ~30° from the axis of the symphysis in dorsal view. Diastema moderately long, increasing in length with age; between half and two-thirds of height of mandibular corpus; dorsal margin level to slightly dorsally deflected, and ventral margin very gently convex, such that first incisor is orientated somewhat dorsally. Mental foramen round to oval, opens laterally, positioned midway between the midpoint and dorsal margin of the lateral surface of the diastema, around one-third of the diastema length from the dp2/p3. Mandibular corpus tall, slightly deeper beneath m1 than m4. Buccinator sulcus distinct but quite shallow, extends along the buccal surface of the mandibular corpus, slightly ventral to and parallel to the three anteriormost cheek teeth. Digastric sulcus generally shallow and broad, situated on the ventral part of the lingual surface of the mandibular corpus, extending roughly from ventral to the base of the coronoid crest to ventral to m2/m3. Ascending ramus tall and quite robust, slightly concave laterally and convex medially. Coronoid crest angled around 70–85° from transverse plane, smoothly convex anteriorly, ascends to rounded, anteroposteriorly short peak; some specimens with slight, rounded corner or elbow at midpoint. Dorsoposterior margin of the coronoid process is deeply concave, curves anteroventrally before levelling out at or slightly ventral to the anterior margin of the mandibular condyle.
Masseteric fossa large and shallow, bounded anteriorly and ventrally by low ridge; margins broadly rounded to U-shaped in lateral view. Masseteric foramen oval and elongate; abuts the anterior margin of the masseteric fossa and shares the anterior part of its lateral lip. Masseteric dental canal deep, separated from the mandibular foramen and the inferior dental canal by a narrow dorsal crest running anteroposteriorly. Medial pterygoid fossa very concave, deep and broad, broadens posteriorly; posteromedial extremity is squared and posterior margin is straight in dorsal view. Mandibular foramen round to oval and transversely compressed; opens posteriorly and slightly medially; located in the anterolateral part of the medial pterygoid fossa at the ventral base of the medial surface of the ascending ramus. Angular process is a thin, elongate crest, quite dorsally and slightly posteriorly projected such that the posterior extremity is level with that of the mandibular condyle. Ventral and posteroventral margin of the dentary similar to that of P. anak. The condylar process is not posteriorly projected. Mandibular condyle oval, slightly anteroposteriorly compressed, rotated slightly laterally in dorsal view and tilted medially; occasional a small, rounded eminence extends from the anteromedial margin. Ontogenetic change similar to that of P. anak.
The dentary of P. mamkurra cannot be differentiated from that of P. viator sp. nov. nor P. dawsonae sp. nov. Differs from that of P. anak being broader and more robust, with a shorter, more dorsally deflected diastema relative to the tooth row length; from P. tumbuna in being generally larger, with a relatively shorter diastema and more anterodorsally situated mental foramen; from P. otibandus in being generally slightly more robust, particularly in the diastema; from P. snewini in being larger, deeper and more robust, with a more dorsally deflected diastema, slightly more ventrally situated mental foramen, and a less posteriorly projected angular process; from C. kitcheneri in being larger and more robust, with a relatively shorter, more dorsally deflected diastema, more posteroventrally situated mental foramen, taller mandibular corpus, deeper buccinator sulcus, anteroposteriorly longer coronoid process, a larger dorsal septum partially separating the masseteric and mandibular foramina, deeper medial pterygoid fossa with higher posterior margin, and a relatively dorsally situated masseteric fossa; and from W. bicolor in being much larger, with a more dorsally deflected diastema, deeper buccinator sulcus, broader, more oval mandibular condyle, and a larger dorsal septum partially separating the masseteric and mandibular foramina.
Lower dentition (Fig. 39d–f): i1: large, procumbent and slightly to moderately dorsally deflected, broad and buccally tilted; acuminate when unworn, becoming shorter and rounder in cross-section with wear; enamel completely covers the buccal surface; dorsobuccal margin with thin, raised enamel crest; enamel thick and rounded around the ventrolingual margin, lacking ventrolingual crest (Fig. 39f), covers the ventral half of the lingual surface when unworn, with the lingual enamel layer tapering posteriorly such that well-worn i1s lack lingual enamel.
Tooth row roughly straight and parallel in occlusal view, very slightly convex in juveniles; in lateral view, tooth row slopes slightly ventrally toward the posterior, with the rate of wear along tooth row highly variable as a result of the variable degree of the tooth row angle. dp2: morphologically very similar to p3 but anteroposteriorly truncated; tall and triangular in cross-section, roughly oblong to mucronate in occlusal view, broadens gently to its posterior. Main crest thin, aligned anteroposteriorly, extends from over the anterior root to over the posterior root and twists lingually to end over the posterolingual extremity; an indistinct dorsoventrally aligned ridgelet is located around the midpoints of the buccal and lingual surfaces.Anterior cuspid semi-distinct from the main crest, being slightly broader, with very slight dorsoventrally aligned posterior ridgelets. dp3: molariform, very similar to the morphology of m1 but relatively narrower. Both lophids crests significantly narrower than bases, protolophid narrows slightly more; both lophid crests slightly convex posteriorly in occlusal view when unworn to moderately worn. The lophid bases are slightly bulged buccally. Precingulid moderately developed, narrower than the trigonid, and tapers anteriorly. Paracristid thin and raised; lingual component anteroposteriorly aligned, curves smoothly posterobuccally to the protoconid; wears quickly. Premetacristid narrow and moderately anteriorly projected, contributing to quite deep and rounded trigonid basin. Postprotocristid thin and indistinct, lingually deflected to midpoint of the base of interlophid valley and merges with lingual component of cristid obliqua; wears quickly. Cristid obliqua quite tall and slightly thickened, curves posterobuccally to hypoconid. Preentocristid distinct, slightly thickened, anteriorly projected from entoconid.Postcingulid small, shelf-like, slightly narrower than posterior of talonid base.
p3: elongate and oblong in occlusal view, typically with slight waist, occasionally with parallel margins or slight transverse bulge around the midpoint; typically broader across posterior root than anterior root but occasionally subequal; tall and triangular in cross-section. Main crest; blade-like, straight, anteroposteriorly linking pointed anterior cuspid and blunt, posteriorly rounded posterior cuspid; twists slightly to moderately lingually past posterior cuspid; buccal and lingual surfaces have one to three indistinct, roughly dorsoventrally aligned ridgelets that extend to peak of crest, such that unworn and slightly worn crest appears slightly jagged in buccal view. When unworn, a very brief transverse crest intersects the main crest and anterior cusp perpendicularly, extending down from peak to form slight posterior-facing ridgelet. The anterior base of the anterior cuspid occasionally has a small, irregular bump projected slightly anteriorly or anterolaterally.
Molars: high-crowned, quite broad and rounded in occlusal view, with the interlophid valley narrower than the lophid bases; when unworn or slightly worn, the protolophid and hypolophid crests are posteriorly convex or have an oblique mesial kink toward the posterior; lingual component of the hypolophid is slightly posteriorly tilted, becomes straight and perpendicular to tooth row centreline with moderate wear. The buccal margins of the lophids are slightly more convex than the lingual margins in posterior view. Precingulid moderately developed, typically narrows to a rounded point. Paracristid with lingual component large and square; buccal component thick and raised, extends straight posteriorly before curving dorsobuccally to the protoconid. Protolophid and protoconid enamel ‘folding’ is similar to that of P. anak. Premetacristid very low, often indistinct or absent, extends from the lingual margin of the trigonid basin to the metaconid. Cristid obliqua thick and generally low, arises from slightly buccal to the midpoint of the interlophid valley, curves very slightly buccally and extends to the hypoconid (Fig. 39e–f). Preentocristid very low, broad and indistinct, arises midway between the base of the cristid obliqua and the lingual extremity of the interlophid valley and deflects slightly lingually as it rises to the entoconid. When little worn, the hypoconid is distinctly taller than the entoconid and is slightly lingually displaced. Postcingulid narrow and slight on m1 and 2, typically becoming more broader and shelf-like in m3 and particularly m4; occasionally present as a wrinkled bulge on the posterior lophid base.
The lower dentition of P. mamkurra sp. nov. differs from that of all other species of Protemnodon except P. viator sp. nov. in having a broader posterior of the p3 relative to length. It further differs from P. anak in having a broader i1 with a lower dorsobuccal crest and no ventrolingual crest, slightly broader dp2, p3 with fewer, lower and less distinct ridgelets on the main crest, generally slightly larger molars with a smaller precingulid, more convex buccal lophid margins when slightly worn, and a lower, less distinct cristid obliqua when unworn or slightly worn; from P. viator sp. nov. in being generally smaller; from P. tumbuna in being larger and higher crowned, with a relatively larger, broader i1 with no ventrolingual crest, and m3 and m4 with less convex buccal lophid margins and a lower premetacristid; from P. dawsonae sp. nov. in being generally larger and higher crowned, with the i1 lacking a low, thick ventrolingual crest; from P. otibandus in being larger and higher crowned, with relatively larger, broader i1 lacking a ventrolingual crest, and m3 and 4 with less convex buccal lophid margins; from P. snewini in being larger and higher crowned, with relatively larger, broader and more dorsally deflected i1 lacking ventrolingual crest and with enamel more extensive across ventral component of lingual surface, p3 with fewer, less distinct ridgelets on main crest, and molars with larger premetacristid and smaller precingulid; from C. kitcheneri in being larger and higher crowned, with a broader and more spatulate i1 lacking a ventrolingual crest, relatively broader deciduous premolars, larger and more elongate p3, and molars with narrower lophid crests and a postcingulid; and from W. bicolor in being much larger, with a broader and more spatulate i1 lacking a ventrolingual crest, p3 with less raised and less distinct ridgelets on the main crest, and molars with a generally more anteriorly prominent precingulid and a thicker, lower cristid obliqua.
Axial skeleton
Atlas (C1) (Fig. 40): large and broad. Arch slightly cranially inclined, craniocaudally short, with dorsal tubercule situated cranially between two shallow fossae containing small foramina. Wings weakly developed in juveniles, relatively larger in adults; dorsoventrally compressed and slightly caudally deflected, with the cranial and caudal margins not extending past those of the cranial or caudal articular foveae. Cranial articular surfaces deep and strongly concave, dorsal margins are rounded, ventral margins come to a ventromedial rounded point; shallow fossa at the midpoint of the medial margin in juveniles, absent to very slight in adults. Caudal articular surfaces broad, flat to very slightly concave and angled roughly 40° medially from the sagittal plane, with the dorsal margin rounded; ventral section comes to a rounded ventromedial point; ventral margins relatively separate in juveniles, converging with age. Lateral vertebral foramen situated in a small, deep fossa on the dorsal surface of the arch at the cranial base of the wing, opening laterally (Fig. 40e).
