What the Hell is Thylacosmilus?! 

Dude, seriously, your presentation style is great. You do such a great job of explaining things in a way that non-paleontoligists can understand, and at the perfect speed; not too fast and not too slow. You know when to pause and define the jargon and its not condescending. If you're not a professor, you should be!

Hello from Alaska! Love your content! I learn something new every time I watch your videos! Keep up the fantastic work!

I had a thylacosmilus fursona a few years ago!!!! Im glad to see that there are more people who love this incredible unique animal too :D

I'm thinking of the tusked deer, where their tusks essentially replace their horns, but they are principally herbivores. Probably not, but it should be considered.

You might want to look into your statement about triangular blades. While a triangular wound is more dificult to stitch, compared to a wound made by a flat blade. it was nothing a field surgeun couldn't handle. The real benefit of them was the ease with wich they could be produced, and the strength it had when stabbing. Making it less likely it would bend or break. Damage wise; a flat, serated, blade used with a twisting motion will make more ragged, irregular shaped, wounds. (In extention, a Fuller is a way of making a blade lighter, and not a "blood-gutter", as many suppose.)

I love this series

I always heard it was some sort of marsupial.

Maybe it was eating ants, grubs, termites or maggots. Or fish.

So the cat on ice age was one of these, the chin looks like it.

7:28 Imagine if we had teeth like that. Jesus, removing rotten teeth would be a pain in the ass. Same with removing wisdom teeth.

Would it be possible to de extinct this group somehow?

i fucking hate these things in ark. always getting off my flyers n shit

The study by Janis et al. that argued Thylacosmilus was a scavenger made that conclusion by taking its data out of context; a more recent study (Melchionna et al, 2021: search up “A method for mapping morphological convergence on three-dimensional digital models: the case of the mammalian sabre-tooth”) found it really was convergent with sabretoothed cats after all. Most of the features that supposedly indicated it was a scavenger and not acting like sabretoothed cats were actually also found in sabretoothed cats: these similarities only seemed to be differences between Thylacosmilus and sabretoothed cats due to Thylacosmilus having taken these features up another notch, and because the scavenger paper by Janis et al. failed to compare both Thylacosmilus and Smilodon to a non-sabretoothed carnivore to put their features in context (for example, Smilodon is capable of a far greater degree of cranial depression compared to Panthera, though not to the extent of Thylacosmilus; this is something Janis et al. failed to realize due to not comparing sabretoothed and non-sabretoothed carnivores in the way Melchionna et al. did, and disproves their argument that Thylacosmilus had adaptations for cranial depression more indicative of scavenging that true sabretoothed predators like Smilodon lacked). In addition, there’s reason to think that Thylacosmilus actually did have a full set of incisor teeth. Aside from the fact the premaxillary section of Thylacosmilus isn’t actually known from fossil remains (it was just assumed they were toothless there, hence all the skull models with missing incisors), wear patterns on the canines indicate they did have incisors between them. So unfortunately….this video is quite inaccurate when it comes to how this animal functioned. Also, because people are going to bring this up: South American predators like sparassodonts, sebecids and terror birds didn’t actually get outcompeted by placental carnivores like canids and felids. All three of the major South American predator clades entered chronic decline in the Late Miocene, with the sebecids already going extinct at this point. Thylacosmilus was the last sparassodont and died out before the Great American Biotic Interchange happened, as did all of the larger terror birds save Titanis (which actually evolved in North America and thus coexisted with placental competitors for its entire existence-it was its ancestor that moved into North America from South America). There were no large South American terror birds (and very few small terror birds) or any sparassodonts left by the time cats, canids, etc finally showed up in South America towards the tail end of the GABI.

Might I add that Smilodon had exceptionally big infraorbital foramina, even for felids. Maybe it has to do with using more numerous and/or more sensitive vibrissae to sense where to deliver the killing bite(as their canines were fragile to lateral stress).

You always do a marvelous job! A great topic would be comparing Thylacosmilus, Thylacoleo and some of the saber cats, what amazing convergence yet so many differences in morphology, anatomy, etc. Thanks RC

it literally had pockets, for its teeth. awesome

Dinosaur man has returned from the lands of dinosaur knowledge to share. Praise to the dinosaur man! Many thanks for your service you bring to the community. Very high quality Dinosaur content

It's actually not a war crime to use triangular bayonets. The Geneva Convention apparently prohibits _serrated_ bayonets, but not triangular ones.

I don't know about Thylacosmilus being a scavenger because it ate soft tissues. I rather think it was maybe a mid range predator not really capable of defending it's kill, like a cheetah. Scavengers tend to have stronger jaws for getting into tougher meat and bones of left over kill sites.

