On the Prowl by Mark Hallett

Author:Mark Hallett
Language: eng
Format: epub
Tags: SCI027000, Science/Life Sciences/Evolution, SCI054000, Science/Paleontology
Publisher: Columbia University Press
Published: 2020-06-01T16:00:00+00:00

FIGURE 5.12. Jaguar footprints in a cave.

A few sheltered caves in the midwestern United States and in central Europe have beautifully preserved footprints of large ice-age pantherins like jaguars and steppe lions from when they padded across the soft sediments. Source: Photo by Bob Osburn.

Natural Trap Cave in the Bighorn Mountains northeast of Lovell, Wyoming, is a 26 m (85 ft.) sinkhole cave that preserved a rich diversity of Late Pleistocene and Holocene mammals, ranging from packrats to mammoths, over the millennia, and the talus slope underneath the hole preserved not only a fully complete, articulated skeleton of an American lion (Panthera atrox) but also bones representing several individuals of the American cheetah (Miracinonyx trumani). This is the only site in which the American cheetah is known from more than one specimen. The American lion specimens from Natural Trap provided a valuable assemblage for comparison with that of Rancho la Brea and are featured in a 2009 paper by H. Todd Wheeler and George T. Jefferson that assessed the proportions, sexual dimorphism, and behavior of P. atrox.

During the Late Pleistocene, the huge American lion successfully penetrated as far south as Chilean Patagonia in South America. In northern South America it was an apex predator, sharing this role with the jaguar Panthera onca, the puma Puma concolor, and the massive dirk-toothed sabertooth Smilodon populator. At one particular locality, the Cueva del Milodón, near Última Esparanza in Chilean Patagonia, northwest of Puerto Natales, the preservation of some lion remains, as described in a 2017 paper by the researchers Nicolas R. Chimento and Federico L. Agnolin (both Museo Argentino de Ciencias), offer a unique glimpse of how this species may have looked and possibly even behaved in life. The remains (originally reported by Lehmann-Neitsche in 1899 and incorrectly assigned to an extinct jaguar, “Panthera onca mesembrina”) include pieces of fur-covered, mummified skin “adhering to the ‘face’ (maxilla?) and forelimb,” as well as an isolated phalanx with preserved keratinous claw. The color of the skin patches, as reported in a paper by Roth (1904) is “a reddish brown tone (rufous), a color that constituted the background of available skin patches from the limbs and body.” Although it isn’t clear whether Roth refers to the color of the fur or the skin, the coat hairs as preserved are in actuality a light tan color. Roth further speculates that this “indicates that the species probably exhibited dark and some yellowish color stripes, at least in the forelimbs.” The same cave preserved several skulls of the ground sloth Mylodon with deep tooth gouges in the posterior parietal region. These indicate an attempt to rend away the temporalis muscles as a food source, most likely by a large felid like P. atrox. There was also a coprolite (fossilized fecal mass) that contained a large number of Mylodon dermal ossicles.

In 1997 L. A. Borrero reported another fossil site near Cueva del Milodón, which he described as a deep cave and “burrow” that contained a bone accumulation of large mammal

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