Sivaonyx bathygnathus ( Lydekker, 1884 )

Sivaonyx bathygnathus ( Lydekker, 1884)

HOLOTYPE. — GSI D 33 , left mandible with p4-m1 and alveoli of c1-p3 ( Lydekker 1884).

TYPE LOCALITY. — Hasnot, Punjab, Pakistan ( Lydekker 1884).

DIAGNOSIS. — Large species of the genus Sivaonyx with slightly sectorial aspect to P4 and m1, but showing a talonid basin broader than the trigonid ( Pickford 2007).

STRATIGRAPHIC RANGE AND GEOGRAPHIC DISTRIBUTION. — This species well-known from the Late Miocene, Dhok Pathan Formation of Siwaliks ( Pilgrim 1932; Pickford 2007) and Southern China ( Zong 1997; Qi et al. 2006).

REFERRED MATERIAL. — PUPC 16/29, lp4.

DESCRIPTION

PUPC 16/29 is a left p4. The base of tooth is partially broken postero-lingually. It is monocuspid, slightly worn and subtriangular in shape. It has a thick and strong cingulum at the base labio-lingually. The protoconid is large, pyramidal, slightly compressed buccally and highest. The distal cuspid is small, slightly buccally positioned, and separated from the protoconid by a small notch. A wide basal platform is present in the front of the distal cuspid lingually. It is double-rooted, and the distal root is more preserved (Fig. 2C1-C3).

COMPARISON

The described p4, PUPC 16/29, is broad distally, with a strong, and a broad cingulid, no mesial accessory cusp, outwardly situated distal cusp; and these are the characters of p4 given in the diagnosis of Sivaonyx bathygnathus given by Pilgrim (1932). Further, while describing p4 (GSI-D 244), Pilgrim (1932) writes: “distal accessory cusp is almost as strong and probably little inferior in height to the main cusp and it lies well on the outside of the median axis” and the same morphology is described by Pickford (2007), i.e., presence of a distal accessory cusp, a cingulid that covers the base of whole tooth, and a broadly expanded distal platform. In this regard, morphology and dimensions of the specimen (Fig. 2C1-C3; Table 2 View TABLE ) are close to S. bathygnathus , hence, we referred it to Sivaonyx bathygnathus .