Characteristics
All extant feliforms share a common attribute: their auditory bullae (bony capsules enclosing the middle and inner ear). This is a key diagnostic in classifying species as feliform versus caniform. In feliforms the auditory bullae are double-chambered, composed of two bones joined by a septum. Caniforms have single-chambered or partially divided auditory bullae, composed of a single bone.
The specific characteristics of extant feliform bullae suggest a common ancestor, though one has not been identified in the fossil records. There are other characteristics that differentiate feliforms from caniforms and probably existed in their stem taxa. But due to speciation these do not apply unambiguously to all extant species.
Feliforms tend to have shorter rostrums than caniforms, fewer teeth, and more specialized carnassials. Feliforms tend to be more carnivorous and are generally ambush hunters. Caniforms tend more toward omnivorous and opportunity-based feeders.
Many feliforms have retractile (retractable) or semi-retractile claws and many are arboreal or semi-arboreal. Feliforms also tend to be more digitigrade (walking on toes). In contrast, most caniforms are terrestrial, have non-retractile claws and tend to be plantigrade.
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