What put the “slink” in a saber cat? Scapular and pelvic adaptations enhance stealthy stalking behavior in Smilodon fatalis (17.2)

Mammalian carnivores generally belong either to pursuit or ambush hunting categories. Prey capture requirements for each method differ, and these strategies generally correlate with familial taxonomic levels. Canidae tend toward pursuit, while most Felidae specialize in ambush. The extinct saber‐tooth, Smilodon fatalis, is considered an ambush predator because it is large bodied, robustly muscled and short limbed. These attributes limit this cat’s ability to move sinuously, and therefore act as a constraint on hunting postures. Also, no characters have been identified that enhance Smilodon’s adaptations for concealment while stalking prey. This study of a sample of the typically unassociated limb and limb girdle elements from the asphalt deposits of Rancho La Brea reveals morphological features derived from unique pectoral and pelvic adaptations that improve this cat’s ability to move with great flexibility. Reoriented scapular and truncated ilial shapes give Smilodon a lower crouching profile than is shown by other felids. Usually, in a slinking cat, the posterodorsal aspect of the scapula and the anterodorsal ilial region project above the vertebral spinous processes. In contrast, in Smilodon , with fore and hind limbs flexed to a degree equal to other cats, the shoulder and hip regions fall below the spinous processes, enhancing the cat’s ability to flatten its body to facilitate concealment while stalking prey.