Evolutionary history Cynodont

thrinaxodon triassic of south africa

together extinct gorgonopsians , therocephalians, cynodonts part of group of therapsids called theriodonts.

the oldest , basal cynodont yet found charassognathus (late permian). other basal cynodonts procynosuchids, family includes procynosuchus , dvinia. cynodonts among few groups of synapsids survived permian–triassic extinction event , had slow recovery after extinction.

the derived cynodonts found within clade eucynodontia, contains members of mammalia. representative genera of nonmammalian cynodonts include large carnivorous cynognathids, equally large herbivorous traversodonts, , small mammal-like tritylodontids , ictidosaurs. presence of respiratory turbinates suggests rapid metabolism , possibly endothermy.

during evolution, number of cynodont jaw bones reduced. move towards single bone mandible paved way other bones in jaw, articular , angular, migrate cranium, function parts of mammalian hearing system.

cynodonts developed secondary palate in roof of mouth. caused air flow nostrils travel position in of mouth instead of directly through it, allowing cynodonts chew , breathe @ same time. characteristic present in mammals.