Palaeotragus Gaudry 1861
Creators: name: Laskos, Kostantis
name: Kostopoulos, Dimitris S.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Artiodactyla
Giraffidae
Palaeotragus

description: Genus Palaeotragus Gaudry, 1861
TYPE SPECIES. — Palaeotragus rouenii Gaudry, 1861 by original designation.
TYPE LOCALITY. — Pikermi, Greece.
AGE. — Late Miocene to Early Pleistocene.
GENERIC DIAGNOSIS (based on Geraads 1974; Churcher 1978). — Giraffids of small to medium size. Skull wide with long postorbital cranial part. Ossicones simple, straight to slightly curved with smooth surface, single paired, pointed, uprightly inserted on frontals in supraorbital position, widely spaced on the cranial roof, and subparallel to each other. Frontals concave between the ossicones. Diastema long; dentition brachydont, premolar section proportionally long. Metapodials elongate, slender with moderately to strongly deep central palmar/plantar through.
DESCRIPTION
Pentalophos sample (end MN9)
Studied material(LGPUT, Palaeotragus coelophrys). Right maxilla with P2-M3 (PNT-113); part of left maxilla with M2-M3 (PNT-165); upper right P2 (PNT-161); upper right P2-P3 (PNT-162); upper right P2-P3 (PNT-163); upper left P3 (PNT-164); part of right mandible with M 1 -M 3 (PNT-328F); part of right mandible with dP 2 -M 1 (PNT-121F); distal part of left humerus (PNT-166); proximal parts of a right and a left metatarsal (PNT-114F, PNT-119F). The taxon is represented by at least four adult and a juvenile individual. Measurements are provided in Appendix 2: Tables 1-4.
Upper dentition. All the labial ribs and styles of the premolars (parastyle, paracone, metastyle) are well developed (Fig. 2 A-C; Table 1). The hypocone is weak, but distinct. The enamel is finely rugose especially on the lingual side of the premolars. In some of the premolars there is a welldeveloped lingual cingulum (PNT-161, PNT-164; Fig. 2B, C). In the preserved P 2 and P 3 (Fig. 2 A-C) the parastyle and the paracone rib are close to each other and the enamel is folded in the area of the parastyle towards the paracone. Moreover, these teeth are inflated at the basis, lingually rounded and they delineate occlusally an almost half circle. The P2 of the PNT-113 toothrow (Fig. 2A) has a prominent disto-labial style that reaches almost 1/3 of the crown’s height. In the single available P4, the paracone is more centrally placed, still slightly folded towards the parastyle, and the tooth has a triangular occlusal shape. The fossettes of the P2 are distorted, but they look wide. The fossettes of the P3 and P4 are also wide and bear a hypoconal fold distally.
The upper molars are similar to those of other giraffids (Fig. 2A). The most prominent labial features are the parastyle, the paracone rib and the mesostyle. The metastyle is barely developed in the M1-M2, but similarly strong to the parastyle in the M3. Lingually, the protocone is more prominent than the hypocone, especially in the M3; hence the mesial lobe is wider and square shaped whereas the distal lobe is narrower and rounder. The fossettes converge towards the center of the tooth but they do not fuse. The hypocone flange reaches almost at the labial side of the molar, stopping just before the mesostyle mesially and the metastyle distally. The protocone flange almost reaches the parastyle mesially. Distally, it reaches almost at the center of the tooth. The enamel is finely rugose in all the molars, which also have a fine cement cover, mainly labially. Although in a less advanced wear stage, PNT-165 upper molars share the same basic morphological features with those of PNT-113. A lingual cingulum, occurs, especially on the mesial lobe.
Lower dentition. The right mandible PNT-328F preserves only the molars (Fig. 3A; Table 2). The mandibular height is 48.9 mm at the M 1 -M 2 level, and 53.6 mm below the distal lobe of M 3. All the lower molars preserve a fine cement cover. The most prominent lingual feature is the metastylid, and then the metaconid; the entoconid is traceable but less strong. In the disto-lingual side of the M 1 and M 2 the entoconulid is present but not prominent. The entoconulid of the M 2 is completely separated from the hypocone region in the upper part of the crown. The same applies probably for the entoconulid of M 1. The praentocristid penetrates in the mesial fossette, separating the labial and lingual side of the mesial lobe. The protoconid and the hypoconid are almost equally developed. An ectostylid is present on M 1, less developed on M 2, and absent on M 3. Finally, the hypoconulid is pointed labially and parallel to the protoconid and hypoconid. Lingually, the third lobe of the M 3 is separated from the second one by a shallow furrow. The cingulum appears strong on M 1, but weak on M 2 and absent on M 3.
