Archaeothyris

Archaeothyris Temporal range: Upper Carboniferous
Archaeothyris
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Superclass:	Tetrapoda
Class:	Synapsida
Order:	Pelycosauria
Genus:	Archaeothyris
Species:	A. florensis
Binomial name
Archaeothyris florensis Reisz, 1972

Archaeothyris was one of the earliest definite synapsids. It lived in the late Carboniferous period, 306 million years ago.^[1]

It shares this fame with another species (Echinerpeton) about which little is known. Protoclepsydrops is even slightly older, but only fragments have been found.

Archaeothyris was found in Nova Scotia, in the same area as several other species which were probably sauropsids: Hylonomus, and Petrolacosaurus.

Archaeothyris belonged to a group of early pelycosaurs which evolved early in the Pennsylvanian. It is thus seen as the precursor of all synapsids (which include mammals).

1. ↑ Falcon-Lang H.J; Benton M.J. & Stimson M. 2007. Ecology of early reptiles inferred from Lower Pennsylvanian trackways. Journal of the Geological Society, London, 164, #6. 1113-1118