Characteristics Cynodont

bienotherium yunnanense

early cynodonts have many of skeletal characteristics of mammals. teeth differentiated , braincase bulged @ of head. outside of crown-group mammals (notably therians), cynodonts laid eggs. temporal fenestrae larger of ancestors, , widening of zygomatic arch in more mammal-like skull have allowed more robust jaw musculature. have secondary palate other primitive therapsids lacked, except therocephalians, closest relatives of cynodonts. (however, secondary palate of cynodonts comprises maxillae , palatines in mammals, whereas secondary palate of therocephalians comprises maxillae , vomer.) dentary largest bone in lower jaw.

the cynodonts had form of warm-blooded metabolism. has led many reconstructions of cynodonts having fur. being endothermic may have needed thermoregulation, fossil evidence of fur (or lack thereof) has been elusive. modern mammals have harderian glands secreting lipids coat fur, telltale imprint of structure found primitive mammal morganucodon , onwards. nonetheless, recent studies on permian synapsid coprolites show more basal therapsids had fur, , @ rate fur present in mammaliaformes such castorocauda , megaconus.

marks in upper , lower jaw of cynodonts has been interpreted channels supplied blood vessels , nerves whiskers. whiskers may have been typical of cynodontia whole, or have evolved in group.

derived cynodonts developed epipubic bones. these served strengthen torso , support abdominal , hindlimb musculature, aiding them in development of erect gait, @ expense of prolonged pregnancy, forcing these animals give birth larval young in modern monotremes , marsupials. placentals, , perhaps megazostrodon , erythrotherium, lose these.

cynodonts known synapsid lineage have produced aerial locomotors, gliding , flying being known in haramiyidans , various mammal groups.