Lower deciduous dentition. The right mandible PNT-121F (Fig. 3B; Table 3) consists of the series of the deciduous premolars and the M 1. The dP 2 has a primitive morphology. The paraconid and anteparaconid are barely distinguished from each other. The protoconid is placed medially and it is the more developed conid. Distally, the entoconid and the hypoconulid are distinguished in the upper part of the crown, whereas they fuse in the lower. The hypoconid is prominent, placed more labially.
On the dP 3 the paraconid and anteparaconid are pointed lingually and they are well-distinguished in the upper half of the crown, whereas they fuse each other towards the base. The metaconid and the protoconid are the most prominent features (especially the protoconid); they fuse distally and they are folded and oriented mesially. The mesosinusid is lingually open. The distal and mesial part of the dP 3 are clearly separated in the area of the metaconid and protoconid fusion. The hypoconulid is as developed as the protoconid. The hypoconulid and the entocristid are distinguished only in the upper part of the crown. The metasinusid is clear but weaker than the mesosinusid.
The dP 4 has two prominent ectostylids. The mesial lobe is distorted, although it seems that its ribs and stylids are weaker. In the two distal lobes the labial cones are equally developed. The lingual ribs and stylids are weaker too, as in the mesial lobe. The distal flange of the third labial cone reaches the lingual side of the tooth. The distal flange of the second labial cone is also well-developed and it is placed next to the metastylid; it is the feature that separates the second from the third lobe.
The M 1 morphology agrees with the morphology of the M 1 from the adult toothrow PNT-328F: the metaconid, metastylid, entoconid and entoconulid ribs are quite welldeveloped in the upper half of the crown.
Postcranials. The distal part of the left humerus PNT-166 is badly preserved prohibiting a detailed morphological description. The olecranon fossa is rather long, narrow, and deep. The lateral supracondyloid crest is well developed and raises quite high on the distal diaphysis. Both the radial and coronoid fossae are shallow and weakly separated by each other (but also probably due to the bad preservation). The distal trochlea is asymmetric and its keel wide and rather blunt. In lateral view, the lateral epicondyle slopes weakly downwards, whereas in medial view the medial epicondyle is perpendicular compared to the diaphysis longitudinal axis and not significantly protruding.
The preserved proximal parts of the metatarsals PNT-114F and PNT-119F (Fig. 4A, B; Table 4) indicate rather long but relatively robust metapodials. On the proximal articular surface, the plantal and dorsal heads of the medial epicondyle are separated by a bone protrusion, whereas a groove separates the two heads on the lateral side. The plantar head does not tilt medially or laterally. The lateral dorsal head is placed parallel to the proximal articular surface’s axis. The pygmaios is present but rather small and not prominent.
Ravin de la Pluie sample (MN10)
Studied material (LGPUT, Palaeotragus cf. coelophrys). A ‘hornless’ skull with a highly worn toothrow (RPl-91B); part of right mandible, with highly worn M 1 -M 3 (RPl-104F); isolated upper molar (M 1 or M 2) (RPl-315n). The taxon is represented by at least an adult and an old individual. Dental measurements are provided inAppendix 2: Table 5.
Cranium (RPl-91B). The skull is strongly deformed (Fig. 5), and hence a thorough description is prevented. Geraads (1978) provided the basic recognizable cranial and dental features; we repeat here the most important ones and add a few more. The cranium lacks ossicones, and has a flattened frontal region (Fig. 5B) suggesting a female individual. The parietal region is highly lateromedially compressed. The postorbital region is elongated. The mesial border of the orbit reaches almost at the level of the center of the M3 (Fig. 5A). The length from the mesial margin of the orbit to the mesial root of P2 is 153.8 mm. The height of the orbit is 58.9 mm, while its horizontal (caudo-rostral) diameter is 59.2 mm. The width of the region of the frontal bone behind the orbits is 95.4 mm.
