Biogeographic evolution of Equidae
Hyracotherium evolved in North
and the greatest diverisity of equid fossils is also North American.
"Cone of Diversity" in this conventional portrait of
evolution implies that Equid diversity has increased steadily over
whereas it actually depicts only the recent vicariance
in evolutionary time) of
Equus. The genus reached South America,
Asia, and Africa (zebras) only very recently, but died out everywhere
the Old World. Horses were re-introduced into North America by
in the 16th century.
Text material © 2005 by Steven M. Carr