Leporid

Evolution

The oldest known leporid species date from the late Eocene, by which time the family was already present in both North America and Asia. Over the course of their evolution, this group has become increasingly adapted to lives of fast running and leaping. For example, Palaeolagus, an extinct rabbit from the Oligocene of North America, had shorter hind legs than modern forms (indicating it ran rather than hopped) though it was in most other respects quite rabbit-like. The last common ancestor of the leporids likely had features not present in the last common ancestor of the lagomorphs, according to a 2022 study of the extant and extinct known lagomorphs—an intercranial joint and a facial tilt, specifically. Two as yet unnamed fossil finds—dated ~48 Ma (48 million yr) ago (from China) and ~53 Ma (53 million yr) ago (India)—while primitive, display the characteristic leporid ankle, thus pushing the divergence of Ochotonidae and Leporidae yet further into the past.