Upper dentition. The toothrow of the cranium RPl-91B is strongly worn (Fig. 5C). The premolars’ width is similar to that of the molars, especially the width of the P4. The P2 and P3 are lingually rounded. Labially, the parastyle, paracone rib, and metastyle are all well-developed, with the paracone rib set mesially and close to the parastyle. The premolar fossettes demonstrate a slight hypoconal fold. P4 is labially more flattened and more pointed lingually than the P 2 and P3; a weak, shallow lingual furrow unequally divides the lingual cone. P4 also has a strong parastyle, paracone rib and metastyle. The upper molars have a thin cement cover labially. The protocone widens significantly at the basal part of the crown; it is slightly constricted lingually on M1 and M2, and more angular on M3. The labial ribs and styles are extremely worn but apart from the parastyle they do not seem well-developed.
Lower dentition. The mandible RPl-104F preserves only the molars (Fig. 6A; Table 6). The mandibular height is 48.9 mm at the level of M 1 -M 2 and 53.6 mm at level of the distal lobe of the M 3. The lingual ribs seem very weak though the dentition is in a very advanced wear stage. Labially, the lobes of the M 1, and but less those of M 2 are pointed and centrally oriented, while those of M 3 are directed more distally. The distal (3rd) lobe of M 3 is quite large and disto-labially oriented, separated lingually from the rest of the tooth by a slight groove. There is no evidence of cingulum or cement on the molars.
Xirochori sample (MN10)
Studied material (LGPUT, Palaeotragus sp.). Right mandible fragment with M 2 -M 3 (XIR-24). The taxon is represented by a single adult individual. Measurements are provided in Appendix 2: Table 7.
The lingual ribs and stylids are weak on the preserved M 2 and M 3 of XIR-24 (Fig. 6B)but the metaconid and the metastylid are quite prominent. The second and third lobes of the M 3 are separated by a very shallow groove. Labially, the protoconid and the hypoconid direct distally and they are both fairly more pointed in the M 2 than in the M 3. A weak entoconid is observed on the M 2. A strong ectoconid is observed between the first and the second lobe of M 3, while there is a weaker one between the second and the third lobe. Neither cingulum nor cement are observed.
Nikiti-1 sample (end MN10)
Studied material (LGPUT, Palaeotragus aff. berislavicus). A partial cranium preserving both toothrows and the very proximal part of the ossicones (NKT-172); a left humerus distal articulation (NKT-161); three left radii (NKT-156, NKT-159, NKT-169); a right radius (NKT-155); a proximal part of radius (NKT-167); two right metacarpals (NKT-137, NKT-141); a left metacarpal (NKT-131); two proximal parts of left metacarpals (NKT-26, NKT-67); a right tibia (NKT-271); two distal parts of tibia (NKT-150, NKT-154); two left astragali (NKT-163, NKT-266); a right astragalus (NKT-267); two right calcanei (NKT-153, NKT-268); four left metatarsals (NKT-133, NKT-136, NKT-139, NKT-160); two right metatarsals (NKT-138, NKT-144); a distal part of a right metatarsal (NKT-151); three proximal parts of right metatarsals (NKT-132, NKT-140, NKT-168). The taxon is represented by at least four adult and a possibly young individual. Measurements are provided in Appendix 2: Tables 8-14.
Cranium (NKT-172). The cranium is badly crashed, moderately deformed, and laterally compressed (Fig. 7). It preserves both toothrows but in the left one the molars are very badly preserved (Fig. 7C). The mesial margin of the orbit reaches the level of M3. The length from the mesial edge of the orbit to the mesial root of P2 is 154 mm. A pair of supraorbital ossicones is present, both broken near the base (Fig. 7A). It can be assumed that the ossicones are placed relatively medially compared to the dorso-lateral orbital margins, although the skull is very deformed. The basal anteroposterior diameter of the ossicones is 43.4 mm, while the transverse diameter is c. 32 mm. Their cross section is oval shaped with main axis trending anteroposteriorly.
