Five skulls remain unclassified using this kind of ratio diagram (Unclassified 1).
Unclassified fragments. Fifteen other skulls were too fragmentary to be studied by this kind of ratio diagram (Unclassified 2).
Dinohippus and Pliohippus
Dinohippus 11724, 87201, and Pliohippus 12998 have similar proportions (Dino-Plio 1) but only the last one has a well developped POF.
Five other skulls are all different (Dino-Plio 2).
B-1. Thirteen skulls referrable to Cormohipparion B, differ from the group A mostly by their longer naso-incisival notches. They tend also to have longer muzzles and shorter palates.
B-2. Two skulls are similar but quite smaller.
B-3. Five skulls have a long muzzle.
B-4. One skull (...)
A-1 : Height adult skulls and two juveniles may be easily referred to Cormohipparion A. They are characterized by relatively long palates (2), wide muzzles 15), and short naso-incisival notches (NNI=30).
A-2 : Sixteen skulls are similar but smaller, and have a deeper naso-incisival (...)
As the variation is the largest for measures of the fossa, especially its distance from the orbit (’bar’ : mesure 32), I have drawn separate ratio digrams for other dimensions : 5=post-palatal length ; 23=anterior ocular line ; 2=palatal length ; 1=muzzle length ; 15=maximal muzzle breadth ; (...)