Thylacosmilus at first glance looks much like the famous Smilodon (sabertooth tiger)... This animal is very far removed from Smilodon, it is not even a placental mammal. It is a metatherian (marsupials are the living metatherians) more closely related to kangaroos, koalas, wombats, etc than to the saber-toothed tiger.What puzzled me was that prominent flange angling downward on the front of the mandible (apparently serving to "protect the large canines", presumably from lateral blows). But I'm not sure with the flange there how the saber-canines can penetrate the victim's flesh (?).
The similarity between Thylacosmilus and Smilodon is an excellent example of convergent evolution - two distantly relating forms converging upon a simular morphology and life habitat. There are an three other examples of mammals that have developed saber-teeth- in fact most of the last 65 million years had some large cat-like saber-toothed mammal present, the modern biota is the outlier.
Thylacosmilus went extinct roughly 3 million years ago, closely coinciding with the formation of the land bridge linking the Americas. Animals from North America emigrated south and those from South America journeyed north; this fauna exchange is referred to as the Great American Interchange. It is at this time we start to find Smilodon fossils in South America. It is thought that the arrival of this relatively larger predator (the largest Smilodon was twice the size of the largest Thylacosmilus) may have been what drove the only known marsupial saber-toothed form to extinction.
From Your Daily Fossil, via Fauna and A London Salmagundi.
Addendum: re the discussion in the comments re the function and efficacy of these saber teeth, here's a 3D rendering of the critter from The Alchemy Works (with a hat tip to Lady Aritê gunê Akasa):
I think you are going with the assumption that it's a meat eater.
ReplyDeleteMany people would assume Gorilla's were also carnivores from the immense size of the animal and large sharp teeth...
That's a good thought. Walruses (and I think boars) use their tusks to root in the ground.
Delete"ground" = seabed
DeleteThe flanges would be out of the way when it opened its mouth to bite. They come off the bottom of the chin and curve away from the front of the mouth, so they're never forced inward toward whatever's been bitten into. The teeth would only be alongside the flanges after the jaws had closed enough for them to overlap. Does this picture help? http://thealchemyworks.com/images/Thylacosmilus.jpg?osCsid=ah0j2oekriurlkmsjl88bdr1b4
ReplyDeleteIt does help some, but even so, it looks like there's maybe a couple cm of clearance between the tooth tips and the lower jaw - hardly enough to take a meaningful bite out of an opponent or prey. A modern wolf's dentition would be more fearsome in my view.
DeleteStill pondering.
(but's it's a good pic - I'll append it to the post. Tx.)
(reversed the image to facilitate comparison with the skull)
Being a marsupial, I would guess it could gape it's jaws like the Thylocine. It would open it's mouth really wide and bite into the neck of a much larger prey animal.
ReplyDeleteWhile I'm less well-versed on Thylacosmilus [I know the carnivoran sabertooth morphs - felids and nimravids - much better], elongated canines generally come with jaw modifications to allow for an exceptionally large gape. Smilodon could open it's jaws 120 degrees, compared to a lion's 60. [http://en.wikipedia.org/wiki/Smilodon#Teeth_and_jaws]
ReplyDeleteWho the hell decided to call it a bloody smilodon? Yeah we get it but its too damn childish. Not good enough!
ReplyDeleteYou do understand that the etymology is from Greek words meaning "chisel" + "tooth", right?
DeleteWhy is that childish?
Maybe it could rest its head on the protuberance like a monopod when its mouth was closed, gazing out at the world, but not chipping the tips of its teeth. Or whatever.
ReplyDeleteTasmanian Tiger ( http://en.wikipedia.org/wiki/Thylacine ) - now extinct subject of current film "The Hunter" - in case anyone is interested in modern descendants of this critter.
ReplyDeleteReminds me of a marriage of rodent teeth, always growing due to perpetual wear, together with ram horns, for head-butting rival males. I have to say, though, the hinge point of the lower jaw seems terribly "off", as regardless of its preferred meals the bottom molars would meet the top molars at least somewhat evenly for chewing; they way they are set in this display, they do not meet. A professional would be able to extrapolate the shape of the missing bottom molars, and knowing what shape those took would tell us much more about what this creature ate. Come to think of it, setting the bottom jaw so it is not at that strange 15 degree angle to the upper teeth would give more of a visual clue as to the purpose of that fascinating front flange. It won't sign my AIM name btw, CinnaLaPoete@aol.com.
ReplyDeleteIf I recall correctly, Thylacosmilus had those long lower mandibular flanges to protect its fangs (naturally), but those same fangs, unlike those of the smilodonts, machairodids, meganteriids nimravids or other sabertoothed mammals, kept growing throughout the life of the creature. Thus, if a fang got chipped/broken, it would eventually grow back again. One indicator of this is the two humps over the eyesockets. Those were actually casings for the deep roots of the fangs.
ReplyDelete. . . oops; my netID is Guodzilla (titanicdoug6@yahoo.com).
ReplyDelete