The Eurasian and North American Scimitar Cats may have been the Same Species

The scimitar cat roamed Eurasia and North America for millions of years until its extinction about 11,000 years ago.  This apex predator sported fangs and was about the size of a lion.  Evidence from Friesenhahn Cave in Texas suggests it preyed upon juvenile mammoths and mastodons as well as peccaries.  A study of bone chemistry in Europe indicates 1 specimen ate yaks.  The scimitar cat is not as well known as the more robust saber-toothed cat (Smilodon fatalis) that apparently was restricted to North and South America.  Another species of saber-toothed cat (S. populator) occurred in eastern South America.  Remains of scimitar-toothed cats are uncommon in the fossil record.  Entire skeletons were found in Friesenhahn  Cave, but elsewhere, if evidence is excavated of scimitar cat, it is usually just a single bone or tooth.  This reflects low populations compared to the prey species it fed upon.  Generally, large carnivores are less common at fossil sites than the species they depended upon for food because predators are necessarily less abundant than their prey.  This low population caused an huge gap in the fossil record of Eurasian scimitar-toothed cats.  There was no evidence of scimitar-toothed cats in Eurasia after 300,000 years BP until the jaw bone of 1 individual was netted by a fishing boat in the North Sea a few years ago. (Much of the North Sea was above sea level during Ice Ages.)  This new specimen dates to 28,000 years BP.  There is also 1 stone statuette that may or may not be of a scimitar-toothed cat–the identification is unclear.  Thousands of generations of this species lived on the continents of Europe and Asia, but this is all the evidence we have of scimitar-toothed cats living there during the late Pleistocene.

Illustration of scimitar cat.

This Pleistocene-aged stone statuette may be a representation of a lion or a scimitar-toothed cat.  The deep chin, evolved to protect the fangs, and the bob-tail are evidence it represents Homotherium.  However, the absence of fangs and straight back (Homotherium had a sloping back) indicate it represents a lion.  Unfortunately, this artifact was lost a century ago.

Scientists analyzed the DNA from the North Sea specimen and compared it with the DNA from specimens of scimitar-toothed cats from the Yukon, Canada and some specimens of South American Smilodon populator. They determined the lineage of scimitar-toothed cats (Homotheridae) diverged from the lineage of saber-toothed cats (Smilodontheridae) 18 million years ago.  Despite their similar convergent appearance they were about as closely related to each other as house cats are to tigers.  The genetic study also suggests the Eurasian scimitar-toothed cats (Homotherium latidens) and the North American scimitar-toothed cat (H. serum) should be considered the same species.  The authors of the study found “low genetic diversity despite wide geographical occurrence.”  However, the specimens the scientists used in the study were north and west of the ice sheet that cut most of North America off from Beringia and Eurasia.  Scientists need to study DNA from specimens south of the ice sheet to conclusively show H. latidens = H. serum. A previous genetic study of lions (Panthera spelea, P. leo, and P. atrox) determined North American lions south of the ice sheet were a different species than those north of it.

Reference:

Anton, Mauricio; et. al.

“Soft Tissure Reconstruction of Homotherium latidens (Mammalia, Carnivora, Felidae): Implications for the Possibility of Representation in Paleolithic Art”

Geobios  42 (5) 2009

Paijmans, Johanna; et. al.

“Evolutionary History of Saber-toothed Cats Based on Ancient Metagenomes”

Current Biology (in press)

 

Tags: Homotherium latidens, Homotherium serum