Interesting, Cheetahs focus on soft organs (somewhat) like Thylacosmilus, yet Cheetahs are no scavengers, they lose their prey to scavengers; strange.

Can you do a video on Therocephalians like Gorynychus, Trochosaurus, and Moschorhinus? The big ones have always been interesting predators to me. Also Theriodonts specifically the Gorgonopsid Rubidgea?

A scavenger does not usually get to find a dead animals soft organs lying there waiting for them. These are usually the first parts of the body that are consumed by whatever killed it. So I think there is a problem with the hypothesis you present in which thylacosmilus was A: a scavenger and B: consumed only the soft meats.

The scavenging hypothesis doesn’t make sense to me since most other scavengers evolve to deal with tough meat and bone. How often would you find an unguarded carcass that hadn’t already been scavenged? The soft tissue goes first. It seems pretty clear that it was an attack predator and perhaps like the cheetah took the best parts and moved on. South America had a number of heavy Carnivores that could have driven it from kills and lots of relatively slow large mammals that it’s large teeth would be useful in killing quickly with a bite to the throat.

This is just great! You did a superlative job! I have been following you for some time now and so enjoy your channel. A supporter, Kirk

How would it scavenge if it needed soft tissue? Scavengers don’t get first dibs with the nice soft bits; they need to scrape and crush bones.

5:15 To the best of my knowledge spike and triangular bayonets are not banned or a war crime to use and never were. The idea that they are is a persistent myth. Perhaps because you could make an argument for them falling under cause undue suffering rules. But in practice no one ever has, and bayonets are increasingly irrelevant. The 1949 Geneva Convention forbids *serrated* bayonets but doesn't mention triangular ones at all.

Callaghan, 🦖🇨🇳 Ancient eggshells show Dinosaurs already dying out before asteroid strike, Chinese scientists say.

I may have missed the part but I bet ya it specialized in something , like lynx to bunny’s ; and that food source disappeared cause of agw haha

I always thought that those giant daggers were used like PITON SPIKES to spike and hang on causing horrible bleeding then bringing up there back Claws like leopards disimbowling there soft belles then munching those lungs livers and stuff. And legging it. But Big Smilodons. Had rear crushing teeth. So hung around kills munching the Tough muscle. Hmm most don’t people don’t realise. ( imagine a RAW shoulder of A SHEEP ( we cook it softer Etc ) but imagine even with sharp teeth. Tearing at a large muscle that’s full of tendons tuff veins Etc. You can’t tear away this meat quickly. You have to HUNKER down take your time chewing . Humans did not cook meat to avoid PARASITES ETC. that was an unforeseen bonus. They cooked it because human teeth cannot really tear of meat from “ say “ a large deer or god forbid a MAMMOTH. Wether we found this out after FOREST FIRES following the ash track.Eating anything left that was edible Or we started these fires. All before we put a hunk of meat under the flame. Imagine a primative would think meat under the flame belonged to the flame gods. Or all these other imagination. I think most anthropologists have got a lot of PRE HUMAN HUNTING EATING RELIGIONS ETC. BACKWARDS. . Imagine a primative world. THUNDER ROLLS LIGHTNING STRIKES FIRES STARTS GIANT TREES BURN. .. left. Over a gifts from the gods: spirits / watever. Maybe they didn’t eat these half cooked animals at first beliving they belonged to the Gods. But really hungry ones took the risk. And the rest is history . Ok. My vague version

14:25, 14:45, 14:55 - or it was a long distance exhaustion chase predator, running its prey to exhaustion then getting out of there before the sprint predators and heavy carrion eaters arrived at the kill.

8:10 afaik cats have rough tongues so that they can rasp tissue off of carcasses - could thingamajig have had a de facto radula?

I'm curious about the paws and lung capacity of the Thylo as those k-9's would be ideal for catching fish.

😑 this is the face I make every time someone says a terrestrial animal was an absolute scavenger

Fantastic video. Many thanks. Please release a video on homotherium using similar data. It was a generalist predator and quite successful, and it's extinction doesn't make sense.

Boy oh Boy the back half looks like a TASSIE tiger.

In 2020 I was a thylacosmilus for Halloween

You come over as a really good man. Probably battled with a speech impediment in younger life was probs bullied but your love for your subject and that you and your partner found each other both with similar Careers and love of Interesting Fossils bones creatures Etc. God bless . I always watch your presentations and Your wifes. Always intresting. And of course I’m subscribed. But I don’t have monies in UK to donate sadly. But your Blogs/ Vlogs ?? Lol. Are on my list. If I came into monies. Lol. All the best. ROGER from LONDON . 😇

Very cool video! To be honest I always thought Thylacosmilus was just a marsupial. Nice to learn more about it.

Another excellent video. Thanks for all the time, effort and enthusiasm you put into each one!

