Mention a sabertoothed cat and most people think of Smilodon. But this apex predator was a strictly New World cat.
The other Pleistocene sabertooth – Homotherium – ranged over all the northern continents, as well as Africa and possibly parts of South America. (Antón; Rincón and others; Turner and others)
It definitely was the more successful of these two sabertooths, but it’s also more of a mystery.
Paleontologists debate Homotherium’s origins and how many species it had, but perhaps their biggest question is how it used its legs.
Unlike Smilodon, which had short legs and a massive body, Homotherium resembled a modern lion, probably without the mane, but with long, graceful legs. This was in addition to the typical sabertooth features of powerful forelimbs, a long neck, and a short back. (Antón)
Those muscular front legs were somewhat longer than a lion’s. This gave Homotherium a hyena-like body shape, especially in North America, where these cats had a very short back and hind legs (Antón), as shown in the image at the top of this post.
Paleontologists don’t know why Homotherium evolved this way. No modern cat has a locomotion setup like this, so the experts can only theorize over it.
Some think that the long legs and associated features mean that Homotherium hunted on open ground, while Smilodon probably lurked behind cover and ambushed its prey. (Turner and others)
Bolstering this view are Homotherium’s less retractile claws – a feature which cheetahs also have. (Antón)
Not everybody is on board with this, but no one argues with Turner and Antón when they write that ” . . . the appearance of Homotherium suggests something unique among the cats.”
Maybe someday we will figure out what made “the other ice-age sabercat” so special.
Featured image: Skb8721 at the English language Wikipedia. CC BY-SA 3.0.
Antón, M. 2013. Sabertooth. Bloomington: Indiana University Press.
Rincón, A. D.; Prevosti, F. J.; and Parra. 2011. New saber-toothed cat records (Felidae: Machairodontinae) for the Pleistocene of Venezuela, and the Great American Biotic Interchange. Journal of Vertebrate Paleontology. 31(2):468-478.
Turner, A., and M. Antón. 1997. The Big Cats and Their Fossil Relatives: An Illustrated Guide to Their Evolution and Natural History. New York: Columbia University Press.
Turner, A., Antón, M., Salesa, M. J., and Morales, J. 2011. Changing ideas about the evolution and functional morphology of Machairodontine felids. Estudios Geológicos. 67(2): 255-276.