The atlas vertebra of P. mamkurra sp. nov. differs from that of P. anak in being craniocaudally shorter and more dorsoventrally compressed; from P. viator sp. nov. in having lateral vertebral foramina that open laterally instead of caudally, and less caudally projected and extensive wings; from C. kitcheneri in being broader and craniocaudally shorter relative to height, with less cranially projected, less dorsally concave cranial articular surfaces and less medially tilted caudal articular surfaces; from O. rufus in being generally larger, with more caudally deflected wings, larger dorsal tubercle, less dorsally concave and less cranially projected cranial articular surfaces, and more ventrally situated caudal articular surfaces; from M. fuliginosus in being larger, and broader relative to height, with a larger dorsal tubercle, more caudoventrally situated lateral vertebral foramina, less dorsally concave cranial articular surfaces, and more caudally deflected wings; and from W. bicolor in being larger, with a larger dorsal tubercle, more dorsoventrally aligned cranial articular surfaces, more dorsoventrally aligned and less medially tilted caudal articular surfaces, and shorter ventromedial processes.
Axis (C2) (Figs 40a–b & 41a–d): craniocaudally short and broad; centrum broader than its depth, with height subequal to depth. The dens is robust and slightly dorsally deflected (Fig. 41a). Cranial articular surfaces gently convex, with the articular surfaces angled roughly 40–45° fromthesagittalplane;lateralhalvesnotpreserved.Spinous process elongate, with the lateral surfaces gently concave in cranial view; dorsal margin straight in lateral view, gently inclined cranially, thickened and projected cranially beyond the margin of the arch (Fig. 41a), not extending cranially past the margin of the centrum and the cranial articular surfaces, bulging at the caudal end, projected caudally beyond the margin of the postzygopophyses. The vertebral canal is oval and dorsoventrally flattened. The width of the centrum tapers caudally. Transverse foramina round, positioned at the caudal end of the centrum in lateral view, bounded ventrolaterally by a thin, delicate ridge. Transverse processes small, not extending laterally beyond the margin of the postzygopophyses. Postzygopophyses small, with tear-drop shaped articular surfaces. Caudal extremity of the centrum very slightly projected caudally, not extending past the margins of the transverse processes, postzygopophyses and spinous process; the lateral margins are level with the medial margins of the postzygopophyses in caudal view.
The axis vertebra of P. mamkurra sp. nov. differs from that of P. anak in being much shallower relative to width, with a shorter and more dorsally deflected dens, more convex and dorsolaterally tilted cranial articular surfaces, smaller, more rounded postzygopophyses, a more caudally projected spinous process with a more cranially tilted dorsal margin, and a much less caudally projected caudal extremity of the centrum; from P. viator sp. nov. and P. dawsonae sp. nov. in being shallower relative to width, with a less caudally projected caudal extremity of the centrum; from C. kitcheneri in being larger, and shallower relative to width, with a lower, more cranially tilted and caudally extensive spinous process, smaller, less elongate postzygopophyses, and relatively larger, broader and less caudally projected caudal extremity of the centrum; from O. rufus in being shallower relative to width, with the caudal extremity of the centrum less caudally projected; from M. fuliginosus in being larger, and shallower relative to width, with a more caudally projected spinous process; and from W. bicolor in being larger and relatively broader, with a more rounded dens, less laterally tilted cranial articular surfaces, a relatively smaller spinous process with a straight (rather than convex) dorsal margin and a broader, slightly less caudally projected caudal extremity of the centrum.
Cervical vertebrae (C3–7) (Figs 40a–b & 41e–h): C5 is not known. The articulated neck is distinctly short relative to the width of the cervical vertebrae. The cervical vertebrae are roughly pentagonal in cranial view, with arches tilted cranially; centrum and arches very short relative to width; increasingly short toward C7. Cranial extremity of the centrum very broad relative to height, and slightly concave, particularly at the lateral margins, which are slightly cranially projected. Prezygopophyses small, not extending cranially past cranial extremity, with articular surfaces rounded in C3, becoming more elongate and oval toward C7, narrower than length and angled slightly to moderately medially; no ridge separates the articular surface from the dorsal surface of the arch. Spinous processes not preserved in entirety; bases narrow, becoming broader and slightly more cranially tilted towards C7. Vertebral canal low and rounded in C3, becoming taller toward C7 and approaching rounded-triangular in shape. Transverse processes mostly abraded; poorly developed in juveniles, becoming relatively broad and thickened with age; caudally deflected and craniocaudally short in C3, becoming decreasingly caudally deflected and slightly deeper toward C7; tubercle on the ventral base of the transverse processes is elongate, transversely thickened and ventrally projected in C6 such that the ventral margin of the centrum is concave in cranial view, with the tubercle broader, shorter, slightly pointed, more cranially situated and tilted cranially in C7. Postzygopophyses small, typically not extending beyond the caudal extremity of the centrum, with the articular surfaces slightly to moderately laterally tilted, roughly circular in C3, becoming slightly elongate and oval toward C6–7. Caudal extremity unprojected, very broad relative to height, flat in dorsal view, and very slightly convex around the lateral margins in caudal view.
The cervical vertebrae of P. mamkurra sp. nov. differ from those of P.anak in being craniocaudally much shorter, with a lower, broader cranial extremity of the centrum, smaller, less cranially projected and less cranially tilted prezygopophyses, a less horizontal, more roof-like arch (Fig.41h), smaller postzygopophyses and a lower, broader, much less caudoventrally projected caudal extremity of the centrum; from P. viator sp. nov. in being craniocaudally shorter relative to width, with a less horizontal, more roof-like arch, slightly smaller pre- and postzygopophyses, and a less caudoventrally projected caudal extremity of the centrum that lacks a slightly bilobed ventral margin (Fig. 41h); from P. tumbuna in having a considerably taller C3, with relatively broader cranial and caudal articular surfaces and a much more dorsally deflected, less horizontal arch in cranial view; from C. kitcheneri in being relatively taller and craniocaudally shorter, with a shorter, broader cranial extremity of the centrum, smaller, less craniolaterally projected prezygopophyses, a more dorsally projected, roof-like arch, smaller, less caudolaterally projected postzygopophyses, and a shorter, broader and less caudally projected caudal extremity of the centrum; from O. rufus and M. fuliginosus in being broader and less elongate, with smaller and less laterally projected pre- and postzygopophyses, a deeper, more transversely compressed spinous process, a less concave cranial extremity of the centrum and less convex, less caudally projected caudal extremities; and from W. bicolor in being larger and relatively slightly taller, with the vertebral canal taller and more rounded-triangular in C6–7, and with the ventral tubercles of the transverse processes present as small, pointed, cranially tilted eminences on C7.
Thoracic vertebrae (T1, 3, 7, 12–14) (Fig. 42): vertebrae craniocaudally short relative to width, with centra increasing in height and depth toward T14; diapophyses (fovea costales processus transversi) are short and robust in T1–3, migrating dorsally onto arch and becoming dorsally deflected by T7, becoming shorter and more robust in T12–14 (situated dorsal to cranial articular facets in T12 only); caudal foveae large and dorsolaterally flared such that the caudal extremity appears heart-shaped in caudal view. T1: cranial extremity of the centrum unprojected, dorsoventrally very short relative to width, and very slightly concave; caudal extremity of the centrum unprojected, badly abraded in available specimens. Prezygopophyses small and short, with the articular facets circular to oval and tilted medially. The arch is low and robust. Spinous process tall, straight in lateral view, with parallel cranial and caudal margins, relatively thick at base and narrowing gently dorsally. The cranial margin of the ventral surface has deep, semicircular costal foveae (demifacets) for articulation with rib 1. Diapophyses slightly ventrally tilted.
T3: cranial extremity of the centrum slightly ventrally tilted, with concave dorsal margin and broadly rounded ventral and lateral margins in cranial view. Prezygopophyses small and short, articular facets circular to oval and laterally tilted. The arch is fairly low and robust. Spinous process tall, thick at the base and narrowing dorsally, with a small caudal eminence on the tip.T7:cranial extremity has gently concave dorsal margin. Prezygopophyses small and short, with articular facets circular to oval and tilted laterally. The arch is robust, and taller than in T3. Spinous process tall, thickened at the base, narrows dorsally, with a small caudal eminence on tip; caudally deflected in lateral view; slightly lower than in T3.
T12 is the ‘transitional’ thoracic vertebra, the last vertebra possessing smaller, dorsal facing, cranially projected prezygopophyses but with differentiated postzygopophyses which articulate with enlarged, dorsomedial facing, strongly dorsally projected prezygopophyses is. T12 is also the anticlinal vertebra within the thoracic spine, with cranial extremities of T13–14 slightly dorsally inclined. T12: cranial extremity has concave dorsal margin. Prezygopophyses small and short, with articular facets circular to oval and tilted laterally. Only the caudal foveae are present on T12–14, with size decreasing toward T13, present in T13 and 14 as a slight outward rotation of the lateral margins of the caudal extremity. Spinous process less tall than in T1–7, narrow, deep and caudally deflected, with straight cranial margin and gently concave caudal margin. T13 and 14: prezygopophyses are greatly enlarged, taller, cranially projected and laterally deflected with articular facets medially inclined. Caudal accessory processes, ancillary to postzygopophyses, are present on T13 as small tubercles on caudal surfaces of diapophyses and on T14 as marked triangular eminences arising on caudal surface midway between arch and diapophyses. Spinous process straight, deeper than in T12, and with very slightly concave to straight caudal margin.
The position of the transitional thoracic vertebra is T 12 in P. mamkurra sp. nov. and P. viator sp. nov., while all compared non– Protemnodon taxa except C. kitcheneri have this transitional vertebra at T11. The thoracic vertebrae of P. mamkurra sp. nov. are not differentiated from those of P. viator sp. nov. They differ from those of P. anak in having the centra of the cranial thoracic vertebrae (T1–3) relatively shorter and broader; from C. kitcheneri in being larger, with T1, 3 and 7 craniocaudally shorter relative to width, the spinous processes of T1 and 3 less transversely compressed, and the diapophyses of T7 more dorsally deflected; differ further from those of O. rufus in being craniocaudally shorter relative to width, with spinous process of T7 less caudally deflected, and taller, more craniodorsally situated cranial articular surfaces and more dorsally situated postzygopophyses on T12 and 13; from M. fuliginosus in being generally larger, and longer relative to width, with more dorsally situated postzygopophyses on T12 and 13; and from W. bicolor in being larger with a relatively taller centrum, and in T12 and 13 having less cranially deflected prezygopophyses and more dorsally situated diapophyses.
Lumbar vertebrae (L1–5) (Fig. 43): large and robust; width and depth of centra subequal, increasing in absolute size towards L5; ventrolateral surfaces of centra strongly concave. Prezygopophyses large, projected cranially well beyond the margin of the centrum and angled craniodorsally from base before deflecting dorsally around the midpoint, with the cranial articular surfaces small, slightly rugose and oval. Spinous processes quite tall and robust in L1–2, becoming less deep and more gracile toward L5. Postzygopophyses quite small and rounded with the articular surfaces oval and tilted laterally and slightly ventrally. A short, broad, ventral ridge is present on L1 and 2, thickens caudally along the centrum. Caudal accessory processes of L1 and 2 are lobe-shaped, dorsocaudally projected processes that arise cranioventral to the bases of the postzygopophyses.
