Jackals are medium-sized omnivorous mammals of the genus Canis, which also includes wolves, coyotes and the domestic dog. While the word 'jackal' has historically been used for many small canids, in modern use it most commonly refers to three species: the closely related black-backed jackal and side-striped jackal of sub-Saharan Africa, and the golden jackal of south-central Eurasia, which is more closely related to other members of the genus Canis.Dog Gray wolf Coyote African golden wolf Golden jackal Ethiopian wolf Dhole African wild dog Side-striped jackal Black-backed jackal Jackals are medium-sized omnivorous mammals of the genus Canis, which also includes wolves, coyotes and the domestic dog. While the word 'jackal' has historically been used for many small canids, in modern use it most commonly refers to three species: the closely related black-backed jackal and side-striped jackal of sub-Saharan Africa, and the golden jackal of south-central Eurasia, which is more closely related to other members of the genus Canis. Jackals and coyotes (sometimes called the 'American jackal') are opportunistic omnivores, predators of small to medium-sized animals and proficient scavengers. Their long legs and curved canine teeth are adapted for hunting small mammals, birds, and reptiles, and their large feet and fused leg bones give them a physique well-suited for long-distance running, capable of maintaining speeds of 16 km/h (9.9 mph) for extended periods of time. Jackals are crepuscular, most active at dawn and dusk. Their most common social unit is a monogamous pair, which defends its territory from other pairs by vigorously chasing intruding rivals and marking landmarks around the territory with their urine and feces. The territory may be large enough to hold some young adults, which stay with their parents until they establish their own territories. Jackals may occasionally assemble in small packs, for example, to scavenge a carcass, but they normally hunt either alone or in pairs. The English word 'jackal' dates back to 1600 and derives from the French chacal, derived from the Persian شغال shoghāl, which is in turn derived from the Sanskrit सृगाल sṛgālaḥ meaning 'the howler'. Similarities between jackals and coyotes led Lorenz Oken, in the third volume of his Lehrbuch der Naturgeschichte (1815), to place these species into a new separate genus, Thos, named after the classical Greek word θώς 'jackal', but his theory had little immediate impact on taxonomy at the time. Angel Cabrera, in his 1932 monograph on the mammals of Morocco, questioned whether or not the presence of a cingulum on the upper molars of the jackals and its corresponding absence in the rest of Canis could justify a subdivision of that genus. In practice, Cabrera chose the undivided-genus alternative and referred to the jackals as Canis instead of Thos. Oken's Thos theory was revived in 1914 by Edmund Heller, who embraced the separate genus theory. Heller's names and the designations he gave to various jackal species and subspecies live on in current taxonomy, although the genus has been changed from Thos to Canis. The wolf-like canids are a group of large carnivores that are genetically closely related because they all have 78 chromosomes. The group includes genus Canis, Cuon, and Lycaon. The members are the dog (C. lupus familiaris), gray wolf (C. lupus), coyote (C. latrans), golden jackal (C. aureus), Ethiopian wolf (C. simensis), black-backed jackal (C. mesomelas), side-striped jackal (C. adustus), dhole (Cuon alpinus), and African wild dog (Lycaon pictus). The latest recognized member is the African golden wolf (C. anthus), which was once thought to be an African branch of the golden jackal. As they possess 78 chromosomes, all members of the genus Canis (coyotes, wolves, jackals) are karyologically indistinguishable from each other, and from the dhole and the African hunting dog. The two African jackals are shown to be the most basal members of this clade, indicating the clade's origin from Africa. Canis arnensis arrived in Mediterranean Europe 1.9 million years ago and is probably the ancestor of modern jackals. The paraphyletic nature of Canis with respect to Lycaon and Cuon has led to suggestions that the two African jackals should be assigned to different genera, Schaeffia for the side-striped jackal and Lupulella for the black-backed jackal or Lupulella for both.