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 : 5

Sivatherium giganteum Falconer and Cautley, 1836

Specimen. NHM UK 39533

Description. The medial and lateral epicondyles are asymmetrical in size and morphology ( Figure 9 ). The medial part is smaller, triangular, and exhibits several raised ridges on the surface. The lateral epicondyle is larger, square shaped, and possesses several sub facets ( Figure 7 ). There is a very faint, obliquely oriented groove on the lateral epicondyle ( Figure 5.3 ). The proximal articular surface extends slightly onto the palmar surface of the lateral epicondyle. There is a deep groove separating the medial and lateral epicondyles which strongly flare outward, and it continues onto the central trough. The medial ridge is rounded and extends from the distal aspect of the medial epicondyle. The ridge is thicker at the midshaft, is thin proximally and distally, and it ends abruptly towards the distal shaft. The lateral ridge is sharper and is continuous longitudinally on the shaft. There is an elongated oval fossa lateral to the lateral ridge, which extends from the lateral epicondyle to midshaft ( Figure 4 ). The central trough is intermediate in depth, and it flattens towards the distal shaft. The distal metacarpal is spatula shaped and flares outward. The lateral distal condyle extends further distally than the medial distal condyle (distance ~ 4 mm). The lateral aspect of the lateral distal condyle flares whereas the medial aspect of the medial distal condyle is more vertical. The keels of the distal condyles extend onto the palmar distal shaft.

Figures

FIGURE 4. Three selected metacarpal characteristics. This simplified table can be used to facilitate specimen identifications and differentiate between different giraffid taxa.

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 7. Three additional metacarpal characteristics. This simplified table can be used to facilitate specimen identifications and differentiate between different giraffid taxa.

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