Fossil record
Fossil record
In addition to the three extant species, some fossil zebras have also been identified. Equus koobiforensis is an early zebra or equine basal to zebras found in the Shungura Formation, Ethiopia and the Olduvai Gorge, Tanzania, and dated to around 2.3 mya.[21]
E. oldowayensis is identified from remains in Olduvai Gorge dating to 1.8 mya. It is suggested the species was closely related to the Grévy’s zebra and may have been its ancestor.[33] Fossil skulls of E. mauritanicus from Algeria which date to around
1 mya appears to show affinities with the plains zebra.[34][35] E. capensis, known as the Cape zebra, appeared around 2 mya and lived throughout southern and eastern Africa and may also have been a relative of the plains zebra.[36][33]
Non-African equines that may have been basal to zebras include E. sansaniensis of Eurasia (circa 2.5 mya) and E. namadicus (circa 2.5 mya) and E. sivalensis (circa 2.0 mya) of the Indian subcontinent.[21] A 2017 mitochondrial DNA study placed the Eurasian E. ovodovi and the subgenus Sussemionus lineage as closer to zebras than to asses.[37]
