There are three caballine crania from the Irvingtonian (300 BP?) of Hay Springs, Nebraska.
E. niobrarensis, Hay 1913, type skull UNSM 4999
I have studied only a cast of the type; Azzaroli mentioned the original appeared to have been heavily reconstructed.
E. hatcheri, Hay 1915, type skull (...)
I consider as certain ‘Caballines’ fossils in which cranium, and upper cheek teeth, and lower cheek teeth have caballine characters.
1. According to Azzarroli (1998) the first caballine in North America may be represented by the right mandible UNSM 93078, a fragmental jaw UNSM 93082, and two MT (...)