ABSTRACT
The Lagomorpha, or 'duplicidentate' rodents, are characterized by the presence of two pairs of gnawing incisors in the upper jaw. They first appeared in the Paleocene in Asia and thus seem to be of ultimate Old World origin, whereas the Rodentia may have arisen in the New World. All the Lagomorpha except the earliest primitive forms may be referred to one or the other of the two extant families, the Ochotonidae and Leporidae. The pika family has been in existence since the Oligocene. The main part of its history is confined to the Old World, mainly Eurasia, though stray forms have invaded Africa. In the Pleistocene, pikas entered North America. The Leporidae differ from the Ochotonidae in the development of long hind legs and long ears; they have three molars in the upper jaw, the pikas only two. The Beremend rabbit ranges from the Astian through the Villafranchian and Middle Pleistocene up to the C-Cromer.