L1: cranial and caudal extremities of the centrum rounded with gently flattened dorsal margins.The vertebral canal is narrow and domed. Spinous process deep, and thickened at the base. L2: cranial extremity rounded, and caudal extremity distinctly oval with broadly flattened dorsal margin. The vertebral canal is broad and oval. Transverse processes small, planar, cranially deflected, situated slightly dorsal to midpoint of craniolateral margin of cranial extremity of the centrum. Small anapophyses are present on the lateral margin of the caudal extremity in L2 and 3, very reduced in L4–5. L3–5: cranial and caudal extremities of the centrum oval with broadly flattened dorsal margins. The vertebral canal is semicircular in L3 and 4, broader and more domed in L5. Caudal accessory processes present only as small rugose tubercles in L3 and as very small, pointed, caudally projected eminences on L4–5. Transverse processes shift dorsally and caudally towards L5 to be positioned on the pedicle, becoming longer, deeper and more planar in profile.
The lumbar vertebrae of P. mamkurra sp. nov. are not confidently differentiated from P. viator sp. nov. differ from P. dawsonae sp. nov. in being larger, with shallower transverse processes and centrum, relatively taller, slightly narrower cranial and caudal extremities, less concave ventrolateral faces, a less concave ventral margin, and a more raised ventral ridge; from C. kitcheneri in being larger and more elongate; from M. fuliginosus and O. rufus in being larger and more robust, with five (rather than six) lumbar vertebrae, taller centra more circular in cranial view, and lacking distinct twinned dorsal canals; and from W. bicolor in being larger and in numbering five. Sacrum (S1–2, 3) (Fig. 44a–d): large to very large, made up of two or three robust, fused vertebrae; roughly triangular in dorsal view. Cranial extremity of the centrum is oval. The vertebral canal is roughly crescentic to reniform. Prezygopophyses fairly small, cranially projected with slight dorsal deflection; articular surfaces small, slightly craniocaudally elongate and facing dorsomedially; dorsal margins not preserved. Wings well-developed, sub-triangular in lateral view, expand toward lateral edges, particularly ventrally, and taper caudally; auricular surfaces tilted dorsally; a broad, rugose, deeply concave fossa is present on the dorsolateral surface of each wing. The median sacral crest (fused spinous processes) is not preserved. Transverse processes thicker in the cranial component, become more dorsoventrally compressed and flare laterally in the caudal component. Two large, round sacral foramina pass dorsoventrally through the sacrum at the synostoses of the fused S1 and S2 vertebrae. Postzygopophyses short, quite robust, projected caudolaterally, with the articular surfaces flat and rounded, angled ventrolaterally. The caudal extremity of the centrum is taller and more rounded than the cranial extremity.
The sacrum of P. mamkurra differs from that of P. anak in having a larger, more deeply concave fossa on dorsolateral surface of the wings; from O. rufus in being larger and more robust, with a broader vertebral canal, more dorsally tilted auricular surfaces, and a broader caudal component; and from M. fuliginosus in being larger, with the centrum relatively taller in cranial view and lacking small, shallow fossae either side of the craniodorsal midline, the vertebral canal relatively broader, lower and roughly crescentic (rather than an inverted ‘heart’ shape), the auricular surface relatively more extensive craniodorsally and caudally, S 2 in ventral view relatively broader, more robust, and having only two sacral foramina between S1 and S2 (whereas in M. fuliginosus there is an extra pair around the midpoint of the dorsal surface of S1).
Caudal vertebrae (Ca1?–12) (Fig. 44d–j): short, broad and robust. Centra: of Ca1–4 are broader than they are long; of Ca1–5 (proximal caudal vertebrae) are craniocaudally short, with slightly ventrally inclined cranial and caudal extremities; of Ca6 onward are straighter and more elongate; Ca9–12 (mid-distal caudal vertebrae) are quite short and robust, narrow to a waist. The vertebral canal is very low and broad in Ca2, becoming increasingly low toward Ca5, extremely small in Ca6–8 and absent in mid-distal vertebrae. Prezygopophyses: in Ca1–4 are large, laterally projected, dorsally deflected and distally flared, with articular surfaces angled dorsomedially and projected craniomedially; in Ca5, are large, dorsally deflected, and extend beyond the cranial extremity of the centrum; in Ca6–12, are increasingly reduced, as mammillary processes, without articular surfaces. Postzygopophyses: in Ca1–4, are relatively small and unflared distally with small, rounded articular surfaces; in Ca5, are very reduced, narrow, non-articular, that do not extend caudally beyond the caudal extremity; in Ca6–12, are increasingly reduced that shift caudally to abut the caudal margin as low, thin, parallel ridges in the distal vertebrae. Transverse processes: those of the proximal vertebrae are fractured and incomplete; on Ca1, are deep; on Ca2, very elongate laterally; become increasingly shorter craniocaudally and more caudally deflected towards Ca5; in Ca6–7, depth greater than width; in Ca8, very reduced cranial transverse processes; in Ca9–12, small, thick, and blunt, cranial processes relatively larger than caudal. Spinous processes: in Ca1–4 are rounded, increasingly small; very reduced or absent in Ca5 onward. Cranioventral processes: small, blunt, ventrally projected, first present on Ca6, are positioned close to the midline and curve gently mesially; become more mesially curved and taller, thicker, and more elongate relative to vertebrae distally.
The caudal vertebrae of P. mamkurra differ from those of P. anak being generally slightly more robust and in having smaller mammillary and caudal transverse processes on Ca7; from P. viator in being shorter and more robust, with the Ca7 caudal transverse processes and Ca8 cranial processes narrower and more caudally curved; from P. tumbuna in being larger; from C. kitcheneri in having the proximal vertebrae with slightly more ventrally deflected transverse processes and less ventrally facing cranial extremities, and the distal vertebrae with relatively thick cranial transverse processes; from O. rufus in being craniocaudally shorter relative to width, with the caudal transverse processes on Ca4–7 longer relative to the length of the centrum; from M. fuliginosus in having a smaller spinous process in Ca1–4, shallower, broader and distally more rounded transverse processes in the proximal vertebrae, and relatively more robust distal vertebrae; and from W. bicolor in being larger and more robust, with generally more transversely compressed tips of the mammillary processes, and the caudal transverse processes on Ca4–7 longer relative to the length of the centrum.
Forelimb and pectoral girdle
Clavicle (Fig. 45a–f): craniocaudally compressed along the shaft and at acromial articular end. Clavicle curves gently posteriorly towards the acromial end in cranial view, gently convex along the anterior margin. Sternal articular end not preserved. Laterally, it expands in depth steadily to a large, slightly thickened, distinctly caudally curved acromial end and comes to a blunted point.
The clavicle of P. mamkurra differs from that of P. otibandus in being slightly more robust and less craniocaudally compressed, with a slightly larger acromial articular end relative to the size of the clavicle; from C. kitcheneri in being larger, deeper and more craniocaudally compressed, with a relatively larger acromial end; from O. rufus and M. fuliginosus in being slightly more robust, with a slightly more caudally curved and less posteriorly curved acromial end; and from W. bicolor in being much larger and deeper, with a more caudally curved acromial end with more pointed tip.
Scapula (Fig. 45g –i): only the juvenile scapula is known, which is gracile and delicate. Lateral (humeral) component of the cranial border is very slightly concave. Infraspinous fossa partially preserved; appears significantly larger than the supraspinous fossa. Glenoid cavity oval and gently concave, with slight anteroposterior compression. Infraglenoid tubercule unprojected and slightly rugose, with a small, broad fossa present on the medial component. Scapular spine slightly cranially deflected in lateral view. Acromion incompletely preserved; interpreted as being quite elongate, broadening distally, with dorsolateral surface flat and broad. Scapular notch gently concave, with an angle of ~120°. Lateral component of the subscapular fossa planar to gently concave caudally, moderately concave beneath the scapular spine and becoming gently convex toward the cranial border.
The scapula of P. mamkurra sp. nov. cannot be differentiated from that of P.viator. It differs from that of P. anak in a having thicker, less medially extensive scapular spine; from C. kitcheneri in having a less anteroposteriorly compressed glenoid cavity with a less anterolaterally projected glenoid tubercle and coracoid process, a small, broad fossa on the infraglenoid tubercule, and a slightly concave (rather than straight) lateral component of the caudal border; from O. rufus in having craniocaudally shallower scapular neck, less cranially tilted spine and broader scapular notch; from M. fuliginosus in having a slightly less elongate glenoid cavity, a small, broad fossa on the infraglenoid tubercule, and a slightly less cranially deflected scapular spine; and from W. bicolor in being larger, with a craniocaudally shallower neck, thicker, less medially extensive spine, more robust acromion, and a broader scapular notch.
Humerus (Fig. 46a–d): broad and robust, with thick, well-developed proximal muscle attachments. Head roughly hemispherical, rounded and moderately projected caudally. Greater tubercule broad, projected marginally dorsal to articular surface of head. Lesser tubercule not preserved, base appears broad and rounded. Proximal shaft deep, deepening proximally; in cranial view, shaft possesses slight to moderate medial deflection, with axis situated across shaft at pectoral crest. Bicipital groove broad and shallow in juveniles, becomes deeper, slightly narrower and more distally extensive in adults. Pectoral crest thick, raised and slightly laterally tilted, situated at or just past the midpoint of the humeral shaft; becomes higher and more pronounced proximally with age. Deltoid tuberosity low in juveniles, becomes thicker, more rugose and slightly pointed in adults, situated on the lateral surface of the shaft, level with the proximal half of the pectoral crest. Insertion of m. latissimus dorsi located on the medial surface of the shaft opposite the deltoid tuberosity, marked by a small rugose area in juveniles and by a broad, shallow, irregularly shaped fossa in adults.
Distal end short, broad, and roughly triangular in cranial view. Lateral supracondylar ridge quite narrow, extends around one-third of the humeral length, with the proximal margin coming to a small, rounded point two-thirds of the distance from the trochlea to the pectoral crest (Fig. 46a). Capitulum and ulnar facet large, robust, laterally situated, abutting the lateral epicondyle, width roughly two-thirds of total distal width; capitulum smoothly and strongly convex, with lateral margin rounded and gently tapering; ulnar facet with the medial margin relatively straight and slightly bevelled. The trochlea is wide and quite shallow. The olecranon fossa is moderately deep and slightly medially displaced. Radial fossa quite small, variable in depth; deep relative to smaller, shallower coronoid fossa positioned immediately proximal to trochlea. Medial supracondylar bridge broad, thin craniocaudally; supracondylar foramen elongate and strongly flattened craniocaudally.
