Brain evolution: new light on old principles.
The fossil evidence on the evolution of brains and bodies in mammals shows that there has been a progressive increase in relative brain size accompanied by and correlated with increased diversity among species in relative brain size. Small-brained species have also evolved, but more large-brained species have appeared in successive epochs.
D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000033:anatomy & histology*; D002335:Carnivora; D008322:Mammals; D010163:Paleontology; D010527:Perissodactyla; D013045:Species Specificity