Sexual dimorphism in Equus

Sunday 25 December 2011 by Véra Eisenmann

The main and commonly known sexual dimorphism in Equus is the presence of well developed canines at least on the maxillar in males and the almost constant lack of canines in females.

Moreover, the pubian symphysis is flatter in females after their first parturition.

Concerning the limb bones dimensions, the dimorphism is weak, too weak to discriminate male and female bones inside any sample. Even if the average dimensions are slightly larger in males, the largest dimension may well belong to a female (fig.3 in 142.Early Pleistocene equids (Mammalia, Perissodactyla) of Nalaikha (Mongolia) and the emergence of modern Equus. ).

The attached diagrams comparing males and females were done on an anterior limb bone (MC III) and a posterior one (talus) in a species where the male is territorial (E. grevyi) and another living in family groups (E. hemionus onager).