What a brilliant video of a fascinating mammal that has no really close living relatives! The description of the animal including the FEA of its skull comparing it to Smilodon and giving pointers why it evolved that way and objectively detailing the reasons it went extinct were highlights. As regards the post orbital bar, I am an engineer who has dealt occasionally with stress analysis of engineered structures. Even in them, it has always struck me how introducing even small, seemingly inconsequential details, can have a big effect on how stress can be reduced in a structure which also has the effect of reducing local deflections which may be nowhere near these details.

looks more related to a possum or jackel, than a cat really

Really interesting. A Gene Simmons tongue? Did you add music to the end or did Brilliant? LOVE IT.

love your vids, but aside from tiny things, the only dedicated scavengers are flying creatures; ie vultures. predators & omnivores are usually scavengers, sometimes they might even do quite a bit of it, but there ain't no evidence for a "primary" scavenger among medium or large land animals. Frankly, it's NONSENSICAL to bother suggesting it. Maybe they were scavengers like lions or wolves. Which nobody calls scavengers. The "soft parts" feeding actually works strongly AGAINST scavenging, too, as the soft/easy bits are generally the first things others will eat (even in your cheetah example...the soft parts are gone when the hyena or lion comes along). Anyway, that silly scavenger talk triggers me. I am struggling to figure out what would be enjoying the abundant left-overs Thylo is leaving though. I doubt it's terror birds (although they might drive them from a kill). Do we have any powerful jaws & teeth among sparasadonts or marsupials of the time & place? reptiles or birds if not?

It looks like a giant ferret to me

Most Australians (like me) know about Thylacenes, & a whole bunch of us also know something on the "Marsupial Lion", Thylacaleo...but Thylacosmilus? This is news to me (God - I love RU-vid! So much obscure-variety!)...very comprehensive analysis. BUT, my understanding is the elongated-canines of Smilodon have been shown (by research & experimentation) to be far too fragile for using in actual hunting or fighting, & were likely reserved for delivering the "coup-de-gras" to exsanguinate a prey-animal (thru the jugular) AFTER the pack has already subdued the prey. Seems a bit overkill to me, but hey! Cats, right?

You said it was like nothing else we've ever had. Sounds like it was sort of like the Cheetah now, though. Still, a fascinating video, thanks! Here's a like and comment for the Almighty Algorithm!

BTW I thumbs upped you and subscribed. Love that your making the video and I'm just adding my 2 cents to the discussion. Not trying to throw shade on your endeavor here. Good job👍

This was put together and delivered fantastically. Well done man!

The tooth of thyloacosmilus is much more like a medieval rondel dagger than the smilodon's. The rondel dagger was largely used by late medieval knights and men at arms to kill other knight and men at arms, in an era where suits of full plate armour were being employed. It really seems these are armour defeating teeth. That and a possibly large muscular and prehensile tongue makes this thing sound like the terror of armadillos and other armoured xenarthrens!

Im getting really annoyed with this awfully common conclusions. In 90% of cases if an animal was a predator and they couldnt figure out how it hunted they say it was a scavenger... and if it went extinct it's because of climate change...

15:21 Interesting Mammoth design. 2:27 comparable to Jaguar. 11:28 Post-Orbital bar. Gives a more pronounced protected structure.

This is what happens when God gets off shrooms and just says you know what I'm going to experiment and say f*** it I'm going to throw a bunch of animal parts together and see what I come up with thus this thing was born they ask God so what do you call this thing God :🤔good question ⁉️

14:30 ff: If Thylacosmilus was a scavenger, why did it have the saberteeth? If we compare them to cheetahs which are definitely hunters, the mere scavenger hypothesis doesn't really make sense.

Nah I reckon it was an armour penetrating dagger toothed armadillo offal slurper. Getting in and out before the angry birds arrived.

Ecosystems within ecosystems within ecosystems. A single cell is an ecosystem. An animal body is an ecosystem. A tree is an ecosystem. From the atomic to the infinite. Can you imagine ecosystems? A seventeen-mile-long mycelium living underground in France is an ecosystem linking, symbiotically, the entire forest as one organism.

From the day I saw this animal in my encyklopedia during childhood, Thylacosmilus stayed in my mind to this day. And I have never found such a great video, like yours, dedicated to this animal. Thank you sir ! I am also fascinated by these strange marsupial not marsupial mammals. Sometimes I think about, what if, due to convergent evolution, some marsupial developed as highly as for example chimpanzee or another higher ape :D

If the theory is it was a scavenger that fed primarily on the soft parts of a carcass, why did it have a skull that could handle greater lateral stresses than a predator such as Smilodon? Perhaps it fed on small prey items that were still large enough to necessitate being subdued after capture.

