Friday mystery object #347 answer

Last week I gave you these teeth to have a go at identifying:


It was a bit mean of me to only show the incisors, but I thought it would be way too easy otherwise and I thought that some of you would manage to get it. I was not wrong.

Despite the sparse information, James Bryant, Jennifer Macaire, Allen Hazen, sallie reynolds, Michelle Tabencki, Kaitlyn, Rémi and a tentative few others leaned towards one of the sabre-toothed cats, with most people opting for Smilodon. That is indeed what these teeth belonged to and if you want to be specific they’re from Smilodon fatalis Leidy, 1869.


Reconstruction of Smilodon fatalis skull. Image by Bone Clones, 2000

The mystery specimen and I go way back as it’s the one in the Geology Department of Bristol University, where I did my undergraduate degree many years ago. It inspired me to do a project on Smilodon, which sent me around a variety of UK museums in search of specimens to measure.

That was the start of my behind-the-scenes experience in museums and I met some fantastic people, including the legendary Andy Currant at the NHM, London, who was so helpful, knowledgeable and welcoming that it left an indelible mark on my attitude to collections access and curation.

I still have a soft spot for Smilodon and of all the palaeontological questions that I’d love to see resolved it’s how their bizarre canines worked. I never considered the “Akersten canine-shear-bite” [opens as pdf] as being biomechanically plausible, not least because it requires the jaws to close during the bite, which would in turn require these incisors to penetrate the skin and some (or all) of the underlying tissue of the prey.

While these incisors are robust, they’re just not the right kind of shape for that type of action as the straight and fairly level row would dissipate force quite evenly during a bite, rather than allowing the high point loads well suited to penetration.

There are other, more plausible methods proposed (e.g. Brown, 2014), but without seeing Smilodon in action it’s one of those mysteries that may never be satisfactorily resolved. And who wouldn’t want to see something as terrifying as a gigantic, sabre-toothed feline in action?

Smilodon californicus and Canis dirus fight over a Mammuthus columbi carcass in the La Brea Tar Pits. By Robert Bruce Horsfall, 1913

Smilodon californicus and Canis dirus fight over a Mammuthus columbi carcass in the La Brea Tar Pits. By Robert Bruce Horsfall, 1913


14 thoughts on “Friday mystery object #347 answer

  1. Lovely stuff, as always, Paolo. I presume options considered (and rejected?) include sexual display, walrus style use, etc? That is, instead of thinking of them as canines, could we think of them as tusks? Could they even be male specific? How would we know?

    • A big give-away is the presence of serrations. You can’t see them unless you look closely, but the enlarged canine tooth has a definite cutting edge that only really makes sense as a functional feature. Plus, at Rancho La Brea there are over a thousand Smilodon specimens preserved and none lack the canines (except through obvious breakage or loss).

  2. Silly thought and question time – do you think it could be because of the thick fur on the prey at the time – imagine having to bite down through twelve inches of fuzz before reaching any flesh. I was thinking the canines developed during the ice age – then, when things warmed up or they moved south following prey, the teeth became more and more of a liability. Well – just some thoughts. But I’d like to know, because I’m starting a new time travel book, lol.

        • I think we might also consider the modern Clouded Leopards of South and Southeast Asia, which have the largest canines for their size of any modern cat: almost as large, proportionally, as Smilodon’s. It makes their faces very bulky, with almost cuboid snouts, but they don’t seem to have problems with breakages, albeit, since the teeth are in absolute terms smaller, the forces on them are less.

          • I can picture a very compact, front-heavy animal that would use its disproportionately large and strong forelimbs to grip its prey while biting – the strong grip would keep its head still and limit the risk of breaking teeth on a struggling animal. Seems to imply it would attack from above though?

            • As James Bryant’s link suggests, that would be close to Smilodon’s technique – except it brings its prey down and then bites, so doesn’t need to attack from above. Clouded leopards, on the other hand, are extremely arboreal so, despite their fangs, are otherwise quite lightly built and stalk and ambush on or from branches (so yes, they DO attack from above).

              I really don’t know what clouded leopards need those canines for but they tend to go for prey smaller than them (wild fowl etc) or up to their size (feral dogs, say, or, I think, forest deer).

              I know I started this idea, but I have no idea where I am going with it. Ulp…

        • Smilodon canines took a long time to grow in, with the milk sabres not fully emerging for a year to a year and a half (before being shed), with the adult sabres emerging inside them and thus quite well protected while the young animal learned to use them. These adult sabres then took another couple of years to reach full size. This is unusual for big cats and it doesn’t apply to the rest of Smilodon‘s dentition, so apart from the slower growth expected for large teeth, there’s considerable training time to learn to use them effectively and reduce breakage risk.

          Plus, there was a lot of tooth breakage, but Smilodon was likely a cooperative hunter based on density of remains in Rancho la Brea (similar to dire wolves rather than Panthera atrox and the various bears which were all presumably solitary hunters), so there was probably some sharing of prey with incapacitated or less efficient animals in the pack.

  3. Pingback: Friday mystery object #348 answer | Zygoma

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