Taxonomic assessment of tragulids from the Chinji Formation (late Middle Miocene) outcrops of Chabbar Syedan, Punjab, Pakistan

The present study deals with the remains of family Tragulidae collected from the Chinji Formation (Lower Siwalik subgroup; late Middle Miocene) deposits of the Chabbar Syedan, Jhelum, Punjab, Pakistan, and their palaeodietary habits through mesowear analysis (Mesowear-II). The morphometric comparison revealed that these remains belong to four species of three genera: Siamotragulus cf. nagrii, Siamotragulus sp. ‘Dorcatherium’ cf. minus, and Dorcabune cf. nagrii. The specimens of S. cf. nagrii confirm its presence in the Chinji Formation, rather than only in the Dhok Pathan Formation, as recently suggested. Specimens of Siamotragulus sp. further hint at the presence of a larger species of the genus in the Siwaliks. The described specimen of Db. cf. nagrii not only confirms its presence in the Chinji Formation but also its rarity, as indicated by the only specimen in the entire collection. The mesowear analysis of these fossils suggests that the described species were browsers, and combined with previously reported crown height, microwear and isotopic data for the Siwalik tragulids, it is deduced that these taxa probably fed on fruits, leaves, and shoots while living in the vicinity of aquatic environments, either rivers or lakes. A detailed reassessment of the Siwalik tragulids is direly needed and suggested for future studies.