Old world hipparion evolution, biogeography, climatology and ecology

The Old World hipparionin review places first dispersal at 11.4–11.0 Ma and the latest regional records around or below 1 Ma; those dates are distinct from the broader North American tribe-level history.

Hipparionini is treated as a tribe of Equinae; Old World diversity is resolved into multiple genus-rank clades rather than a single broad genus Hipparion.

Hipparionini remained tridactyl and many lineages were hypsodont, while body size and foot proportions varied substantially across the radiation.

Old World hipparionins ranged from browse-dominated and mixed feeders to grazers, with ecology varying by lineage, body size, region and time.

The represented history distinguishes a North American tribe-level radiation from an Old World dispersal at 11.4–11.0 Ma and later regional Eurasian and African records.

Hipparionini retains four distinct displays: a heterogeneous 17–0.6 Ma navigation composite, a 17–2 Ma North American review envelope, an 11.4–11 Ma Old World dispersal window, and a 1–0.6 Ma selected terminal regional window.