Enhydriodon cf. falconeri Pilgrim, 1931

Enhydriodon cf. falconeri Pilgrim, 1931

(Fig. 2A1-A4)

HOLOTYPE. — BMNH/NHM 4847 , an isolated left P4 figured by Matthew (1929: 472, text-fig. 11) and by Pilgrim (1931: pl. 2, figs 3, 3a).

TYPE LOCALITY. — Indeterminate/unknown locality in the Siwaliks Hills ( Falconer 1868; Pilgrim 1931).

DIAGNOSIS. — Small species of Enhydriodon intermediate in dimensions between Sivaonyx bathygnathus and Enhydriodon sivalensis , with voluminous conical hypocone in P4 lacking ridge directed into central valley; two post-protocone cusps oriented linguodistally, the most lingual one not blocking the lingual outlet of the central valley. Parastyle large but low. “Lutrine crest” well developed and swollen, but not forming a separate cusp. Lingual opening of m1 trigonid narrow U-shaped ( Pickford 2007).

STRATIGRAPHIC RANGE. — Unknown, probably Tatrot to Pinjor formations ( Matthew 1929; Pilgrim 1932; Pickford 2007); Pinjor Formation (in this study).

REFERRED MATERIAL. — PUPC 83/01, right mandibular fragment with m1 and root of m2.

DESCRIPTION

The corpus is robust but not fully preserved (Fig. 2A1-A4). A deep mylohyoid line is present which subsequently joins the partially preserved pterygoid shelf at the lingual side while the preserved buccal side is bulged. Its preserved length is 40.1 mm. It bears an m1 and root of m2. The metaconid is partially broken in m1, rest of the tooth is well-preserved, and it is moderately worn. In m1, the paraconid is thick and eye-shaped as a result of moderate wear. It connects with the protoconid through a crest and forms a pronounced carnassial notch. The trigonid basin is small and lingually blocked by a portion of a long and strong mesial cingulid which covers the base of the tooth completely. The protoconid is thick and has the postprotocristid equipped with a well-developed cuspid. A large gap separates this cuspid from the buccal cusp of the talonid, i.e., the hypoconid and the closely attached hypoconulid. The entoconid is also well-developed. It connects with the meta- and hypoconulid through its crests and completely closes the distal and lingual side of the talonid basin. The talonid basin is much larger than the trigonid basin and partially open at its buccal side. There is a small diastema between m1 and m2. Only the alveolus with root of m2 is preserved. It was single-rooted and situated much higher than m1.

REMARKS

The wide paraconid and postprotocristid equipped with a well-developed cuspid, large talonid basin, more or less equally developed para-, proto-, and metaconid, and a large cingulid (Fig. 2A1-A4) associate the specimen with the genus Enhydriodon . There are two species of Enhydriodon known from the Siwaliks, E. falconeri and E. sivalensis ( Pilgrim 1932; Verma & Gupta 1992; Willemsen 1992, 1999; Pickford 2007). Enhydriodon falconeri is known from the latest Pliocene Tatrot Formation, while E. sivalensis has been recorded from the Middle to Upper Pleistocene Pinjor Formation ( Pickford 2007). The present specimen has been collected from Pleistocene outcrops of Bhimber, Azad Jammu Kashmir (AJK), that are equivalent to the Pinjor Formation. This further justifies its association with the genus Enhydriodon rather than Sivaonyx . However, the studied specimen is smaller than the known specimens of E. sivalensis , and morphologically PUPC 83/01 is extremely similar to GSI-D 161, described and figured by Pilgrim (1932) as E. cf. falconeri (see Fig. 2A4, A5) which is why we also attribute it to E. cf. falconeri . Nevertheless, it has been previously noted by Pilgrim (1932: 87) that “in respect of the structure of its ml, Enhydriodon falconeri closely resembles Sivaonyx . In fact, except by its larger size and the relatively slightly broader talonid it does not seem that the genera can be separated on the characters of m1 alone”.