Upper dentition. The labial side of the left molars of NKT-172 is damaged (Fig. 7C; Table 8). The toothrows are not very worn. The P2 and P3 have a circular occlusal outline. Labially, the parastyle and the paracone ribs are well-developed, whereas the metastyle is weak. The fossettes of the P2 and the P3 are wide and U-shaped. A hypoconal fold can be seen in the distal part of the P3’s fossette. Compared to the P 2 and P 3, the P 4 has a more pronounced metastyle, and a less convex lingual wall giving to it a more squared occlusal outline. The central fossette of the P4 is wide and simple. On the disto-lingual part of the P4 there is a style that reaches almost to the half of the crown height.
The basic morphology of the molars is similar to those of other giraffids (Fig. 7C). The M2 and M3 are slightly worn and have well-developed parastyle, paracone rib, mesostyle and metastyle. The labial rib of the metacone is almost flat. A weak labial cingulum is present on M 1 and M2. On the M3 a labial style is attached on the basis of the metacone. Lingually, the protocone and the hypocone are almost equally prominent and of similar shape on the M1 and M2. In the M3 the protocone protrudes lingually more than the hypocone. The distal protocone and mesial hypocone flanges converge in the middle of the tooth. The distal hypocone flange tends to connect with the metastyle; they are already connected in the less worn M3. The size of the mesial fossette is small. Mesially, the protocone flange is connected to the parastyle. Both fossettes are U-shaped. There is a very weak hypoconal fold in the M2.
Postcranials. The preserved distal humerus (NKT-161) is crashed and deformed preventing reliable morphological observations (breadth of distal epiphysis: 85.4 mm; width of distal epiphysis: 40.94 mm). Its size is intermediate between those of P. rouenii and P. coelophrys. It has the same width as a P. microdon specimen described by Bohlin (1926). On the NKT specimen, the olecranon fossa is deep, wide and U-shaped.
The radii are all elongated (Fig. 8A, B) and moderately slender. Two of the NKT radii are fairly curved (concave laterally; NKT-155, NKT-156; Fig. 8A, B; Table 9), while the rest three are straighter (NKT-159, NKT-167, NKT-169). The cross section is crescent-shaped in the proximal 4/5 of bone’s length, with rounded cranial and straight caudal faces; it is trapezoidal shaped in the distal most 1/5 of radius length. The two epiphyseal areas are both much wider than the shaft, and they both expand medially and laterally. In the specimen NKT-159 the olecranon is partly preserved. It seems to greatly tilt latero-distally. Proximally, the medial, rectangular/subrectangular shaped articular surface is much larger than the quadrangular lateral one, separated by each other by a wide, shallow furrow (Fig. 8A 1, B1). The medial tuberosity is not developed. A tilted narrow crest divides the distal articular surface into two equal subregions, representing the articular surfaces for the scaphoideum and semilunare, respectively.They are both round and slightly concave. The semilunare surface is interrupted by a convex protrusion distally. The groove for the extensor carpi radialis muscle at the cranial part of the distal epiphysis is wide, and very shallow to flattened, delimited by blunt ridges (Fig. 8A 2, B2).
The best preserved metacarpals (Fig. 8C, D) vary slightly in length (Table 10), having however similar robusticity indices (8.38-8.75%). The lateral and medial epicondyles are asymmetrical. The lateral epicondyle has half the size of the medial one, and it is of square or rectangular shape. The medial epicondyle is rounded dorsally and has an overall shape of a half to ¼ of a circle. The fossa in-between the two epicondyles continues in the medial epicondyle. The medial and lateral epicondyles continue to the medial and lateral ridges respectively, which are of similar width and morphology. They are both rounded near the proximal end and they become slenderer and sharper in the shaft area. The central trough is very deep near the proximal end of the bone but becomes shallower and flatter towards the distal end. The trough’s width is variable. However, it can be said that the longer the bone, the wider is the trough. The pyramidal rise is absent in most of the specimens apart of NKT- 137 in which a slight protrusion could be attributed to the pyramidal rise; however, it is not prominent at all. The keels of the distal epicondyles are more prominent palmary, and they also extend onto the distal end of the palmar side of the shaft.
