Mammals failed to develop a neocortex.
Mammals are any vertebrates within the class Mammalia -LRB- -LSB- mÉ™ËˆmeÉªli.É™ -RSB- from Latin mamma #Latin `` breast '' -RRB- , a clade of endothermic amniotes distinguished from reptiles -LRB- including birds -RRB- by the possession of a neocortex -LRB- a region of the brain -RRB- , hair , three middle ear bones and mammary glands .
Mammals
failed to develop
a neocortex
the possession of