An analysis of megafauna remains from Argentina reveals sabre-toothed cats could crunch through bones, reshaping views about their supposedly weak sabres.
The study focuses on the bones of several large South American herbivores uncovered from Salto de Piedra, which lies about 350 kilometres south of Buenos Aires. Prior work has uncovered the skeletons of an abundance of large animals from the site, including giant armadillos, giant land sloths, mastodons and sabre-toothed cats like Smilodon populator. The site is one of the only robustly dated Pleistocene localities in Argentina, allowing researchers to thoroughly track its animal populations over time.
Sabre-toothed cats 鈥� represented by the genus Smilodon 鈥� frequented the area between 22,200 and 13,300 years ago.聽Traditionally, these animals were thought to have weak teeth. The extra-long canines 鈥� which could stretch over 25 centimetres in length 鈥� were an evolutionary trade-off, the thinking went, that gave an added ability to puncture flesh but diminished durability if they hit harder bits of bone beneath.
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鈥淧ersonally, I always found that interpretation difficult to accept,鈥� says at the Argentine Museum of Natural Sciences, who wasn鈥檛 involved with the research. 鈥淚t seemed unlikely that such a large predator would evolve enormous canines only to avoid using them.鈥�
In the new work, at the Museum of Natural Sciences in Madrid, Spain, and her colleagues analysed the bones for signs of predation. Their survey focused on two kinds of tooth marks across the bones: punctures and grooves. They measured the length, width, and depth of the markings using digital calipers, then aligned the marks with known Smilodon teeth.
The results revealed that markings on several of the megafauna matched the cat teeth perfectly and that hard cortical bone, which comprises 80 per cent of bones, was broken.
鈥淲e were all surprised,鈥� says Fernandez-Jalvo. 鈥淭he conical tooth mark of the fossil bone matched perfectly in size and shape with the Smilodon large canines.鈥�
The study provides some of the clearest direct evidence of how Smilodon interacted with its prey, says Agnol铆n, helping palaeontologists recognise Smilodon predation in the fossil record with much greater confidence.
鈥淭he new evidence reinforces the idea that Smilodon was capable of penetrating cortical bone with its canines, leaving distinctive marks without causing apparent damage to the teeth,鈥� he adds. 鈥淭his strongly suggests that the sabres were mechanically much more robust than traditionally believed.鈥�
BMC Ecology and Evolution
