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. A 2017 mitochondrial DNA study placed the Eurasian E. ovodovi and the subgenus Sussemionus lineage as closer to zebras than to asses. Hybridisation Fertile hybrids have been reported in the wild between plains and Grévy's zebra. Hybridisation has also been recorded between the plains and mountain zebra, though it is possible that these are infertile due to the difference in chromosome numbers between the two species. Captive zebras have been bred with horses and donkeys; these are known as zebroids. A zorse is a cross between a zebra and a horse; a zonkey between a zebra and a donkey and a zoni between a zebra and a pony. Zebroids are often born sterile with dwarfism. Characteristics As with all wild equines, zebra have barrel-chested bodies with tufted tails, elongated faces and long necks with long, erect manes. Their thin legs are each supported by a spade-shaped toe covered in a hard hoof. Their dentition is adapted for grazing; they have large incisors that clip grass blades and rough molars and premolars well suited for grinding. Males have spade-shaped canines, which can be used as weapons in fighting. The eyes of zebras are at the sides and far up the head, which allows them to look over the tall grass while feeding. Their moderately long, erect ears are movable and can locate the source of a sound. Unlike horses, zebras and asses have chestnut callosities present only on their front legs. In contrast to other living equines, zebra have longer front legs than back legs. Diagnostic traits of the zebra skull include: its relatively small size with a straight profile, more projected eye sockets, narrower rostrum, reduced postorbital bar, separation of the metaconid and metastylid of the tooth by a V-shaped canal and rounded enamel wall. Stripes Zebras are easily recognised by their bold black-and-white striping patterns. The coat appears to be white with black stripes, as indicated by the belly and legs when unstriped, but the skin underneath is black. Young or foals are born with brown and white coats, and the brown darkens with age. A dorsal line acts as the backbone for vertical stripes along the sides, from the head to the rump. On the snout