Adapids (members of the taxon Adapidae) are a diverse group of extinct primates that primarily radiated during the Eocene epoch between about 55 and 34 million years ago. However, one specialized endemic Asian group (sivaladapines) survived into the Miocene. Fossils of adapids are known from North America, Europe, Asia, and Africa. Adapids are one of two groups of Eocene primates with a geographic distribution spanning holarctic continents, the other being the omomyids (Omomyidae). Early representatives of the Adapidae (e.g., Cantius and Donrussellia) and Omomyidae (e.g, Teilhardina and Melanerimia) are some of the earliest known crown primates.