Sivatherium giganteum Falconer and Cautley, 1836

Rios, M, Danowitz, M & Solounias, N, 2016, First comprehensive morphological analysis on the metapodials of Giraffidae, Palaeontologia Electronica 410 (10453), pp. 1-39 : 15

Sivatherium giganteum Falconer and Cautley, 1836

Specimens. NHM UK 39752, NHM UK 39753 Description. The proximal articular surface exhibits three distinct facets. The lateral facet for the os naviculocuboideum is kidney-shaped. The medial facet for the os cuneiforme intermediolaterale is half-moon shaped and contacts the os cuneiforme mediale facet in a small point. The lateral epicondyle is larger with a flatter surface. It is divided into a plantar and a dorsal head by a deep longitudinally oriented groove ( Figure 5.3 ). The plantar head is oriented longitudinally, and the dorsal head flares outward ( Figure 16 ). The medial epicondyle protrudes more due to a circular bony protrusion on the plantar surface ( Figure 17). It is split into a plantar and a dorsal head by a shallow, wide groove on the medial shaft. Both heads slightly flare outward ( Figure 9 ). The medial and lateral epicondyles are separated by a wide, flattened groove. There is no discernible pygmaios. The medial and lateral ridges are very rounded and small, creating a flattened central trough. The distal shaft flares outward, notably on the lateral edge. There is no visible pyramidal rise. The keels of the distal condyles slightly extend onto the plantar surface of the distal shaft.

Figures

FIGURE 5. Palmar views of the right metacarpals (left) and plantar views of metatarsals (right) of certain Giraffidae. 1, Helladotherium duvernoyi, late Miocene, Pikermi, NHM 11382 (metacarpal), MNHNP 1554 (metatarsal) (both reversed); 2, Bramatherium megacephalum, late Miocene-Pliocene, Siwaliks, AMNH 29820, (metacarpal), AMNH 19668 (metatarsal); 3, Sivatherium giganteum, Pleistocene, Siwaliks, NHM 39553 (metacarpal), NHM 39752 (metatarsal); 4, Decennatherium pachecoi, late Miocene, Los Valles de la Fuentidueña, MNCN 42769 (metacarpal), MNCN 42764 (metatarsal) (both reversed); 5, Birgerbohlinia schaubi, late Miocene, Piera, IPS 5060 (metacarpal), Crusafont, 1952, fig. 15-5 (metatarsal), (both reversed); 6, Okapia johnstoni, Zaire, AMNH 51196 (metacarpal), AMNH 51196 (metatarsal). Scale bar equals 200 mm.

FIGURE 9. Sivatherium giganteum from the Upper Siwaliks. 1, Right metacarpal NHM UK 39533; 2, Left metatarsal (reversed) NHM UK 39752.

FIGURE 16. Three selected metatarsal characteristics. This simplified table can be used to facilitate specimen identifications and differentiate between different giraffid taxa.