Its too big to ever just feed on carrion. Also we dont have a complete skull every skull we have is missing the very front so we dont even know if it did not have front teeth. Like cats and dogs it could have used it molars to get food. Scraping with the side of its face. Most of the time when to see a lion getting meat off a bone its using its molars not its front teeth.

That speciation - diversity part just made me think of the human species: if decline in speciation and diversity is what portends extinction, Homo sapiens is in that path.

Metatherians became extinct in South America but their marsupial relatives maintained and increased their diversity and are still with us today.

From watching a lot of these videos, everything either involves into crabs, cats, or flying creatures

Am I the only one that thought Thylacosmilus looked like a wolf and not a cat?

Well, with the prefix Thylaco it gives an instant impression it's a marsupial.

Thank you for your presentation. I appreciate your hard work.

I notice the eyes are framed (as you say) and the resultant field of vision is not as good a later placentals.

Count up the metatherians to find out if the smiladon is a jedi

This is the first time I have seen your work. I am really impressed. I like the detail about HOW we know (provisionally) these things.

triangle blades are not a warcrime, they are just better at penetrating armor for the most part and are actually easier to stitch up

Such incredible design. Thank you for the comparison.

This animal has possibly the most unique diet fir a terrestrial vertebrate period

Awesome vid! Love sabertoothed animals 💗

There is a bit of this presentation that was a bit worrisome. Around the 17:00 minute marker the presenter starts talking about how a lack of new speciation while a reduction in diversity is happening means your group is getting closer to extinction. That seems awfully ominous if you apply that same logic to the Homo family... EDIT: By the way, awesome video on Thylacosmilus. It's hands down the best one I've seen on this fascinating beast on RU-vid so far.

The soft organ theory is both amazing and very disturbing.

Stop saying Pubic. It's not PewBic. It's a pouch, pocket, or simply pelvis. Be creative, and say the function of what it does.

It was basically a Smilus which got Thylacolised.

So I'm a toe walker like I always walk on my toes and balls of my feet I can't control it I've seen a bunch of docs the said it's an Achilles tendon thing but does that make me a digitegrade

So glad I found your channel this is so awesome 😎

What makes Smilodon so mysterious is it’s hunting style many theorize it was a bite and follow kind of predator using its teeth to wound its prey and follow it until it bled to death which would explain why it’s teeth aren’t designed to shake and kill prey.

Really cool animal and great presentation!

thylacsmilus looks like a cross between a rodent and a marsupial, possible genetic relation in its genetic lineage branch relation to marsupials and rodents

From what you describe of it’s teeth and mouth, these are stabbing teeth, then it was a stabbing hunter, slurping up blood rather than chewing meat. Think of what we see of big cats biting at the neck, imagine if this thing kept stabbing till it cut an artery to bring blood to the surface.

this change many of the things I though of this species I always thought oh it was the saber tooth of its land but now seen it as a probably mainly scavenger makes me think what other predator where present to take the " apex " place if it wasn't Thylacosmilus could it be hoove crocodiles and terror birds ? south America sure was a weird place in prehistoric times

I wish you'd talked more about what those lower jaw droops, whatever the technical term for that is, but otherwise a fascinating video.

Perhaps they ate toitoise's or something armoured

Underapreciated, this channel is cool, i have never guess what thylacosmilus was doing

Just gonna throw this out there: another group of mammals that lack maxillary anterior teeth are insectivores like anteaters, aardvarks, and armadillos. Those large canines could have been used to tear into termite mounds and ant nests, then the large tongue (another insectivore trait) could have been used to lap them up. Competition from these other insectivores could have been their downfall. South America has anteaters, armadillos, and peccaries; all of which eat insects. It's tempting to characterize animals with large canines as carnivores, but that's not always the case.

Is that Wesley Crusher from Star Trek?

giant beaver. The teeth are for cutting wood.

It's wierd how many times Saber teeth evolved on cat built animals first Nimravids then [Barbourofelidae is disputed]Thylachomimus and then the felines like Smilodon

Thylacosmilus was mewing alot

Excellent video! As a aspiring paleozoologist , I love learning with you.

Convergent evolution : A group of unrelented animal sharing similar traits

Put music in the background dammit

There are atleast 2 large marsupial carnivores, both in Thylacoleonidae. These are Thylacoleo carnifex and Wakaleo alcootaensis.

This was so interesting. Great presentation.

Would the extinction criteria with regard to speciation apply to us, humans, as well? Seeing as we're the last of the hominins and are not diversifying our species, despite having such a large number of individuals.

So it was a stabby, blood/organ sucking vampire kitty?

The thylacine may be making a come back.

Here after the recent eye orientation paper 🍿😎

I never suspected Thylacosmilus could be this interesting (or rather the science behind it).