The humerus of P. mamkurra sp. nov. differs from that of P. anak in being shorter, with a shorter bicipital groove, shorter pectoral crest, less distinctly straight and raised medial margin of ulnar facet, and a relatively shorter lateral supracondylar ridge with a more pointed proximal peak; from P. viator in having the proximal peak of the lateral supracondylar ridge more pointed and relatively further from the distal extent of the pectoral crest; from P. tumbuna in being more robust, with a shorter, broader distal end, and in lacking a low, broadly rounded ridge linking the pectoral crest and the medial supracondylar bridge; from C. kitcheneri in being relatively shorter and more robust, with a more medially projected head, taller and deeper greater tubercle, more deeply concave bicipital groove, much deeper proximal shaft, generally lower and less elongate deltoid tuberosity, much lower, less elongate, less distally extensive and straighter pectoral crest, and broader medial and lateral supracondylar ridges, and in lacking a crest on the distal margin of the attachment site for m. latissimus dorsi; from O. rufus in being more robust, with a deeper greater tubercle and proximal shaft, more deeply concave bicipital groove, more distally situated pectoral crest relative to the deltoid tuberosity, broader and relatively shorter distal end, and more pointed proximal peak of lateral supracondylar ridge; from M. fuliginosus being more robust, with a deeper and taller greater tubercle, deeper proximal shaft, more deeply concave bicipital groove, much broader capitulum, ulnar facet and distal end, broader, shallower and less concave olecranon fossa, and a shorter, thicker deltoid tuberosity and pectoral crest; and from W. bicolor in being larger, with a more medially projected head, taller and deeper greater tubercle, deeper, less raised and less elongate deltoid tuberosity, less raised, straighter, less extensive pectoral crest, broader distal end, and a broader medial supracondylar bridge.
Ulna (Fig. 46e–g): quite short, robust and gently transversely compressed, much more gracile in juveniles. Olecranon quite long relative to the ulnar length; robust, tapering to the distal end, very gently caudally deflected. Proximomedial flexor fossa moderately concave. Facet for humeral articulation large, quite shallow, with the trochlear notch present as a gently rounded medial ridge; medial component particularly large; anconeal process with a deeply obtuse angle, narrower than the combined coronoid process and radial facet; coronoid process large, rounded in proximal view, projected cranially and slightly laterally.Radialfacetcrescenticinjuvenilestosemicircular in adults, proximodistally short, broad. Ulnar tuberosity small, narrow and rugose. Shaft curves gently cranially in its proximal component, straightens distally; height tapers slightly distally in lateral view; cranial margin of the midpoint to the distal component marked by a ridge that arises on the dorsolateral margin (interosseous border with the radius, and the cranial margin of the origin of m. flexor digitorum profundus ulnaris) and extends distally and slightly medially to the medial margin of the distal epiphysis; a low ridge extends from the medial margin of the ulnar tuberosity, along the dorsomedial margin of the shaft and onto the medial surface of the distal component. Distal epiphysis robust, circular in distal view; styloid process robust, rounded and cranially deflected.
The ulna of P. mamkurra sp. nov. differs from all compared taxa in its greater robustness when adult, particularly of the distal shaft. It further differs P. anak in being shorter, with a lesser degree of recurve in lateral view, and a more transversely compressed distal shaft in cross-section; from P. viator sp. nov. in being generally shorter; from P.tumbuna in being larger; from P. otibandus in its broader olecranon; from C. kitcheneri in being deeper, straighter in cranial view, with a less cranially deflected olecranon, more medially flared coronoid process, less rounded radial facet, and the distal shaft less cranially curved; from O. rufus in being deeper, with a less cranially deflected olecranon, broader and less laterally tilted lateral component of humeral facet, less bilobed lateral margin of humeral facet, more anteriorly situated, less laterally tilted radial facet, and much less tapering of the distal shaft; from M. fuliginosus in being larger and deeper, with a less medially flared coronoid process, less bilobed lateral margin of humeral facet and more distally projected styloid process; and from W. bicolor in being larger and deeper, with a less cranially deflected and projected olecranon, less medially flared coronoid and anconeal processes, and a shallower humeral facet.
Radius (Fig. 46h–j): robust with slight to strong curvature. Radial head circular to slightly oval. Radial neck slightly flattened proximal to the radial tubercule. Radial tubercule rugose, oval and smoothly, gently projected. Shaft cross-section circular to rounded-triangular immediately distal to the radial tubercle; very craniocaudally compressed in the middle to distal shaft. Cranial ridge thick and low or absent, arises closer to the midpoint of the shaft than to the radial tubercle. Caudal ridge thin, extends across the midpoint of the shaft (Fig. 46j); more raised, elongate and distinct in larger specimens. Distal end teardrop-shaped to roughly triangular in distal view; scaphoidal facet broad and slightly concave; styloid process quite robust, caudomedially situated and slightly curved caudolaterally.Ulnar notch broad, quite shallow and elongate; deeper and more elongate in older individuals.
The radius of P. mamkurra sp. nov. differs from that of P. anak in being shorter, more robust, and generally more curved, with greater craniocaudal compression of the distal shaft and a more flattened caudomedial surface of the distal shaft; from P. viator sp. nov. in being shorter, more robust, and generally more curved, with a more distally situated cranial ridge, more raised and distinct caudal ridge, and a more craniocaudally compressed distal shaft; from P. tumbuna in having a more craniocaudally compressed distal shaft and a more caudolaterally curved and caudally situated styloid process; from P. otibandus in being more robust, with a lower cranial ridge, shallower proximal shaft, and a more craniocaudally compressed distal shaft; from C. kitcheneri in being generally larger, typically with a lower, less proximally extensive caudal ridge and the scaphoidal facet not tilted cranially; from O. rufus in being shorter and more robust, with a slightly greater degree of the shaft curvature and a more raised caudal ridge; from M. fuliginosus in being larger and more robust, with greater craniocaudal compression of the distal shaft and a deeper, broader and more distinct ulnar notch; and from W. bicolor in being larger and more robust, with a lower caudal ridge and a more triangular distal shaft in cross-section.
Manus
Scaphoid (Fig. 47a–h): broad and robust, roughly semicircular in dorsal view. Palmar process dorsopalmarly compressed and medially projected. Radial facet broad, rounded and smoothly convex, extends from the posteropalmar margin over most of the dorsoposterior surface of the body of the scaphoid; ridge for articulation with the styloid process of the radius is thick and dorsally raised (Fig. 47g). Facet for the hamatum gently convex, continuous medially with the large, concave facet for the capitatum. Facet for the trapezoid small, dorsopalmarly compressed, situated mesially on the anterodorsal margin. Facet for the trapezium broad, strongly convex, situated on the anterior surface of a rounded and highly dorsopalmarly compressed medial projection. A broad, shallow fossa is present on the palmar surface of the base of the palmar process, anteropalmar to the medial margin of the radial facet.
The scaphoid of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in having a narrower palmar process and the facets for the hamatum and the capitatum less distinct from each other, with a thickened, raised dorsal ridge present for the styloid process of the radius and a broader facet for the trapezoid; from P. otibandus in having the palmar process less palmarly drooped and more anteriorly deflected; from C. kitcheneri in being broader, with a broader and more anteropalmarly deflected palmar process, the hamatal and trapezoidal facets more distinct, and the hamatal facet convex instead of concave; from O. rufus in being broader, with a larger palmomedial fossa; from M. fuliginosus in being larger, with a shorter, rounder and less craniocaudally compressed medial component and a deeper palmomedial fossa; and from W. bicolor in being much larger, with a deeper, more transversely compressed and much less palmarly curved palmar process.
Triquetrum (cuneiform) (Fig. 47i–n): roughly two-thirds the size of the hamatum, anteroposteriorly compressed, roughly oval in posterior view, with a convex dorsal surface (Fig. 47m). Facet for the ulnar styloid process round, and smoothly, moderately concave. Facet for the pisiform half the size of the styloid facet, roughly triangular in posterior view, and gently concave, with a small, shallow lateral fossa.A tubercle on the posteropalmar surface projects posteriorly beneath the styloid facet and the pisiform facet. Facet for the hamatum broader than it is tall, with a smoothly convex lateral component, a gently concave medial component, and a slightly convex centre.A small foramen is present beneath the lateral component of the hamatal facet. The posterior and anterior margins of the dorsal surface are dorsally flared, increasingly so laterally.
The triquetrum of P. mamkurra sp. nov. differs from that of P. otibandus in having a more convex dorsal surface and a slightly larger pisiform facet; from C. kitcheneri in being larger and relatively slightly broader, with a larger pisiform facet and a more convex lateral component of the hamatal facet; from O. rufus in being larger, with a taller, more deeply concave pisiform facet, a larger posteropalmar tubercle, and a broader hamatal facet; from M. fuliginosus in being larger, taller, relatively narrower, and lacking a pointed medial projection; and from W. bicolor in being much larger, with the pisiform facet more deeply concave, more posterior facing and less laterally rotated, and the hamatal facet broader and more smoothly convex on the lateral component.
Hamatum(Fig.48a–f):tall,broad,andanteroposteriorly quite short. The posteromedial component is tall, narrow, squarish, and projected. Facet for the triquetrum large, broad, gently dorsally tilted, and occupying the posterior surface with a slight extension onto the base of the posterior of the palmar process; anterior component tall, transversely concave, and posterior facing, with a convex dorsal margin; posterior component of triquetral facet shorter, gently convex and posterolaterally facing, situated on the posteromedial projection of the hamatum. Facet for the scaphoid flat and indistinct, situated on the posteromedial surface and abutting the medial margin of the triquetral facet and the lateral margin of the capitatal facet. Facet for the capitatum continuous with the facet for the lateral surface of the posterior end of metacarpal III; gently and smoothly concave, curving over a very small, shallow foramen; semicontinuous posteriorly with the scaphoidal facet, meeting at a sharp corner. Facet for metacarpal IV squared and smoothly concave; almost indistinct from the facet for metacarpal V. Facet for metacarpal V concave, covering the craniodorsal surface of the palmar process. Palmar process large, tall, anteroposteriorly flattened, projecting palmarly and tilted strongly anterolaterally with a slight lateral rotation (Fig. 48e).
The hamatum of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in being shallower, with a less concave scaphoidal facet, broader combined metacarpal IV and V facets relative to the capitatal and metacarpal III facets, a larger, taller and anterolaterally projected (rather than posteropalmarly projected) palmar process, and a concave (rather than convex) metacarpal V facet; from P. otibandus in being larger and shallower, with the facet for the triquetrum more extensive medially to be semicontinuous with (rather than distinctly separate from) the facet for the scaphoid, and the palmar process larger, taller and anterolaterally projected (rather than posteropalmarly projected); from C. kitcheneri in being larger, taller and more robust, with a more dorsally curved triquetral facet for metacarpal IV, a smaller facet for metacarpal V, and the palmar process anteroposteriorly deeper, less projected and less anteriorly deflected; from O. rufus in being larger and deeper, with a taller posteromedial component, less concave scaphoidal facet, and a broader and smoother metacarpal IV facet; from M. fuliginosus in being larger, with a relatively much taller anterior component of the triquetral facet, semicontinuous (rather than distinct) hamatal and metacarpal III facets, and a larger, narrower palmar process; and from W. bicolor in being much larger, with a flatter scaphoidal facet, semicontinuous hamatal and metacarpal III facets, and a relatively larger facet for metacarpal III.
