Hoplitomeryx magnus Mazza & Rustioni 2011, SP. NOV.
Creators: name: Mazza, Paul P. A.
name: Rustioni, Marco
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Artiodactyla
Hoplitomerycidae
Hoplitomeryx
Hoplitomeryx magnus

description: HOPLITOMERYX MAGNUS SP. NOV.  (TABLE 1; FIGS 4, 5)   Holotype: Left hemimandible SCT 20.   
 Paratypes: Maxillaries SCT 18, SCT 86, RGM 260.951; mandibles RGM 260.951, RGM 261.135, RGM 261.144.   
 Type locality and horizon: Holotype and paratypes tagged SCT from the Tortonian Scontrone Member of the Lithothamnium Limestone (Patacca et al., 2008; 41°45′15.54″N, 14°2′13.14″E), outskirts of Scontrone, southern border of the National Park of Abruzzi, L’Aquila, central Italy. Paratypes RGM 260.951 come from the Messinian karstic fissure filling called S. Giovannino in a homonymous limestone quarry; RGM 261.135 comes from the Messinian karstic fissure filling called Nazario 4 in the limestone quarry Nazario; RGM 261.144 comes from the Messinian karstic fissure filling called Chiro 27 in the limestone quarry Chiro. The three quarries are located between Apricena and Poggio Imperiale, Foggia, Gargano promontory, south-eastern Italy (41°48′12″N, 15°23′04″E).   
 Preservation and deposition of type specimens: Scontrone specimens: Soprintendenza Archeologica dell’Abruzzo (Chieti, central Italy); Gargano specimens: Museum Naturalis, Leiden (the Netherlands).   
 Etymology: Refers to the particularly large dimensions of the individuals of the species.   
 Diagnosis: Apomorphies of species: mesodont cheek teeth (HI = 0.83); presence of upper canines; M1 with very reduced entostyle; paracone supported by robust and prominent median rib; external rib of metacone absent; well-developed and lingually protruding parastyle and mesostyle; metastyle very weak; cementum absent and overall smooth enamel in upper cheek teeth. Mandible with horizontal ramus massive lateromedially, ventral profile moderately convex under cheek teeth corpus; lower cheek dental formula: unknown at the moment in the Scontrone representatives, 2–3 in Gargano specimens; in p3 and p4 paraconid barely developed or totally absent and protoconid and metaconid of same height; lower molars with widely spaced, triangular, backwardverging labial cuspids and with flattened mesial enamel walls; protoconid and hypoconid isolated in unworn molars; in worn molars protoconid connected mesially with metaconid and distally with entoconid, and hypoconid connected with postprotocristid and postentocristid; lower molars with lingual cuspids relatively less worn than labial cuspids; metastylid and postentocristid prominent, but blunt; ectostylids blunt and robust; third lower molars with tear-shaped hypoconulid and entoconulid not fused distally; labial enamel wall corrugated, lingual wall smooth in lower cheek teeth; protoconids with faint traces of cingulum at their base. Premolar to molar ratio in the lower cheek toothrows: not assessable in the available specimens.   
 Differential diagnosis: See Table 1.   
 Description of holotype: Jawbone with pachyostotic horizontal ramus. m1–m2. Lingual conids higher than labial conids. Mesial enamel walls flattened. Premetacristid straight and weak. Metastylid and postentocristid prominent lingually, but blunt. Postprotocristid fused to pre-entocristid. Hypoconid isolated. Labial conids fairly spaced, with blunt, robust ectostylid in between growing progressively smaller from m1 to m3. Labial enamel wall moderately corrugated, lingual wall smooth. Faint traces of cingulum at the base of protoconid. Occlusal surfaces somewhat inclined outwards; inner cuspids fairly sharp and pointed, outer cuspids affected by relatively higher degrees of wear. m3 practically a slightly enlarged replica of m2. Hypoconulid and entoconulid maintain separated from one another.   
 Additional characters shown by paratypes: This, at the moment, is the largest of the species represented in the sample of cranial remains and mandibles from both Scontrone and Gargano. The root of a right upper canine is still preserved on the Gargano skull fragment RGM 260.951. The Scontrone representatives include a very fragmental maxillary of a young specimen, SCT 18, with P3 and P4 (both erupting), DP 4 in substitution, M1 and M2.   
