Order ARTIODACTYLA Owen, 1848
Suborder RUMINANTIA
Scopoli, 1777
Superfamily
Bovoidea Gray, 1821
Family Bovidae
Gray, 1821
Subfamily
Caprinae Gray, 1821
Tribe Caprini
Gray, 1821
Genus
Sinocapra Chen, 1991
Sinocapra willdownsi
sp. nov.
Holotype: AMNH 52139: left horn core and portion of orbit (52139A), fragmentary right horn core and corresponding frontal (52139A), fragmentary occipital region of skull (52139C, D), fragmentary right maxillary tooth row with P3-4, M1-2, isolated P2, and isolated left M1 (52139B), distal fragments left and right humerus (52139E), proximal fragment left ulna (52139E), distal fragment right metacarpal (52139E), first phalanx manus (52139E), first phalanx unknown position (52139E), second phalanx manus (52139E), fragmentary third phalanx manus (52139E), proximal fragment left and right femur (52139E), right metatarsal (52139E), right navicular-cuboid (52139E), right lunar (52139E).
Type Locality and Age: AMNH Limestone Corner locality (equivalent to UALP 8197 locality). Magnetozone C of chron C3n.3r GPTS. Approximately 4.95 to 4.50 Ma, immediately above the Hemphillian/Blancan boundary (as described in Lindsay et al. 2002).
Etymology: Named in honor of our late colleague and friend Will Downs, who worked extensively at the type locality of Panaca, Nevada (USA).
Diagnosis: An extinct Caprini of moderate size, but smaller than typical living members of the tribe, including Sinocapra minor. Horn core is short, nearly straight (no divergence), with a slight posterior curvature, moderately medio-laterally compressed, without transverse ridges, longitudinal grooves, or torsion, and hollow at base. Differs from S. minor in lacking a postcornual fossa. Specimen appears to represent adult female individual. P3-M2 are mesodont. Strong labial ribs occur between the parastyle, mesostyle, and metastyle. Distinct internal cavities occur between the protocone and metaconule on the M1-2. The metacarpal has a distinctive sulcus with slight crests (not sharp) parallel to the sulcus and is widely open (sagittal groove) at the distal epiphysis. The metatarsal has a sulcus on the dorsal surface, which extends from proximal to distal epiphyses, is apparent most of its length, and is prominent and open the distal third, with crests on both sides of the sulcus, and widely open (sagittal groove) at the distal epiphysis.