Description

Jaguars
The fossil jaguar differs from the sabertooth cat, Smilodon, in several ways as well. Most obviously, P. onca does not possess the large saber-like upper canines of Smilodon (Figure 4). The canines of the jaguar are rounder and more conical in shape. The coronoid process of the mandible (Figure 3A) is also taller in the jaguar than Smilodon, and the deciduous carnassial teeth of Smilodon and Panthera onca have been compared in some detail, and have been found to be diagnostically different (Kurtén, 1965 )
Fossils of Panthera onca may be differentiated from fossil pumas (Puma concolor) based on characters of their ankle bones. The ectal facet, or one of the contact surfaces between the astragalus and calcaneus on the astragalus, is narrower and posteriorly pinched in the puma (Figure 5). In addition, the sustentacular facet, the other surface of contact between the astragalus and calcaneus on the astragalus, is more posteriorly drawn than the puma. The astragalar neck is also relatively shorter in Panthera onca compared to Puma. While difficult to observe from Figure 5, pumas also generally have larger feet than jaguars of similar size (Kurtén, 1965).