The Living Hyaenas
Although once the hyaenid lineage contained a large number of species, only four members of the family persist on earth today. Click on a species' name to find more information about it.
- Brown hyaena (Parahyaena brunnea)
- Striped hyaena (Hyaena hyaena)
- Spotted hyaena (Crocuta crocuta)
- Aardwolf (Proteles cristata, formerly Proteles cristatus)
These animals are very important and influential inhabitants of most African and some Asian ecosystems. Hyaenas arose in the warm, moist, forested habitat that covered most of Europe, Asia, and Africa during the Early Miocene. The earliest fossil hyaenids are specimens found in France dating to c. 18 MYA (Werdelin & Solounias 1996). Recent work by Koepfli et al. (2006) suggests the relationships among the extant hyaenids indicated in the phylogenetic tree below (Figure from Watts & Holekamp 2007).
Hyaenas are medium to large in size, 10-80 kg. They have a bushy tail, and three of the four species have stripes or spots on their coats (the brown hyaena is the exception). The ears may be either rounded or pointed. The aardwolf has five toes on each foot whereas the other hyaenas have only four. A mane may be present. The forelegs are longer than the hind legs so that the back slopes downwards to the base of the tail. Their stance is digitigrade and their claws are blunt and non-retractile. A unique feature of the hyaenids is the presence of anal pouches, which the animals evert to mark objects within their territories with odoriferous secretions. Anal pouches are also well developed in the related viverrids and herpestids. Hyaenids lack a baculum.
The three species of bone-cracking hyaenas are characterized by massive jaws and large premolars and molars used to crush bone. The cheekteeth of Proteles are small and peg-like, although its canines are sharp and fairly large. The incisors of hyaenids are unspecialized, except that the third incisor on each side is larger than the others. The dental formula of Proteles is 3/3, 1/1, 3/2-1, 1/1-2 = 28-32; that of other hyaenas is 3/3, 1/1, 4/3, 1/1 = 34. The skulls of extant hyaenids also lack alisphenoid canals, and their auditory bullae are divided, although the septum is not easily visible.