New fossil mandible as well as isolated upper and lower dentitions of the late Miocene Hipparionine species, have been discovered from a locality of Chakwal, Punjab, Pakistan. By using morphometric and morphologic analysis, we have deduced that these specimens belong to Sivalhippus theobaldi. The body size of this species was intermediate between Sivalhippus perimensis and Hipparion antilopinum while its hypsodonty indicates that this species was a grazer to a larger extent which existed in mosaic of woodland and grassland in the Latest Miocene. However, the comparison with the recent horse (Equus caballus) mandible indicates some differences in dental and jaw lengths. The recent horse tends to have bigger and longer molars (higher hypsodonty indices) which may be attributed to a response towards changing vegetation, started at the end of the Miocene (ca. 6-7 Ma) strengthening the hypothesis that adaptive physiologies are a response towards a changing climate.

Article History

Received: Sep 12, 2022; Accepted: Mar 20, 2023; Published: Dec 27, 2023

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