Detailed descriptions of each studied cranium are long and tiresome.
I have drawn Simpson’s ratio diagrams for each cranium and observed that, fortunately, most caballine crania fall approximately into one of the following groups.
1. Horse from Jaurens : on the diagram the largest (relative to E. hemionus onager) value is the muzzle width (measure n°17).
2. Horse from Siréjol : the largest values are the Vomer-Basion lenth (n°4), the palatal length (n°2-5), and the muzzle width (n°17).
3. Horse from Valdichiana : the largest values are the Vomer-Basion lenth (n°4), and the muzzle width (n°5).
4. Horse from Voijn : The largest value is the palatal length (n°2-5).
5. Horse from Kotelny : Largest values are palatal length (n°2-5), and least muzzle breadth (n°17bis).
6. Horse from Avenches : the latrgest value is the Vomer-Basion lenth (n°4).

In the Cranial morphs Table are listed crania that can be assigned to each of these groups.