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A quick, crappy doodle of Thylacosmilus.

Thylacosmilus is one of the more widely-known of Pliocene mammals (which in itself isn’t saying much). This is primarily due to it being used as a case study for convergent evolution, given that it had large saber-teeth like the more famous Smilodon, yet was completely unrelated to it. It was actually a marsupial, despite its incredibly catlike appearance.

One of the truly bizarre things about Thylacosmilus is that its lower jaw has two flanges projecting directly underneath its saber-teeth. I have reconstructed those here as being covered in skin “sheathes” for the sabers, but it is still entirely possible that the teeth would have been exposed in life. I simply drew what I believe to be the most plausible explanation.

(If you spot any glaring inaccuracies in either the drawing or the writeup, please let me know. I always welcome an opportunity to learn something new!)

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Following my drawing a few months ago where I drew my take on Spinosaurus Aegypticus after a groundbreaking fossil discovery altered our perception of them, I decided to draw my take on thylacosimus following a recent fossil discovery altered our perception of them. :D Thanks to @cartoon-and-animal-lover for inspiring me to draw this. ;)

It has been discovered that Thylacosimlus was NOT a sabre tooth predator, as it’s teeth were too soft to feast on rough meat, it lacks incisors and their jaws are not completely fused together. This gave the creature a pretty weak bite, so a lot of people are theorising on what they may have eaten as a meat eater that had such a weak bite. :o With me personally, I have a theory they may have used their teeth to scrape away at the flesh/open up carcasses and slurp up the entrails of cadavers, but there are numerous theories going around so I’m interested to hear what your theories are. :D…

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Bet you didn’t see that one coming. I actually posted something!
And this something is a lippy Thylacosmilus atrox, because why not?
Plants are modern South American ones, because I couldn’t really find anything useful about Pliocene S. American flora.

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Final for Thylacosmilus atrox. In the 1920s Captain Marshall Field funded two expeditions to South America which were undertaken by the Field Museum of Natural History in Chicago, Illinois; these expeditions were launched under the hopes of finding fossils of mammals and other animals from the Cenozoic Era. In 1926, during the second expedition, a team was searching the Ituzaingo Formation in northern Argentina when they came across the remains of three animals thought to be never before discovered species of ancient marsupial. 

South America was prime real estate when it came to new discoveries due to it having been almost completely cut off from the rest of the world since the beginning of the Cenozoic and so expectations were high when it came to finding some uniquely adapted mammal specimens, it wasn’t until 1933 when paleontologist Elmer S. Riggs named and described the specimens found on the Marshall Field Expeditions that science would realize just how right they were about the mammals of that time and place.

Thylacosmilus (meaning: “Pouched Knife”), was a member of member of a group called Sparassodonta, once thought to be true marsupials it is now considered to be a closely related group. Despite their resemblance to later placental predators like Smilodon fatalis, they were not closely related to them at all. Their saber teeth are an example of convergient evolution, where different, unrelated species develop similar traits to fill similar niches. Unlike felids, it’s teeth grew backwards into their skull the older they got, they also did not possess retractable claws like most cats. Due to their short legs it’s likely T. atrox were ambush hunters.

It was roughly 4.9 feet in length and weighed around 330 pounds and it lived during the Late Miocene to Pliocene, roughly 9 to 3 million years ago.

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i’m crying…. the size comparison chart for Thylacosmilus on Wikipedia has fucking sherlock as the human model

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Scientific name: Thylacosmilus atrox
Diet: Herbivorous mammals, with some supplemental fruit
Projected natural lifespan: 20 years
Length: 1.2 meters (4 feet)
Weight: 80 kg (176 lbs)
Locality: Northern Argentina; 9-3 Ma (Miocene-Pliocene)
Exhibit: South America

Thylacosmilus is one of the largest and last of the sparassodonts, a group of South American predators closely related to marsupials. It has two large saber-like teeth in the upper jaw - but unlike those of saber-toothed cats, they’re rooted far back in the skull. The lower jaw has a pair of flanges at the front that shield the saber teeth. Thylacosmilus has a relatively low bite force, instead using its powerful arms and neck to force prey into submission.

At Huxley
Thylacosmilus can be found in the Cenozoic South America section. One of our younger Thylacosmilus is an ambassador animal - you can visit him at the Anning Paleontological Museum on weekends!

Notable Behavior
We have three adult Thylacosmilus that we rotate through the exhibit areas. Although we gave them the opportunity to interact with each other, they did so rarely. A lot of times, when they see each other, they do what we think is a territorial display: they will open the jaws wide - up to almost 110 degrees! - and show off the saber teeth. They all use the same areas of their enclosures as a latrine, including where they mark territory.

Like the incisor teeth of rodents, the saber teeth of Thylacosmilus never stop growing through their life. In order to keep the teeth at a manageable size, we give them lots and lots of things to chew on, from durable rubber toys to rawhide and bones. They’re very good at destroying things.

Keeper Notes
Have you ever been licked by a Thylacosmilus? They have huge tongues and they drool. A lot.

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Looking to learn all I can about the Thylacosmilus. Please pm me or tag me in any posts you find or if you know alot and wanna share with me.

Also wanting to learn about animals they lived with, preys, predators, etc

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Convergent evolution was up to its tricks again with today’s entry the thylacosmilus

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Thylacosmilus has a really weird skull! Especially their weird little eyeholes!

But most drawings Ive seen tend to cover up most of the weirdness with fleshy bits and fur and just make it look like sort of a cat.

So I did this in sort of a “shrinkwrapped” style, so you can see how weird it is!

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