Paleontologists from the University of Texas at Austin and elsewhere have discovered a fragmentary jaw of the scimitar-toothed cat Homotherium on McFaddin Beach, Texas. This is the first occurrence of Homotherium from the continental shelf of the Gulf Coast. That landscape may have formed a broad subtropical Gulf Coast corridor that facilitated the dispersal of Neotropical species along the coast between Texas and Florida. The associated fauna from McFaddin Beach contains Neotropical mammals common to southern Texas and Florida and indicates that Homotherium was a member of the fauna inhabiting the Gulf Coast corridor during the Late Pleistocene.
Homotherium serum. Image credit: Sergiodlarosa / CC BY-SA 3.0.
Homotherium is an extinct genus of scimitar-toothed cat that inhabited Americas, Eurasia, and Africa during the Pliocene and Pleistocene epochs from around 4 million to 12,000 years ago.
These animals were large, robust cats about the size of a jaguar, with an elongated face, lanky front legs, and a sloping back that ended in a bobtail.
Their serrated canine teeth were covered by large gum flaps, similar to domestic dogs today.
Their fossils have been found in several areas of Texas, but the newly-discoverd fossil shows for the first time that the big cat roamed the now-submerged continental shelf that connects Texas and Florida.
“This stretch of land was a Neotropical corridor,” said University of Texas at Austin doctoral student John Moretti and his colleagues.
“Animals such as capybaras and giant armadillos that wouldn’t have ventured farther north used this strip of humid grassland to move from Mexico to Texas to Florida.”
In this fossil specimen of Homotherium studied by Moretti et al., two teeth are visible breaking out at the bottom: an incisor, and the tip of a partially-erupted canine. Scale bar – 1 cm. Image credit: Sam Houston State University.
The fossil studied by the team was discovered more than 60 years ago on McFaddin Beach, south of Beaumont, by at Lamar University’s Professor Russell Long.
“The fossil looks like a lumpy, rounded rock with a couple of exposed teeth that are a little worse for wear, having been submerged and tumbled along the floor of the Gulf of Mexico for thousands of years before washing up on a beach,” the researchers said.
“But when the fossil was X-rayed, we saw there was more to the fossil that met the eye: a hidden canine tooth that had not yet erupted from the jaw bone.”
“It was just what we needed to identify the fossil as belonging to a Homotherium, a genus of large cat that roamed much of the Earth for millions of years.”
“Because this specific cat wasn’t fully grown when it died, its distinctive saber-like canine tooth had not fallen into its permanent position. Nestled inside the jaw, the tooth was protected from the elements.”
“Had that saber tooth been all the way erupted and fully in its adult form, and not some awkward teenage in-between stage, it would have just snapped right off,” Moretti said.
“It wouldn’t have been there, and we wouldn’t have that to use as evidence.”
“The discovery that Homotherium lived along this corridor gives scientists a small glimpse into the ecology of this landscape during the Late Pleistocene,” he added.
“Big carnivores such as these cats helped shape the broader animal community, tamping down prey-animal populations and influencing regional biodiversity.”
The results were published in The Anatomical Record.
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John A. Moretti et al. The scimitar-cat Homotherium from the submerged continental shelf of the Gulf Coast of Texas. The Anatomical Record, published online April 23, 2024; doi: 10.1002/ar.25461
Source : Breaking Science News