Capitatum (Fig. 49): triangular to roughly oblong in dorsal view, with the palmar surface roughly triangular due to narrowing of the process on the posteropalmar margin. Facet for the hamatum rounded-triangular, smoothly and gently convex, pointed posteriorly, occupies the posterolateral surface, with a small, rounded fossa against the dorsoposterior margin. Facet for the scaphoid posteriorly flat, becomes taller and slightly concave anteriorly; covers posteromedial surface, posteriorly semicontinuous with hamatal facet. Facet for metacarpal III large, covers the anterior surface, subdivided into a semicontinuous smaller medial component and a larger lateral component for the medial and lateral processes of the posterior end of metacarpal III; both gently concave with a narrow, gently convex medial margin. A shallow, broad, oblong fossa is present beneath the metacarpal III facet on the anterior surface. The anteromedial surface is anteroposteriorly short, with a tall, concave facet for the medial component of the posterior facet of metacarpal II occupying the anterior component. Facet for the trapezium narrow and flat, on posteropalmar component of medial surface. Two fairly large, rounded, linked tubercles are situated against the anterior margin of palmar surface.
The capitatum of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in being anteroposteriorly shorter with a smaller palmar process, and in having a small fossa present on the dorsoposterior surface (Fig. 49f) and a larger fossa present on the anterior surface beneath the metacarpal III facet (Fig. 49g); from P. otibandus in being larger with a blunt palmar process; from C. kitcheneri in being larger and less deep, with a taller medial component of the metacarpal III facet and a taller, narrower and more medially situated facet for metacarpal II; from O. rufus in being larger, with a taller facet for the trapezoid and a small dorsoposterior fossa; from M. fuliginosus in being larger and broader, with a taller facet for the trapezoid and a flatter metacarpal III facet; and from W. bicolor in being much larger, with a larger, more convex facet for the hamatum.
Trapezium (Fig. 48g –j): articulates with the dorsoanterior surface of the palmar process of the scaphoid. Broad and roughly rounded in anterior view, with a large, pointed eminence against the lateral margin on the anterodorsal surface for articulation with the anteromedial surface of the trapezoid and with the dorsal component of the posterior surface of metacarpal I. The anteromedial component is broadly rounded. Facet for the scaphoid broad, and smoothly, deeply concave. Facet for metacarpal I has a larger, rounded medial component that continues laterally into a smaller, gently convex dorsolateral component on the pointed anterolateral eminence.
The trapezium of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in being slightly broader, with a more rounded medial margin; from C. kitcheneri in having a more concave facet for the palmar process of the scaphoid; from O. rufus and M. fuliginosus in being larger relative to the trapezoid, with a more pointed anterolateral eminence, and a more distinct facet for metacarpal I with more distinct medial and lateral components; and from W. bicolor in being both absolutely larger and larger relative to trapezoid, with a more deeply and smoothly concave facet for the palmar process, and a broader, more distinct facet for metacarpal I.
Metacarpals I–IV (Fig. 50a–d): short and robust, with the shaft and distal end slightly dorsopalmarly compressed and the proximal surfaces dorsally tilted, particularly metacarpals III and IV (Fig. 50a). Metacarpal I: extremely short and robust, with a broad, thickened proximal end and an asymmetrical distal end. Metacarpal II: elongate relative to the other metacarpals; proximal end narrow, with a tall, narrow facet for the capitatum abutting the lateral margin of the smaller, broader facet for the trapezium and trapezoid.Distal end strongly asymmetrical, with the lateral component enlarged. Metacarpal III: proximal end broad and dorsopalmarly quite tall with the palmar component abraded. Shaft proximally narrow, steadily broadens to a broad distal end. Distal end with an enlarged keel. Metacarpal IV: proximal end enlarged, with the proximal facet for the hamatum large, flat, tilted slightly dorsally, roughly triangular in proximal view, and laterally projected in dorsal view. Medial facet for metacarpal III tall and narrow. Lateral facet for metacarpal V relatively broader, gently concave and angled anteriorly. Shaft narrows to a waist quite close to the proximal end, broadens and deepens steadily distally. Distal end broad.
The metacarpals of P. mamkurra sp. nov. do not differ from those of P. anak. They differ from those of P. viator in being shorter and more robust, with the narrowest point of the shaft closer to the proximal end; from P. otibandus in being larger and more robust; from C. kitcheneri in being slightly more gracile, with a narrower proximal shaft, squarer and less convex distal end, and a squarer and more projected proximolateral process of metacarpal III; from O. rufus in being larger; from M. fuliginosus in being larger and much more robust; and from W. bicolor in being larger and much more robust, with more dorsally tilted proximal surfaces.
Manual phalanges (Fig. 50f–h): proximal phalanges: short, broad, robust and dorsopalmarly compressed, with the proximal articular facet tilted distinctly dorsally. Distal end with a moderately shallow, slightly V-shaped trochlea. Middle phalanges: very short, broad and dorsopalmarly compressed,withaslightlydorsallytiltedproximalarticular surface. Distal end broad with a very shallowly concave trochlea. Distal phalanges: elongate, with a smoothly concave proximal articular surface. Palmar tubercles small and weakly palmarly projected. Shaft spatulate, straight to slightly palmarly curved, and extremely dorsopalmarly compressed, with a gently convex dorsal surface.
The manual phalanges of P. mamkurra sp. nov. differ from those of P. anak in having proximal phalanges with a slightly shallower trochlea and distal phalanges with a longer, more dorsopalmarly compressed shaft; from P. viator sp. nov. in being generally slightly longer, particularly the distal phalanges, which have a flatter palmar surface and lack a slight dorsal peak; from P. otibandus in having much shorter, broader shafts, greater degree of dorsopalmar compression and palmarly uncurved distal shafts; from C. kitcheneri in being smaller relative to metacarpals, relatively broader and far more dorsopalmarly compressed, particularly middle and distal phalanges, with the proximal surface of the proximal phalanges more dorsally tilted, trochleae broader and less V-shaped, and the distal phalanges dorsally rounded and un-peaked with less palmar curvature of the shaft; from O. rufus in being relatively broader, with the distal phalanges longer,more dorsopalmarly compressed and more palmarly curved; from M. fuliginosus in being larger, much broader and more robust, with proximal phalanges with shallower trochlea and less projected, more gently rounded proximal flexor tubercules, and distal phalanges with the shaft far less curved palmarly and very slightly rounded dorsally (rather than sharply peaked); and from W. bicolor in being larger, more dorsopalmarly compressed and more robust, with slightly more dorsally tilted proximal surfaces on the proximal and middle phalanges.
Hindlimb
Pelvis (Fig. 51): ilium: robust, well-developed and roughly L-shaped in cross-section. Epiphysis of iliac crest not known; iliac crest thick and broad, aligned transversely; width gently increases to maximum at the iliac crest. Iliac fossa shallow, extends one-third of the length of the ischium in juveniles; deeper, more concave and extends distally three-quarters of the length of the ilium in adults. Gluteal fossa broad, deeply concave, narrows distally, extends to the iliac crest. Caudal iliac spine (tuber sacrale) arises rapidly on the caudal surface of the base of the ilium, opposite the rectus tubercule; thick and tall proximally for origin of a large mm. gluteus, becomes thinner and slightly lower distally, extends to the iliac crest. Sacral surface (articular surface for wings of sacrum) deep, thickened and craniocaudally aligned with a slight cranial tilt, surrounded by a rugose surface, abuts the caudoventral margin of the medial surface of the caudal iliac spine, projects cranially as a low ridge with a thin crest that forms the cranial iliac spine and contributes to depth of iliac fossa; extends to the cranioventral margin in older specimens. Lateral iliac spine broad, slightly thinner than the caudal spine, with the lateral margin gently concave and curved slightly laterally to the projected dorsolateral extremity of the iliac crest. Rectus tubercule large, rugose, roughly triangular, and gently narrowing cranially onto the lateral iliac spine; increases in relative size with age. Acetabulum large, tall and deeply concave, deepest in the ventral component; taller than craniocaudal depth; acetabular fossa deep, partially covered cranially and caudally by a lip that projects from the acetabular surface, and with the angle, width and curvature variable within individuals.
Ischium: very deep, transversely compressed, gently concave medially and convex laterally; caudal margin rugose and gently undulating from the origin of mm. gemelli; deflected slightly caudally relative to the axis of the ilium; caudal component thickens toward the ventral margin and curves slightly caudolaterally to the large, laterally projected ischiatic tuberosity. Iliopubic (iliopectineal) eminence slightly projected, rounded, broad and rugose. Caudomedial surface of the ischium with a broad, smoothly concave coccygeal fossa for the origin of a large m. coccygeus. The craniodorsal angle of the obturator foramen is acute and rounded.
Pubis: narrows ventral to the iliopubic eminence, broadens ventromedially and becomes transversely thinner toward the pubic tubercle; pubis thickening at the ilial junction with age; planar at the pubic symphysis, thins caudoventrally before thickening to the ischiatic symphysis. Pubic tubercle (area of articulation for the epipubic) is abraded, interpreted as being raised and slightly rugose. Ischiatic table tall and planar, thickens toward the robust ischiatic arch.
The pelvis of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in having a slightly less broad lateral iliac spine and a more elongate rectus tubercle; from P. tumbuna in having its acetabulum opening more laterally and less cranioventrally, with a more deeply concave ventral component, larger iliopubic eminence, and a narrower, more planar ischium that is slightly longer relative to the ilium and is more caudally deflected relative to the axis of the ilium in lateral view; from P. dawsonae sp. nov. in being generally larger, with a larger caudal iliac spine, deeper gluteal fossa, less cranially tilted articular surface for the wings of the sacrum, less laterally projected rectus tubercle, more deeply concave acetabulum, and a more convex and rugose caudal margin of the craniodorsal component of the ischium; from C. kitcheneri in being larger, with a far broader and deeper gluteal fossa, narrower and less distally extensive iliac fossa, more caudally and dorsally situated sacral surface relative to the acetabulum, and a rounder and shallower acetabulum; from O. rufus and M. fuliginosus in being larger and more robust, with a far broader and deeper gluteal fossa, less distally extensive iliac fossa, broader lateral iliac spine, and greater maximum acetabulum diameter relative to the ilial length; and from W. bicolor in being far larger, with the iliac crest aligned more transversely and less craniocaudally, a broader and deeper gluteal fossa, a narrower and less distally extensive iliac fossa, a broader lateral iliac spine, particularly dorsally, the caudal iliac spine lacking a small, pointed eminence on the caudoventral shoulder, the rectus tubercle with a smaller, shallower fossa on the lateral surface, more deeply concave ventral component of the acetabulum, a more robust pubis where it abuts the acetabulum, and a higher, more distinct dorsoventral ridge that leads to the lateral surface of the ischiatic tubercle.
