アナウサギ
Originally assigned to the genus "Lepus", the European rabbit was consigned to its own genus in 1874 on account of its altricial young, its burrowing habits, and numerous skeletal characters. It is superficially similar to the North American cottontails ("Sylvilagus") in that they are born blind and naked, have white flesh, and little sexual dimorphism. However, they differ in skull characteristics, and cottontails do not habitually construct their own burrows as the European rabbit does. Molecular studies confirm that the resemblance between the two is due to convergent evolution, and that the European rabbit's closest relatives are the hispid hare, the riverine rabbit and the Amami rabbit. The oldest known fossils attributed to the modern European rabbit species are around 0.5 Ma old (Middle Pleistocene).