Late Miocene hipparionine fossils from the Dhok Pathan Formation of Pakistan

Here, we have provided a detailed taxonomic description of equid fossils first time from Markhal, Chakwal District and Sulaiman Range, Sakhi Sarwar, Dera Ghazi Khan District in Punjab, Pakistan. The dental remains of hipparionins have been recovered from six which are Dhok Pathan Type Locality, Ochri, Gujjar Mehra, Molair Patti, Markhal, and Gharbin. These localities are dated to the Late Miocene to Early Pliocene period (10.2–3.4 Ma). The specimens described here contain both upper and lower dentitions belonging to two genera, Cormohipparion and Sivalhippus. During the Late Miocene, the palaeoenvironment of the Siwaliks is currently hypothesised to have had open habitats with a warm, arid environment. However, the presence of three-toed hipparionin equids suggests a wide range of complex paleoenvironmental conditions varying from grasslands to forest habitats. Furthermore, our study reveals complex dental structures in the extinct hipparionin species from the Siwaliks, indicating a dietary transition from C3 to C4 diet from browsing to grazing during the Late Miocene epoch.

Keywords: Equids; Siwaliks, Sulaiman Range, Late Miocene, Early Pliocene