Femur (Figs 52 & 53h): large and elongate, with the shaft straight in dorsal and lateral views. Head large, hemispherical, dorsomedially projected, and gently flared dorsally. Proximal end very broad, with a smoothly, distinctly convex dorsal surface. Intertrochanteric crest low, curving from the ventromedial base of the greater trochanter to the lesser trochanter. The greater trochanter is not known. Greater trochanteric ridge broad, thick, slightly ventrally arched, and slightly laterally projected to form a low, rugose proximolateral ridge on the dorsolateral margin of the proximal end (Fig. 52a); proximolateral ridge is slightly more raised and distally extensive in older specimens. Trochanteric fossa extends distally to level with the lesser trochanter. Lesser trochanter is present as a moderately medially projected rugose eminence, remains an unfused epiphysis until well into adulthood; merges distally into the thick, raised, medially orientated lesser trochanteric ridge (point of insertion for an enlarged m. iliopsoas) on the ventromedial surface of the shaft, which becomes more medially projected distally.
Quadratus tubercule raised, oval and situated on the proximodistal midpoint of the ventral surface of the shaft, narrows and extends proximally to level with lesser trochanter. Shaft broadens from midpoint toward the distal end, becomes flatter on the ventral surface. An elongate fossa is present on the caudolateral shaft adjacent to the ventrolateral margin of the distal epiphysis, roughly triangular in ventral view and narrows proximally; the partial origin of the m. flexor digitorum superficialis.
Femur distal epiphysis broad and robust. Lateral trochlear crest broad and rounded, taller than the slightly narrower medial crest. Intercondylar fossa broad, rounded; broadest at midpoint, narrows dorsally. Lateral condyle broad, with the ventral surface gently convex. Trochlea shallow and broad. Fibular facet on the lateral condyle slightly ventrally deflected and distinctly laterally projected. Medial condyle with the distal and ventral surfaces convex in juveniles, roughly planar with rounded margins in adults. Lateral epicondyle has the ventral component projected ventrolaterally such that the lateral surface is distinctly sloped; a shallow and rugose fossa is present around the midpoint of the lateral surface, and a moderately deep fossa is present on the ventral margin and is angled slightly distally, both points of origin of the m. gastrocnemius lateralis. Medial epicondyle gently dorsally tilted, with the ventral component moderately projected and bulged; medial gastrocnemial fossa shallow, rounded, rugose, situated on the centre of the medial surface.
The femur of P. mamkurra sp. nov. differs from that of P. anak in being slightly more robust, with a less dorsally deflected head, weaker proximolateral ridge and deeper trochlea, and the trochlear crests subequally raised (rather than the lateral crest being more raised); from P. viator in being longer and more gracile, with a lower, less distinct intertrochanteric crest, less medially projected lesser trochanter, weaker proximolateral ridge, relatively shorter lesser trochanteric ridge, broader and shallower trochlea, more rounded trochlear crests with a relatively broader medial trochlear crest, and a more medially projected ventral component of the medial epicondyle; from P. tumbuna in being larger and more robust, with a less elongate and more proximally situated quadratus tubercle; from P. otibandus in being larger, with the trochlea broader and shallower, and the medial condyle relatively broader; from C. kitcheneri in having a narrower shaft relative to length, a relatively large femoral head, more distally extensive trochanteric ridge and ventromedial ridge, straighter shaft in dorsal view, lack of distinct anti-clockwise rotation of the distal epiphysis in distal view, less reduced medial trochlear crest relative to lateral crest in distal view, broader intercondylar fossa, and a smaller, less ventrally projected lateral epicondyle; from O. rufus and M. fuliginosus in being generally larger and more robust, with a relatively larger proximal end, more laterally displaced trochanteric ridge and trochanteric fossa such that the ventral face of the proximal end is relatively broader, a more distally extensive lesser trochanteric ridge, more elongate and more distally situated quadratus tubercle, relatively broad distal end, less raised lateral trochlear crest, less pointed medial trochlear crest, shallower trochlea, and a more proximally situated lateral gastrocnemial fossa; and from W. bicolor in being larger and more robust, with a relatively larger and more dorsally deflected head, less distally extensive trochanteric fossa relative to the head, more distally extensive lesser trochanteric ridge, less proximally situated quadratus tubercle, less dorsoventrally compressed distal shaft, relatively lower, broader distal condyles, shallower trochlea, larger fibular facet on the lateral condyle, and a more proximally situated lateral gastrocnemial fossa.
Tibia (Fig. 53a–d, h): short and robust, with the proximal shaft bowed gently medially and the distal shaft bowed gently laterally in cranial view. Proximal epiphysis width subequal to its depth (cranial component of the epiphysis not preserved in available specimens; size based on the depth of the proximal tibia of holotype). Medial condyle medially and caudally rounded, deeper and slightly narrower than the lateral condyle. Lateral condyle comes to rounded points at the lateral and caudal margins, with a moderately deep groove in the craniolateral margin. Intercondylar eminence low and broad. Proximal fibular facet narrow, deep, shelf-like, and orientated ~40° laterally from the sagittal plane. Cnemial crest deep, thickened and elongate, extends ~25% of the total tibial length, with the lateral surface moderately concave and the medial surface moderately convex. Proximolateral crest thin and raised, becomes thinner and more raised distally before merging smoothly with the shaft distal to the midpoint of the tibia. Distal component of the shaft briefly narrows to a minimum before expanding smoothly to the distal end in all axes, but particularly craniomedially, with a slight medial deflection; minimum shaft circumference is at ~three-quarters of length. Distal fibular facet extends for the distal two-fifths of the lateral surface of the tibial shaft. Distal epiphysis large and broad; medial tuberosity thick and robust, with a blunt medial malleolus; talar trochlea broadly concave with rounded cranial and caudal ventral eminences.
The tibia of P. mamkurra sp. nov. differs from that of P. anak in being shorter and more robust, with a thicker proximal component of the proximolateral crest; from P. viator sp. nov. in being shorter and much more robust, and in having a more laterally curved cnemial crest in cranial view with less angular and distinct distal peak, a thicker proximal component of proximolateral crest, and a slightly more medially deflected distal component of the shaft; from P. tumbuna in being longer and more gracile, with a less elongate cnemial crest relative to the total length, thinner proximolateral crest, and a narrower and less flattened distal fibular facet; from P. otibandus in being larger, with a smaller and narrower proximal fibular facet and a deeper, more elongate cnemial crest; from P. snewini in being shorter and much more robust, with a less angular and distinct distal peak of the cnemial crest, thicker proximal component of proximolateral crest, and a far shorter distal shaft relative to the proximal component; from C. kitcheneri in being larger and more robust, with a lower, broader intercondylar eminence, less deeply concave muscular groove on the proximal epiphysis, more distally extensive proximolateral crest, and a relatively deeper distal component of the shaft with greater expansion to the distal epiphysis; from M. fuliginosus and O. rufus in being far shorter and more robust, with a lower, broader intercondylar eminence, broader proximal epiphysis with a deeper muscular groove, a more concave cnemial crest on the lateral surface, and a greater degree of expansion of the distal shaft toward the epiphysis; and from W. bicolor in being larger and more robust, with a broader proximal fibular facet, thicker proximolateral crest, less angular cnemial crest peak, and a more rounded talar trochlea.
Fibula (Fig. 53e–g): proximal epiphysis large, with a broad facet for tibia, and a tall, thickened caudal process for articulation with the fibular facet on the lateral epicondyle of the femur. Shaft with the proximal component thick and roughly triangular in cross-section, with a broad, rounded groove on the craniolateral surface for the major origin of a large m. extensor digitalis IV; shaft transitions to tear-drop shaped in cross-section before flattening around its midpoint; distal component is crescentic in cross-section and very deep in the craniocaudal plane, with the lateral surface convex and the medial surface concave; deepens briefly distally, shallows to a waist and deepens to maximum at distal end; shallow proximodistally aligned groove on lateral surface of distal end. The distal epiphysis is not known.
The fibula of P. mamkurra sp. nov. differs from that of P. anak in being more robust; from P. viator sp. nov. in being shorter, with less broadening and shallowing of the section of the shaft immediately proximal to the distal epiphysis; from C. kitcheneri in its relatively larger proximal epiphysis and relatively deeper distal shaft; from O. rufus in being shorter and much more robust, with broader proximal end, deeper groove for m. extensor digitalis IV and deeper distal component of the shaft; from M. fuliginosus in its much greater robustness, more thickened, raised proximomedial ridge, and more triangular proximal shaft in cross-section; and from W. bicolor in being larger and more robust, with relatively larger proximal epiphysis.
Pes
Calcaneus (Figs 53h & 54a–f): large, broad and very robust. Calcaneal tuberosity tall and domed, narrowing only slightly cranially in dorsal view, and dorsally rounded in cross-section. Caudal surface tall and domed in caudal view; two small, semicontinuous transverse valleys, occasionally continuous as single broad valley, extend across the bottom half. Plantar surface rugose, subrectangular in plantar view, becomes thicker, broader and more rugose with age; cranial section narrows slightly cranially and extends to level with the cranial margin of the sustentaculum tali; caudal component slightly thicker, consists of the caudal epiphysis wrapping cranioplantarly under the tuberosity. Cranial plantar tubercule distinct, rounded, immediately craniomedial to the craniomedial margin of the plantar surface. Sustentaculum tali large, tall, deep, medially projected beyond medial margin of talar facet; tapers to a pointed, cranioplantar peak (Fig. 54c); caudal margin gently convex in medial view; becomes more projected, more rugose and slightly more extensive caudally with age. Flexor groove very broad and deep.
Fibular facet very large, bulbous, tapers medially; caudal part large, roughly oval, and dorsolaterally projected, with an indistinct medial margin (Fig. 54a & f); cranial part low, and elongated toward the lateral margin of the dorsolateral cuboid facet. Lateral talar facet large, strongly convex and semi-cylindrical, semi-fused with the medial talar facet but with contours distinct; a small, rounded fossa, for articulation with the plantar process of the craniolateral margin of the talus, abuts the craniolateral margin of this facet. Medial talar facet large, oval, flat to slightly concave and cranially inclined, craniocaudally level with the lateral talar facet; articular surface extends onto the caudal face to form a convex, rounded lip. A small, rounded, variably deep, caudal-facing fossa extends beneath the lateral component of the caudal margin of the medial facet.
A small facet abuts the medial margin of the dorsomedial facet on the medial surface of the calcaneal head for articulation with the talar head. Dorsomedial cuboid facet broad, roughly pentagonal in cranial view, and gently convex; lateral margin ‘stepped’ to dorsolateral facet, as in P. anak; a deep, subrectangular to oval fossa is situated immediately plantarly. Dorsolateral cuboid facet tall, cranially projected, tilted plantarly and slightly medially, convex in lateral view, tapers plantarly and curves medially to be continuous with the plantomedial facet; dorsal margin angled plantolaterally or with a distinct step on the medial component of the dorsal margin; the rounded lateral margin curves plantomedially to the plantomedial facet. Plantomedial cuboid facet quite small, oval, short and broad.
