|1st Species||Archaeothyris florensis|
|Time Range||306 mya|
|Location||Canada, Czech Republic, United States of America|
|Name Meaning||Ancient window|
|Physical Dimensions||50 centimeters long|
Archaeothyris is an ophiacodontid pelycosaur synapsid from the Pennsylvanian of Canada, Czech Republic, and the United States of America. It was named in 1972 by Robert R. Reisz. It was one of the oldest synapsids, and despite being primitive, it was more advanced than early sauropsids.
Archaeothyris resembled the generic monitor lizard. It was a reptile with 4 legs, a long tail, a broad body, and a long head with mid-sized jaws. It body would have been covered in scaly skin.
Archaeothyris was a predator, preying on insects and other arthropods. Its jaws had small and sharp teeth designed for catching arthropod prey, as well as for crushing them.
Not much is known about Archaeothyris, although it can be inferred that it lived very similarly to modern lizards, quickly scampering across through the swampy terrain and eating arthropods whenever it was hungry, as well as climbing up trees and hiding in fallen logs in order to escape hungry predators.