Hoplitomeryx macpheei, Van Der Geer, 2014

Van Der Geer, Alexandra A. E., 2014, Systematic revision of the family Hoplitomerycidae Leinders, 1984 (Artiodactyla: Cervoidea), with the description of a new genus and four new species, Zootaxa 3847 (1), pp. 1-32 : 25-26

publication ID	https://doi.org/ 10.11646/zootaxa.3847.1.1
publication LSID	lsid:zoobank.org:pub:C7BDD136-2686-4049-B395-684797B26406
DOI	https://doi.org/10.5281/zenodo.5630052
persistent identifier	https://treatment.plazi.org/id/03D287A2-FD11-371D-FEF7-FD91FF66FDA5
treatment provided by	Plazi
scientific name	Hoplitomeryx macpheei
status	sp. nov.

Treatment

Hoplitomeryx macpheei sp. nov.

Fig. 7 View FIGURE 7 F–I

Hoplitomeryx Leinders, 1984 , horn core type II—Leinders 1984: p. 21, 22, pl. 5B [RGM 260.902].

Hoplitomeryx Leinders, 1984 , size 3— Van der Geer 2005 (partim): p. 331, 332; Van der Geer 2008: p. 153, 154, fig. 4, 6.

Hoplitomeryx matthei Leinders, 1984 — Mazza & Rustioni 2011 (partim): p. 1320, fig. 3, 6 [RGM 261.141].

Hoplitomeryx magnus Mazza et Rustioni, 2011 — Mazza & Rustioni 2011 (partim): p. 1324, 1325, fig. 4 [RGM 260.951, RGM 261.135].

Holotype. Left metacarpal RGM 260.918 .

Paratypes. Proximal humerus RGM 260.950, distal humerus RGM 425.278, radius-ulna RGM 425.282 ( Fig. 4 View FIGURE 4 E), radius RGM 260.866, unciform RGM 425.264, anterior first phalanx RGM 260.861, anterior second phalanges RGM 260.886 and RGM 261.143, femur RGM 425.245 ( Fig. 5 View FIGURE 5 M), patella RGM 425.246 ( Fig. 5 View FIGURE 5 N–P), tibia RGM 260.854, astragals RGM 260.863 ( Fig. 6 View FIGURE 6 D) and RGM 260.890, calcanei RGM 260.883 and RGM 425.313, first phalanges RGM 260.913 and RGM 260.909, seventh cervical vertebra RGM 425.307, nasal horn core RGM 260.902, associated left and right hemimandibles and maxilla RGM 260.951.

Referred specimens. See Appendix III, and Fig. 4 View FIGURE 4 A.

Diagnosis. A large-sized hoplitomerycid. Estimated body mass 78.0 kg. The fusion between radius and ulna is weak and the ulna leaves no trace on the radius. The shaft of the tibia is almost straight. The astragal is non-parallel sided.

Differential diagnosis. About twice the body size of H. matthei . The lateral horn core is compressed anteroposteriorly unlike the circular cross section seen in H. matthei (horn core type I).

Derivation of name. Named after Ross D.E. MacPhee, curator of mammals at the American Museum of Natural History in New York, in honour of his contributions to the knowledge of the evolution and extinction of insular mammals.

Preservation and deposition. Naturalis Biodiversity Center, Leiden, the Netherlands (formerly Rijksmuseum van Geologie en Mineralogie (RGM)).

Type locality and horizon. Late Miocene (Middle or Late Turolian, MN12-13) fissure filling with code San Giovannino in an abandoned limestone quarry near the farm of San Giovannino south of the provincial road between Poggio Imperiale and Apricena (Province of Foggia, Apulia, Italy).

Studied localities. Fissure fillings with codes Biancone 2, Chirò 2, 3, 5A, 13, 20A and E, 28 and D3, Fina H and N, Gervasio, Pizzicoli 1, 4 and 12, San Giovannino. All localities are located in the north-western portion of the Gargano Peninsula, Apulia, south-eastern Italy.

Description of holotype. RGM 260.918 is an almost complete metacarpal of which only the distal trochlea is missing distalward of the (fused) epiphyseal line. Its general morphology corresponds to that of Cervus but more slender. The crest that separates the medial and lateral articulation is broken but seems to have ended in the central fossa, making an angle of about twenty degrees with the parasagittal plane. The central fossa is large, situated more or less centrally and makes only minimal contact with the palmar surface. The attachment area for the carpal ligaments on the dorsal surface is weakly developed. The palmar groove for the M. interosseus palmaris is only proximally expressed. The scars for the lateral metacarpals are pronounced.

Measurements. Holotype: maximal length = 190 mm, proximal depth (DAPP) = 17.5 mm, proximal width (DTP) = 30.1 mm, distal depth (DAPD; estimated at epiphyseal line) = 13.1 mm, distal width (DTD; estimated at epiphyseal line) = 27 mm. The distal diameters are confirmed by referred distal metacarpal RGM 261.530: DAPD = 14.7 mm, DTD = 28.2 mm. For other measurements of referred specimens, see Appendix III (linear measurements) and Appendix I and II (body mass estimations).

Remarks. Skull fragment RGM 261.099 (horn core type IV in Leinders 1984; Pizzicoli 5) represents an animal larger than the type species ( H. matthei ) but seems not large enough for the largest size group and is here attributed to H. macpheei sp. n.. RGM 261.099 might further be an indication that the configuration and morphology of the horn cores may differ between the species in addition to between the sexes. The lack of associated posterior skull parts and / or maxillae with horn cores hampers a more precise diagnosis based on horn core types. The holotype is more slender than the referred proximal metacarpal RGM 425.322 from the same fissure filling. They likely represent a female and a male individual respectively. The morphology of the proximal articulation of both specimens was earlier described as morphotype 1 ( Van der Geer 2005), but RGM 425.322 has a more pronounced crest than the holotype. Patella RGM 425.246 fits perfectly well on the distal femur RGM 425.245.