The calcaneus of P. mamkurra sp. nov. differs from all compared taxa in having a sustentaculum tali with a pointed cranioplantar peak, and craniocaudally level and semicontinuous medial and lateral talar facets (Fig. 54a). It further differs from that of P. anak in being generally more robust, with a less rounded caudal fibular facet with less distinct margins, and more bulbous, dorsally projected medial talar and fibular facets; from P. viator sp. nov. in being lower, considerably broader, and more robust, with larger, more bulbous talar facets, a larger, more bulbous fibular facet with a more rounded and caudally projected (rather than laterally projected) caudal part, and a more medially projected sustentaculum tali; from P. tumbuna in being larger and taller, with a larger medial talar facet, relatively narrower and more convex medial cuboid facet, and a planar, less medially flared plantar surface; from P. dawsonae sp. nov. in being larger, taller and more robust, with more bulbous lateral talar and caudal fibular facets, and fibular facet with a more plantarly extensive lateral part in lateral view; from P. otibandus in being larger, with a relatively taller calcaneal tuberosity, less medially displaced calcaneal head, and a relatively larger, more caudally projected caudal part of the fibular facet; from C. kitcheneri in being larger, taller and more robust, with a larger, more rounded caudal part of fibular facet that lacks a thin, laterally flared lateral margin, larger and more bulbous talar facets, more cranially extensive and less laterally tilted plantar surface, and a broader plantomedial cuboid facet; from O. rufus and M. fuliginosus in being larger, much broader and more robust, with a broadly rounded, domed calcaneal tuberosity in cross-section (rather than narrow and peaked), more medially projected sustentaculum tali, a larger, more convex, more dorsally swollen and more caudally extensive fibular facet, a more bevelled ‘step’ between the dorsal cuboid facets, a broader dorsolateral cuboid facet, and a narrower dorsomedial cuboid facet; and from W. bicolor in being much larger, relatively broader and more robust, with a larger, more bulbous fibular facet and lateral talar facet, and a larger, relatively broader, and less cranially tilted medial talar facet with a rounded caudal lip.
Talus (Fig. 54g –i): robust and considerably width greater than length. Trochlear crests rounded, subequal in height and breadth, orientated in the sagittal plane.Trochlea quitedeepandsmoothlyconcave.Medialmalleolusextends medially and slightly cranially, bounded craniolaterally by a broad, very shallow malleolar fossa. Talar head broad, tall in lateral view, projected craniolaterally, and plantarly deflected. Facet for the cuboid distinct, flat, roughly triangular, facing craniolaterally on the lateral surface of the head. Navicular facet large and tall, extends medially and caudoplantarly from the cranial surface of the talar head to its caudoplantar extent, plantar to the medial malleolus (Fig. 54h–i). Posterior plantar process large, thick, rugose, and plantarly projected; comes to a rounded point in medial view. In plantar aspect, the medial calcaneal facet is broad and rounded, with a large, planar, caudal-facing cranial part curving to meet a smaller, concave caudal part; lateral calcaneal facet is broad, deeply concave, roughly cylindrical, and tapers medially.
The talus of P. mamkurra sp. nov. differs from that of P. anak and P. viator sp. nov. in being relatively broader, and having a deeper trochlea with a less medially skewed concavity, more plantarly projected talar head, more medially aligned and projected medial malleolus, and a larger, more medially extensive navicular facet; from P. otibandus in being larger, with a broader, shallower malleolar fossa, slightly more plantomedially extensive navicular facet, and a deeper plantar concavity that separates the talar head from the posterior plantar process; from P. snewini in being larger and relatively broader, with a more deeply concave trochlea, more medially projected medial malleolus and talar head, larger cuboid facet on talar head, broader and more caudoplantarly extensive navicular facet, and a larger notch between the cranial margin of medial trochlear crest and the talar head; from C. kitcheneri in being larger, with a cuboid facet present on the talar head and a broader, medially deflected, and more caudoplantarly extensive navicular facet; from O. rufus and M. fuliginosus in being larger and relatively broader, with the trochlear crests more even in height, the trochlea deeper and a broader, more plantar facing, medially deflected and caudoplantarly extensive navicular facet; and from W. bicolor in being much larger and relatively broader, with a less medially skewed trochlear concavity, larger cuboid facet, more plantomedially extensive navicular facet, shallower malleolar facet, more transversely aligned medial malleolus, and a more rounded posterior plantar process in medial view.
Cuboid (Fig. 55a–c): large, broad and roughly rectangular in dorsal view except for ‘stepped’ calcaneal facet. Dorsomedial calcaneal facet caudally projected, slightly broader and dorsoplantarly shorter than dorsolateral facet. Dorsolateral calcaneal facet tall and plantomedially continuous, with a short, rounded plantomedial calcaneal facet. Facet for articulation with the talar head quite small, roughly triangular, and slightly concave, abuts the dorsomedial calcaneal facet on the craniodorsal margin of the medial surface. Metatarsal IV facet very large, slightly concave, with the medial part of the dorsal margin gently convex. Metatarsal V facet large, very broad and oval (Fig. 55b), dorsoplantarly short, laterally projected, slightly concave and slightly laterally tilted; incompletely separated from the metatarsal IV facet. Lateral plantar tubercle very broad, craniocaudally compressed (Fig. 55a); extends laterally and slightly caudally over caudoplantar part of the lateral surface. Medial plantar tubercle partially abraded in available specimens; small, plantomedially projected and quite elongate; small relative to lateral plantar tubercle, separated by a broad, moderately shallow flexor groove. The area of articulation with the navicular on the dorsocaudal part of the medial surface is rugose, and wraps cranially around the facet for the talar head. Facet for the ectocuneiform indistinct, tall, craniocaudally very short, with semicontinuous dorsal and plantar sections; dorsal component abuts the medial margin of the metatarsal IV facet on the cranial margin of the medial surface; plantar component extends plantarly, along the medial margin of the plantar cuboid facet, onto the base of the medial surface of the medial plantar tubercle.
The cuboid of P. mamkurra sp. nov. differs from that of all compared taxa in having a broader metatarsal V facet and from all taxa except W. bicolor in having a broader flexor groove. It further differs from P. anak in having a deeper, more distinct talar facet, less plantarly projected lateral plantar tubercle, and a shallower flexor groove; from P. viator sp. nov. in being broader relative to height, with a shallower, less plantarly projected lateral plantar tubercle, less plantarly projected, slightly more medially situated medial plantar tubercle, and a shallower flexor groove; from P. otibandus in being larger, with a less dorsally flared dorsomedial margin, more distinct step between dorsal calcaneal facets, broader dorsolateral calcaneal facet, larger and more distinct talar facet, shallower medial fossa for navicular and ectocuneiform, less plantarly projected lateral plantar tubercle, dorsal metatarsal IV facet continuous with the plantar facet, and a less concave metatarsal V facet; from P. snewini in being larger and broader, with a less dorsally flared dorsomedial margin, relatively broader dorsolateral calcaneal facet, shallower medial fossa for the navicular and ectocuneiform, and a larger, more plantarly projected and more medially situated medial plantar tubercle; from C. kitcheneri in being larger, taller and broader relative to depth, with a facet for the talar head present, a larger and more caudally extensive medial plantar tubercle, and a deeper flexor groove; from O. rufus in being larger, broader and relatively dorsoplantarly shorter, with a broader, less inset dorsolateral calcaneal facet, more medial facing facet for the talar head, broader and less plantarly projected lateral plantar tubercle, larger, more medially situated projected medial plantar tubercle, and a more medially situated plantar metatarsal IV facet; from M. fuliginosus in being larger, relatively broader, and squarer in outline in caudal view, with a much less plantarly projected, more dorsolaterally extensive lateral plantar tubercle, larger, more projected medial plantar tubercle, and a more medially extensive plantomedial calcaneal facet; and from W. bicolor in being much larger and relatively broader, with a broader dorsolateral calcaneal facet relative to the dorsomedial facet, larger step between dorsomedial and dorsolateral calcaneal facets, broader and less plantarly projected lateral plantar tubercle, and a larger medial plantar tubercle.
Navicular (Fig. 55d–k): tall, narrow and quite deep, tapering slightly in width dorsally; cranial margin slightly taller than the caudal margin. Facet for the talar head smoothly concave, with the plantar part broad, rounded and tilted dorsally. Facet for the cuboid situated on the lateral surface, semicontinuous with the dorsal component of the lateral margin of the talar facet. Facet for the entocuneiform small, oval, transversely compressed and tilted slightly plantarly; situated against the plantomedial margin of the cranial surface. Dorsal facet for the ectocuneiform large, tall, fairly narrow and gently convex, extends from the dorsal margin of the cranial surface to level with the facet for the entocuneiform; plantar facet for the ectocuneiform is very small, rounded, convex and situated on the cranioplantar surface against the medial margin; lateral and slightly plantar to the entocuneiform facet, completely separate from the dorsal facet.
The navicular of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in being broader, with a less plantarly extensive dorsal ectocuneiform facet; from P. otibandus in being larger, and deeper relative to height, with a less laterally flared dorsal ectocuneiform facet and a more medially tilted facet for the entocuneiform; from C. kitcheneri in being larger and taller; from O. rufus in being less deep relative to height, with a less deeply concave talar head facet, separate dorsal and plantar sections of the ectocuneiform facet, more dorsally situated facet for the entocuneiform relative to the plantar margin of the ectocuneiform facet, and in lacking an eminence on the medial margin of the cranial surface between the dorsal ectocuneiform facet and the entocuneiform facet; from M. fuliginosus in being larger, and shallower relative to height, with separate dorsal and plantar sections of ectocuneiform facet, and in lacking an eminence on the medial margin of the cranial surface; and from W. bicolor in being much larger, with a taller plantar ectocuneiform facet and a slightly more plantarly situated entocuneiform facet.
Ectocuneiform (Fig. 55l–s): tall, transversely compressed, and tapering slightly dorsally in medial view, with a rounded dorsal margin (Fig. 55q). Facet for the navicular oval, gently concave and slightly laterally tilted, occupies the dorsal part of the caudal surface. Articular surface for the entocuneiform large and slightly concave, occupies the plantar part of the medial surface, with a small, irregular facet on the dorsal edge of the articular area. Facet for metatarsal III fairly narrow and concave, situated against the dorsal margin of the cranial surface; sits dorsal to a small, narrow, irregular eminence. Facet for the mesocuneiform small and rounded, immediately plantomedial to the metatarsal III facet. Plantar tubercle rounded in medial view, rugose and thickened at the plantar margin, with a slight medial deflection; lateral surface articulates with the medial plantar tubercle of the cuboid.
