The most well known ancient big cat was probably from North America. Smilodon fatalis, also known as the Saber-toothed Lion (or “Diego” from the Fox film Ice Age, for those of us who enjoy talking animals), was long thought to have migrated from Europe or Asia to the New World, where it eventually died out 11,000 years ago. But recent research shows they probably didn’t cross over to the New World; saber-toothed cats originated here.

A new analysis of fossils that were collected over the past 25 years in Polk County, Florida, shows that saber-toothed cats have been around the Americas for a lot longer than we had thought. First discovered in a phosphate mine in 1990, these fossils originally were so incomplete that researchers were unsure they pointed to any conclusive evidence about saber-toothed cats. But recently, a donation from Florida resident Barbara Fite shed light on previously discovered fossils. The donation included a specimen with a well-preserved jaw and teeth. Steven Wallace, leader author of the study and associate professor at East Tennessee State University, analyzed this specimen and compared the jaw morphology to that of other saber-toothed cats. He found that the jaw structure of the new species was somewhere in between older saber-toothed cats and ones that appeared later in the fossil record.

Wallace and his team determined that the fossils belong to a cat similar to Smilodon, aptly named Rhizosmilodon fiteae. Rhizosmilodon means “the root of Smilodon,” and fitae pays homage to the donator, Barbara Fite. Wallace and his associates think that Rhizosmilodon is the missing link between Smilodon fatalis and much older lineages. The Rhizosmilodon fossils are 5 million years old, 2.5 million years older than the oldest Smilodon fossils.

Rhizosmilodon fitae represents one of the oldest lineages among about 20 different saber-tooth cat species that have yet been discovered. Paleontologists hope that further analysis of saber-tooth fossils will reveal more about the often-puzzling Smilodon ancestry.

Find out more about this new saber-toothed cat species at sciencedaily.com.

You can read Wallace’s study in the journal PLOS ONE.

The Paleontological Research Institution, Ithaca, New York, is pleased to sponsor Paleontology content for This View of Life. Founded in 1932, PRI has outstanding programs in research, collections, and publications, and is a national leader in development of informal Earth science education resources for educators and the general public.


Published On: March 20, 2013

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