The teriodontes or teriodontos are named after the huge size and could reach the teeth of some of its species, mainly carnivorous, the Late Triassic had led an organization very similar to that of mammals. The temporal fossa was widening to allow the accommodation of large jaw muscles so that the hole reached the parietal and squamosal bones and postorbitario no longer be above it, and finally, the bar itself postorbitaria was incomplete leading to the typical mammalian condition in which the orbit and temporal fossa are fused.
The teriodontes or teriodontos (Theriodont, gr. "Beast's teeth") are a clade of therapsids ( "reptiles" mammal) that lived from the Permian to the Cretaceous.
This group was characterized by the lower jaw articulates with the skull bone in the small square by looking through powerful muscle bundles that made possible a wide range of yawn, making possible the emergence of species with huge teeth, as was the case of gorgonópsidos, the first known saber-toothed.
The special importance of this bone is not his presence, but its evolution along the jaw bone, which eventually forming the chain of middle ear bones of mammals. However, there is no evidence of secondary palate. The forelimbs are extensible and later also have the ability to erect posture.
The Theriocephaly, which started its development almost simultaneously to gorgonópsidos, also had additional features similar to mammals, as is the number of phalanges of the hand and foot, with a formula of 184.108.40.206.3, typical of mammals and that is what continues to hold the primates, including humans.