DP4. Molariform, with very robust paracone labial rib; no metacone rib; well-developed parastyle and metastyle; very strong mesostyle. Protocone larger than metacone. Postprotocrista bent forward. As wear progresses, postparacrista and postprotocrista fuse to premetaconule crista. Small entostyle.  
P3. Strong styles and external rib of paracone. Protocone fairly small, centrally situated, lingually directed and fused to robust metaconule. Metacone relatively small. Two strong spurs issue from lateral enamel walls of lingual cusp, one from preprotocrista, the other from postmetaconule crista. Lingual enamel wall rougher than labial one. No entostyles.  
P4. Tooth preserved only on SCT 18, but still erupting.  
M1–M2. Robust parastyle and even stronger mesostyle. Strong external rib of paracone, metacone with no labial rib. Postprotocrista and postmetaconule crista fairly robust, and lingual crescents closely spaced. Lingual enamel wall more corrugated than labial one. No entostyle.  
p3. Tooth elongated mesiodistally, triangular in occlusal view. Parastylid robust, paraconid rudimentary and present only in unworn teeth. Protoconid and metaconid of same height, the latter markedly inclined backwards. Entoconid well developed and inclined like metaconid. Entostylid very weak. Hypoconid prominent labially but lower than entoconid. Labial enamel wall corrugated, lingual wall smooth. p4. Very similar to p3, but much larger and expanded labiolingually. Wear tends to concentrate particularly on talonid of tooth.  
m1–m2. Lingual conids tendantially higher than labial ones, also in worn teeth. Premetacristid tendentially straight and weak, fused, in worn teeth, to lingually bent preprotocristid. In unworn or slightly worn first lower molars preprotocristid in touch with metaconid, and postprotocristid with pre-entocristid. As wear progresses these structures normally fuse, protoconid mesially to metaconid and distally to entoconid. Hypoconid isolated at low levels of wear; as wear increases hypoconid fused to postprotocristid and then to postentocristid.  
 Measurements: See Table 2.   
Specimen incertae sedis RGM 261.138: a left maxillary fragment of a very small-sized ruminant from Gargano, RGM 261.138, still preserves P3 and P4. The dental characteristics of this remain differ from those of any other specimen from both Gargano and Scontrone.  
The most particular feature is the presence of three lingual cusps, aligned mesiodistally but well distinguishable from one another although fused together in a sort of crest-like structure. Moving distalwards, the single cusps can be distinguished by undulations in the enamel wall. Two of the cusps must be the protocone and metaconule. We excluded that the third could be interpreted as a paraconule because this is a primitive cuspule characteristic of very archaic artiodactyls. Therefore, the third cusp has been considered a residual metaconule.  
P3. Mesodont tooth. Three robust lingual cusps, aligned mesiodistally, are interpreted, moving distalwards, as the protocone and a double metaconule, fused together in a continuous crest-like structure. The protocone and parastyle are fused together mesially, as opposed to the distal metaconule, which is separated distally from the metastyle by a narrow fissure. The external rib of the paracone is strong, the styles, in contrast, are weak. The lingual and labial enamel walls are both smooth. Traces of cementum are present on the labial wall of the tooth. There is no entostyle.  
P4. Mesodont tooth. As in P3, three robust lingual cusps are aligned mesiodistally and fused together in a continuous crest, but in this case the protocone is weaker than the metaconule. The protocone and parastyle are fused together mesially, whereas the metaconule is separated from the metastyle by a narrow fissure distally. The external rib of the paracone and the styles are strong. The lingual and labial enamel walls are both smooth. Traces of cementum are present on the labial wall of the tooth. There is no cingulum or entostyle.
description: Published as part of Mazza, Paul P. A. & Rustioni, Marco, 2011, Five new species of Hoplitomeryx from the Neogene of Abruzzo and Apulia (central and southern Italy) with revision of the genus and of Hoplitomeryx matthei Leinders, 1983, pp. 1304-1333 in Zoological Journal of the Linnean Society 163 (4) on pages 1324-1326, DOI: 10.1111/j.1096-3642.2011.00737.x, http://zenodo.org/record/5442183