Exaeretodon is a genus of traversodontid cynodont; several species are known, from various formations. E. argentinus, E. frenguelli, and E. vincei are from the Carnian-age (Upper Triassic) Ischigualasto Formation of Argentina. E. major and E. riograndensis are from the Ladinian-age (Middle Triassic) portion of the Santa Maria Formation of Brazil. E. statisticae is from the Carnian-age Maleri Formation of India. This genus was an herbivore up to 1.8 meters long (5.9 ft), with a specialized grinding action when feeding.
An analysis of the size of the bones of calves collected in Paleorrota concluded that the mother Exaeretodon had one or two calves, for one pregnancy. Another point of interest is that these cynodonts had deciduous teeth, which is a characteristic of mammals and means that babies could not chew, and required specialized parental care. Only older juveniles had permanent teeth.
The Ishigualasto tetrapod assemblage (Late Triassic, Agentina) and 40AR/ 39AR dating of dinosaur origins. (argon dating of dinosaur remains in Argentina)
May 07, 1993; Dinosaurs originated sometime during the Middle to Late Triassic and rose to dominate terrestrial tetrapod communities by the end...