Indohyus: the fox-sized leap that started whale evolution
Indohyus was a small, fox-sized, semi-aquatic mammal from the Eocene whose whale-like bones link it as the closest non-whale relative to cetaceans. Fossils and later research place it at the base of the whale lineage (Whippomorpha), preceding Pakicetus and other early whales as land-dwelling artiodactyls gradually adapted to an aquatic lifestyle, a transition driven by ecological pressures and climate shifts about 45 million years ago.
