Summary

1. In East Turkana, at Koobi Fora, inside levels about 1.9 My old, were found remains of a very large Allohippus : A. koobiforensis. The patterns of its upper and lower cheek teeth were different from usual Allohippine patterns.

At the same time there lived at Koobi Fora a smaller monodactyl equid, probably an Allohippus because of its short protocones, usual in this genus. The gracility of the limb bones referred to this ?Allohippus sp. and their similarities with extant E. africanus suggest adaptation to dry conditions.

2. Inside levels about 1.5 My old, were found fossils resembling Allohippus koobiforensis but much smaller.

From the same levels were collected a few upper cheek teeth possibly belonging to the ?Allohippus sp. of old levels.

Other fossils of the same age remain incertae sedis. Some resemble Asses, many - small Grevy zebras.

3. Inside younger levels (MC zone, around 1My ago) were found two very different forms : one resembling Sussemiones by the marked plications of the teeth enamel, the other resembling ?Allohippus sp. or Wild Asses.

4. From the Guomde Formation come very plicated teeth, possibly indicating humid conditions.

5. The associated upper and lower cheek teeth from the Galana Boi Formation could belong to an extant E. grevyi or E. burchelli.

6. A large E. burchelli was possibly present in the MA zone. E. burchelli was certainly present in the MC zone.