Viverrids are the most primitive of all the families of feliform Carnivora and clearly less specialized than the Felidae. In external characteristics, they are distinguished from the Felidae by the longer muzzle and tuft of facial vibrissae between the lower jaw bones, and by the shorter limbs and the five-toed hind foot with the first digit present. The skull differs by the position of the postpalatine foramina on the maxilla, almost always well in advance of the maxillopalatine suture, and usually about the level of the second premolar; and by the distinct external division of the auditory bulla into its two elements either by a definite groove or, when rarely this is obliterated, by the depression of the tympanic bone in front of the swollen entotympanic. The typical dental formula is: , but the number may be reduced, although never to the same extent as in the Felidae.