North America is the true birthplace of the modern horse, and an extinct Chinese lineage known as the Dalian horse served as the genetic bridge that carried American horse ancestry into Europe, according to a new fossil DNA study published in Proceedings of the Royal Society B: Biological Sciences. The findings overturn the long-held assumption that horses were a European import to the Americas when Spanish conquistadors arrived.

The Dalian horse: from local oddity to evolutionary pivot

The Dalian horse, an extinct lineage once considered a regional curiosity from northeastern China, has been repositioned as a critical node in the story of equine evolution. Researchers say the animal carried a distinctly North American genetic signature and transmitted it to ancient horse populations in Siberia, ultimately seeding the bloodlines that gave rise to modern European horses.

Fossil specimens linked to this lineage were recovered from Gulongshan Cave in Heilongjiang province. The genetic data places the Dalian horse squarely within the late Pleistocene epoch, a period of dramatic faunal exchange across the Bering Land Bridge connecting North America and Northeast Asia.

Trans-Beringian gene flow: what the data shows

The study's authors concluded that “Dalian horses likely served as one route through which North American-related genetic ancestry entered Northeast Eurasian horse populations.” The research further notes that the findings “position the Dalian horse as a key lineage for elucidating late Pleistocene equid evolution in Northeast Asia and the dynamics of trans-Beringian genetic exchange.”

The mechanism, researchers say, was the Bering Land Bridge — a now-submerged land corridor between present-day Alaska and Siberia that periodically emerged during ice ages, allowing fauna to migrate between continents. Horses belonging to the genus Equus are believed to have crossed westward from North America into Asia, with the Dalian lineage acting as an intermediary population in northeastern China before that ancestry propagated further into Eurasia.

Why it matters

The conventional narrative — immortalised in accounts of Spanish conquistadors introducing horses to the New World — has always acknowledged that horses went extinct in the Americas roughly 10,000 years ago. What this study adds is the precise genetic pathway by which American horse DNA survived and eventually circulated back into European lineages, via Harbin-region fossils in Heilongjiang and populations in Yakutia.

The research rewrites the directionality of equine heritage: rather than Europe gifting horses to the world, North America appears to have been the foundational source, with China acting as an unlikely but pivotal relay point.

What’s next

Researchers are expected to expand ancient DNA sampling across additional cave sites in Northeast Asia and Siberia to map the full scope of trans-Beringian equid migration. As ancient genomics techniques improve, the evolutionary tree of Equus is likely to be refined further, potentially revealing additional intermediate lineages that shaped the horses humanity came to domesticate.