It may seem that mostly land-dwelling even-toed ungulates such as giraffes and deer have little in common with exclusively aquatic whales and dolphins. However, recent scientific evidence suggests that cetaceans may have evolved from even-toed ungulate ancestors. Shared origins can now be seen within the fossil record, with early cetaceans possessing a specialised ankle bone that brings together Cetacea and Artiodactyla into a mammalian superorder, Cetartiodactyla. This groups the largest animal ever to have lived (the blue whale) together with the tiny, 2kg mouse deer.
Scientific name: Cetartiodactyla
An evolutionary tree for the group of mammals known as Cetartiodactyla. When the evolution of mammals is analysed, some surprises emerge - such as the fact that hippos and deer share a common ancestor with whales.
Discover what these behaviours are and how different plants and animals use them.
Additional data source: Animal Diversity Web