299-252 million years ago
In the lower jaw, therapsids possessed a reflected angular, a coronoid
process, and their jaw joint was located more anteriorly. Therapsids reduced
the number postcanine teeth and the canine teeth became further enlarged.
There was a reduction in the number of incisors to 5 upper and 4 lower
incisors in therapsids. The postcanine teeth increased their complexity.