|About the Book|
Over the past 30 million years felids have remained hypercarnivorous, eating almost nothing but vertebrates. Although much attention has been paid to phylogeny and comparisons of diet among groups in the Carnivora, little attention has been paid toMoreOver the past 30 million years felids have remained hypercarnivorous, eating almost nothing but vertebrates. Although much attention has been paid to phylogeny and comparisons of diet among groups in the Carnivora, little attention has been paid to the interfamilial differences in felid diets. In this study, linear morphometrics of the crania, mandible, dentition and forelimbs were used to explore the association between shape and prey size among living felids. To accomplish this, felids were divided into three prey-size groups: (1) large prey specialists that generally kill prey their own size or larger- (2) small prey specialists that take prey smaller than themselves- and (3) mixed prey feeders that kill a variety of prey sizes depending on what is preferred or available. Felids that kill prey near or above their own body size can be distinguished from those that take prey smaller than themselves by their relatively robust canines, both in the mediolateral and anteroposterior dimensions, relatively wide muzzles, relatively more robust humeri and radii, relatively larger distal ends of the humerus, relatively larger articular areas of the humerus and radius, relatively longer olecranon processes of the ulna, wider proximal paws and body mass that exceeds 21 kg. All of these osteological features help to withstand the forces placed on the skull and skeleton when subduing and killing larger prey. These morphometric techniques worked well on extant cats, and would most likely work well on extinct conical toothed cats, and possibly even enigmatic sabertoothed cats as well. Additionally, radiographs were used to measure the cortical thickness of the humeri of 28 species of living felids, 20 species of living canids and the extinct species Smilodon fatalis and Canis dirus. There were no significant differences in cortical thickness between the two families, but as shown in chapter 2 differences in their prey-killing styles are displayed in their external osteological structures, such as sites for muscle attachments and external robustness of the forelimbs. Humeral radiographs did show anomalously thick cortical bone present in the extinct saber-toothed cat, Smilodon fatalis, which may have important implications for how these extinct cats captured and killed their prey.