Three tibia specimens are preserved (Table 11). Proximally, the angle of the sulcus mascularis is obtuse when compared to the bovid or cervid anatomy (Fig. 9A, B). The tuberosity is not well preserved but does not seem to be pronounced (Fig. 9). The lateral condyle is somewhat damaged laterally and cranially. In the better preserved distal tibial fragment NKT-154 the cross section of the distal shaft is sub-rectangular. The distal articular surface has a broad rectangular shape, and the articular surface for the medial malleolus is quite prominent (Fig. 9C). The cochlear crest, that separates the cochlear furrows, is moderately prominent forming a strong caudal and a weak cranial crest.
The size of the three preserved NKT astragali (Fig. 10; Table 12) is intermediate between the groups of small and large Palaeotragus. The NKT astragali are rectangular in shape, as the lateral and medial lengths are of almost equal size and not thickened medially. In dorsal view the lateral edge of the trochlea tilts slightly medially. The central fossa is large, deep and triangular. The medial groove is weak in NKT-266; it is damaged in the other two specimens. The lateral notch is faint in NKT-266, prominent in NKT 267 (Fig. 10A) and intermediate in NKT-163 (Fig. 10B). The median depression is wide and deep in NKT-163 and NKT-266 but shallower in NKT-267.Ventrally, the medial ridge tilts medially in the specimens NKT-266 and NKT-267 (Fig. 10A), while it is almost vertical in NKT-163 (Fig. 10B). The intertrochlear notch is deep and narrow in NKT-163, but it is wide and shallow in NKT-266 and NKT-267 (Fig. 10). The proximal triangular fossa is prominent and the interarticular groove absent in all the specimens.The medial scala is absent in NKT-267, weak in NKT-266 (Fig.10A) and slightly more prominent in NKT-163 (Fig. 10B). The distal intracephalic fossa is absent in NKT-266 and NKT-267; in NKT-163 it probably exists, although the preservation status of the specimen does not allow to be decisive (Fig. 10). The lateral and medial crests are equally thick, with the lateral pointing posteriorly, and the medial slightly tilting medially. The lateral side of the astragali is somewhat concave.
Two right calcanei were collected. The calcaneus NKT-153 (Fig. 11; Table 13) is larger, with a more robust corpus than NKT-268. However, the NKT-268 head seems to be stronger relatively to the corpus, than the NKT-153 one.Both the dorsal and plantar crests are parallel to the bone axis. The calcaneal tuberosity is prominent, though weathered in both specimens. In NKT-268 a medial crest separates the calcaneal tuberosity from the rest of the calcaneal corpus. The sustentaculum tali is somewhat damaged in NKT-153 (Fig. 10B, C), while it is robust in NKT-268. The proximal-plantar articular surface for the astragalus consists of two concave surfaces, with the plantar one being almost double in size than the dorsal surface. Medially, the articular surface for the astragalus is fairly deep and concave. The articular surface for the scaphocuboideum is located plantarly and is slightly damaged in both specimens. Dorsally, there is a well-developed, articular facet for the malleolus.
The metatarsals (Fig. 12; Table 14) demonstrate a variation in both the total length and the robusticity indices (7.3-12%), also partly due to postmortem deformation (e.g., NKT-133). The lateral epicondyle is smaller and subdivided in two regions, the dorsal and the plantar heads (Fig. 12A). In contrast, in the medial proximal epicondyle this separation is not evident. The medial epicondyle has a trapezoid shape (Fig. 12A). The lateral dorsal head is more circular. The shape of the lateral plantar head is intermediate in shape. The pygmaios is not preserved (Fig. 12A, B). The central trough varies in the studied specimens. However, it is significantly shallower and it disappears from the middle towards the distal end of the bone (Fig. 12B). The width of the trough also varies, and it seems to follow the total bone width. The proximo-plantar fossa is present, weak and communicates with the central trough in the specimen NKT-139 whereas the bad conservation status of the other specimens does not allow to identify it. In contrast to the metacarpals, a dorsal trough is evident; it is deeper at the proximal end of the bone, becomes shallower downwards and disappears at the distal end (Fig. 12D). The distal epiphysis of the metatarsals is similar to that of the metacarpals.
description: Published as part of Laskos, Kostantis & Kostopoulos, Dimitris S., 2022, The Vallesian large Palaeotragus Gaudry, 1861 (Mammalia: Giraffidae) from Northern Greece, pp. 437-470 in Geodiversitas 44 (15) on pages 439-447, DOI: 10.5252/geodiversitas2022v44a15, http://zenodo.org/record/6518430