Skull proportions, excluding the size of the preorbital ‘bar’ (32) : Group A
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 notch.
A-3. Twenty one differ from the 16 precedent mainly by a smaller anterior ocular line and a shorter naso-incisival notch.
A-4. Six skulls are close to the precedent 21, but have the deepest naso-incisival notches.
A-5. Two are very small : Sheep Creek 69700 and Jonas Wilson 70108.
A-6. In this group of 10 specimens, palate and P2-M3 are long.
A-7. The palate seems especially long in the skull 613-150 from June Q. and in specimen 10864 from Leptarchus Q. referred to Neohipparion.
A-8. A wide muzzle characterizes three specimens.
A-10. Unclassified A. The last ratio diagram shows 6 skulls that could not be placed in any of the previous groups but all with short naso-incisival notches - a group A character. Most have wide muzzles, but not as wide as in Morph 8.