The ectocuneiform of P. mamkurra sp. nov. differs from that of P. viator sp. nov. in being slightly broader, with a broader, more oval and less plantarly extensive navicular facet and a shallower plantar tubercle that is more rounded in medial view; from P. otibandus in being larger and relatively slightly taller, with a gently rounded dorsal margin (rather than distinctly rounded-triangular); from C. kitcheneri in being larger, with a larger, less cranially deflected plantar tubercle and a broader, less plantarly extensive navicular facet; from O. rufus in being larger, with a more oval navicular facet, smaller cranial eminence, narrower, deeper, less plantarly projected and less cranially deflected plantar tubercle, and a relatively larger metatarsal III facet; from M. fuliginosus in being larger and broader, with a more oval navicular facet, smaller cranial eminence, and a deeper, less cranially deflected plantar tubercle; and from W. bicolor in being much larger, with a more oval navicular facet, smaller cranial eminence, and a larger, more rounded plantar tubercle.
Metatarsal IV (Fig. 56a–f): large and robust, shaft robustness index ~5.3–6. Dorsal cuboid facet has the medial part flat to gently concave and the lateral part flat to gently convex, such that the dorsal margin is slightly S-shaped in dorsal view; lateral component is laterally projected with its plantar margin tapering dorsally to a rounded point in proximal view;continuous plantomedially with the plantar cuboid facet. Proximal fossa shallow, abuts the proximal margin of the metatarsal V facet and the lateral margin of plantar cuboid facet. Plantar cuboid facet round to oval, slightly convex to concave, tilted slightly to sharply dorsomedially; situated opposite the proximal plantar sesamoid facet on the proximal surface of a thick, plantarly projected plantar tubercle. Facet for articulation with the plantolateral component of the ectocuneiform small, rounded, and medially tilted, situated on the proximal surface of the plantar tubercle, medial to and occasionally semicontinuous with the plantar cuboid facet.Proximal plantar sesamoid facet round to oval, flat to gently concave, facing plantolaterally to cranioplantarly. Articular surface for metatarsal III indistinct; situated in an elongate, rugose shallow fossa on the medial surface of the proximal end, bordered dorsally by a thin ridge extending distoplantarly from the dorsomedial corner of the dorsal cuboid facet. Dorsal facet for the ectocuneiform very small, on the medial surface of the proximal end, abuts the medial margin of the dorsal component of the dorsal cuboid facet. Facet for metatarsal V tall, proximodistally short; shape variable but generally oblong with rounded dorsal and plantar components; extending plantarly onto the lateral surface of the plantar tubercle.
Plantar ridge broad, rugose, extends distally from the base of the plantar tubercle with a very slight lateral deflection, gently merges into the plantar surface of the shaft around the midpoint. Shaft minimum width situated at around one-third of length from the proximal end, then expands gently, particularly on the lateral margin, to the broad distal end; shaft quite low in lateral view, becomes lower distally; dorsal surface of the shaft flat proximally, becoming gently rounded distally. Distal end broad; fossae for collateral ligaments circular and quite deep; keel slightly subequally to slightly more projected than lateral and medial ridges.
The metatarsal IV of P. mamkurra sp. nov. differs from that of P. anak in being slightly longer; from P. viator sp. nov. in being longer, with a larger plantar cuboid facet; from P. tumbuna in being larger; from P. dawsonae sp. nov. in having a larger plantar cuboid facet; from P. otibandus in being larger and more gracile, with dorsal and plantar cuboid facets continuous, and the plantar ridge more raised; from P. snewini in being larger and longer, with the dorsal and plantar cuboid facets continuous, the proximal cuboid fossa more plantolaterally situated, and a relatively longer plantar ridge; from C. kitcheneri in being larger, broader and more robust, with a larger, more plantarly projected proximal plantar tubercle and a more raised plantar ridge; from O. rufus and M. fuliginosus in being much shorter, less arched in lateral view and much more robust, with a larger facet for metatarsal V, less plantarly projected proximoplantar ridge and a broader, more planar proximal dorsal surface; and from W. bicolor in being much larger and more robust, with a relatively slightly larger proximal plantar tubercle.
Metatarsal V(Fig. 56g –k): broad and very robust, with length to distal facet width index ~4.1–4.8. Proximolateral process quite large, blunt, rugose, transversely compressed and slightly laterally deflected, contributing to the curved shape of the element in dorsal view. Facet for the cuboid broad and concave, covers most of the medial surface of the proximolateral process and continues plantomedially onto the proximal surface of the medial plantar tubercle (Fig. 56k). Facet for metatarsal IV oval to semicircular in dorsomedial view, extends over the dorsal part of the proximomedial surface; articular surface semicontinuous with the facet for the cuboid. Lateral plantar tuberosity broad, moderately elongate and rugose, for the partial insertion of the m. opponens digiti minimi; bounded on the medial margin by a narrow, shallow, curved plantar groove. Medial plantar tubercle small, rounded and plantomedially projected. Shaft broad; slightly arched in lateral view; cross-section oval and slightly compressed in an oblique plantolateral–dorsomedial plane; narrows toward the midpoint then broadens and increases slightly in height towards the distal end. Distal end very broad, with articular facets similar to those of P. anak.
The metatarsal V of P. mamkurra sp. nov. differs from that of P. anak in being generally slightly larger, and broader, with a thinner proximolateral process, cuboid facet less medially tilted in proximal view, broader, smaller and less proximally projected medial plantar tubercle, and a shallower, more curved plantar groove; from P. viator sp. nov. in being slightly longer, broader, and lower, particularly proximally, with a more dorsally situated and less plantomedially extensive facet for the cuboid; from P. tumbuna in being longer, more gracile and more obliquely compressed across shaft, with a more dorsally situated metatarsal IV facet, more elongate lateral plantar tuberosity, and a narrower distal end; from P. dawsonae in having a less distally extensive lateral plantar tuberosity; from P. otibandus in being larger and broader, with a thinner proximolateral process, larger, broader cuboid facet, and shallower plantar groove; from C. kitcheneri in being larger, broader and more robust, lacking the slight kink of the arch of the shaft immediately proximal to the midpoint in lateral view, with a larger lateral plantar tuberosity, larger medial plantar tubercle, and a larger, more caudally extensive facet for the cuboid; from O. rufus and M. fuliginosus in being relatively much broader and much more robust, with a longer, more laterally projected proximolateral process, broader, more plantomedially projected and more concave cuboid facet, and a broader distal end; and from W. bicolor in being much larger, relatively broader and more robust, with a larger proximolateral process.
Pedal phalanges (Figs 57 & 58): proximal phalanx IV: short, broad and dorsoplantarly compressed; proximal articular surface broad and domed, slightly flared laterally. Proximal plantar tubercles low and rugose, separated by a shallow groove. Shaft narrows slightly to a waist, then broadens to a broad distal end; trochlea broad and shallow; fossae for the collateral ligaments fairly shallow and semicircular. Middle phalanx IV: fairly short, broad and dorsoplantarly compressed. Proximal articular surface moderately concave, angled moderately dorsally; dorsal margin convex in dorsal view. Proximal plantar tubercles low and broad. Shaft fairly short with slight waist, broadens gently to distal end;trochlea broad and shallow;fossae for the collateral ligaments fairly shallow and semicircular. Distal phalanx IV: short and robust. Proximal end quite broad, with articular surface concave, and roughly pentagonal in proximal view; transverse margins with V-shaped indentation at midpoints (Fig. 57l). Plantar tubercle large and subrectangular. Shaft arches upward slightly before smoothly curving plantarly (Fig. 57k), with the dorsal peak rounded to very gently rounded-triangular; in dorsal view the medial and lateral margins are very slightly convex and taper slightly beyond the midpoint; tip rounded.
Proximal phalanx V: robust, with the proximal end slightly broader than tall, and large, rounded and rugose plantar tubercles. Proximal articular surface round, concave and medially displaced in proximal view. Shaft with a very slight waist; distal end with the collateral fossae very shallow and large. Middle phalanx V: very short, broad, dorsoplantarly compressed, and decreases in height distally; distinctly asymmetrical, with the proximal and distal surfaces medially and laterally tilted, respectively. Plantar tubercles low and rounded. Proximal articular surface gently concave, domed, tilted dorsally and slightly medially. Shaft extremely short and typically with no waist. Distal end with the fossae for the collateral ligaments tall, shallow and dorsally displaced; trochlea gently concave and the articular surface dorsoplantarly quite short. Distal phalanx V: short, broad and robust, bilaterally asymmetrical, with the dorsal peak medially displaced and the lateral part substantially broadened; proximal end roughly pentagonal in proximal view, medial and lateral margins with slight concavities at midpoints in proximal view; articular surface concave with a very slight medial ridge; plantar tubercle small and rounded in plantar view. Shaft arches upward gently before smoothly curving plantarly, with a slight, rounded dorsal peak; medial and lateral margins very gently convex in dorsal view.
The pedal phalanges of P. mamkurra sp. nov. differ from those of all compared taxa in their distal phalanges IV and V having a V-shaped divot in the medial and lateral margins of proximal end, and in the having the shafts of distal phalanges IV and V gently arched. They further differ from P. anak in being more elongate, with proximal phalanx IV having a more distinct waist that is situated more distally, middle phalanx IV with a relatively far narrower proximal end and a less proximoplantarly extensive distal articular surface; from P. viator sp. nov. in being generally slightly longer, with deeper collateral fossae on the proximal and middle phalanges, proximal phalanx IV with a broader waist, more elongate middle phalanx IV with relatively smaller, less distally extensive plantar tubercles, distal phalanx IV with a more rounded dorsal peak, and distal phalanx V less asymmetrical; from P. dawsonae sp. nov. in having proximal phalanx IV with a slightly broader distal end and a slightly narrower waist; from P. otibandus in being larger and more elongate, with proximal phalanx IV having a broader distal end and middle phalanx IV having a broader trochlea; from P. snewini in being larger, having more elongate middle phalanx IV with a broader distal articular surface and smaller fossae for the collateral ligaments, and a broader distal phalanx IV with a more rounded dorsal peak; from C. kitcheneri in being larger, broader and more dorsoplantarly compressed, with broader, shallower trochleae, middle phalanx IV with more a dorsally tilted proximal surface and less caudoplantarly extensive distal articular surface, and distal phalanges with a rounded, almost peak-less dorsal surface; from O. rufus and M. fuliginosus in being relatively shorter, broader, more dorsoplantarly compressed and much more robust, with distal phalanx IV having a more rounded, less pointed dorsal peak; and from W. bicolor in being larger and more robust, with middle phalanx IV having a more dorsally tilted proximal surface.
Remarks:
For a discussion of the taxa P. roechus Owen, 1874 and P. brehus (Owen, 1874) and their relationship to P. mamkurra sp. nov. and P. viator sp. nov., see the segment at the end of the ‘Systematic palaeontology’ section titled, ‘Status of other species previously referred to Protemnodon ’.
description: Published as part of Kerr, Isaac A. R., Camens, Aaron B., Van Zoelen, Jacob D., Worthy, Trevor H. & Prideaux, Gavin J., 2024, Systematics and palaeobiology of kangaroos of the late Cenozoic genus Protemnodon (Marsupialia, Macropodidae), pp. 1-261 in Megataxa 11 (1) on pages 59-100, DOI: 10.11646/megataxa.11.1.1, http://zenodo.org/record/10993768