Hearted Youtube comments on Animal Origins (@animalorigins) channel.

  1. The Atlas mountains were once a wonderful mix of European and African species. There once was a subspecies? of aurochs, too, reddish in colour. Great video on a little known animal.
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  2. Elephant Babys are, objectively speaking, very cute!
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  3. Actually, sparassodonts IN GENERAL went extinct before placental competition could appear, not just Thylacosmilus. Thylacosmilus was the very last sparassodont (it was the only one to survive into the Pliocene), and it went extinct around 3 million years ago. The Great American Biotic Interchange had not happened at this point, so when carnivoran competitors entered South America later down the line they actually didn’t run into any sparassodonts to outcompete and displace (and few native predators period-only a few terror bird species were left, and most of those were small-bodied, Titanis being the only South American apex predator left by the time placental competitors showed up). Furthermore, South American predators in general had been in a chronic decline since the Late Miocene, losing much of their diversity even before the Pliocene. So it DIDN’t boil down to carnivorans outcompeting sparassodonts in the end. And the entire idea of placentals outcompeting metatherians is debatable, partially because this whole case study of “carnivorans outcompeting sparassodonts” never actually happened. Australia is not a good case study of placental mammals outcompeting marsupials, either: the biggest impact of placentals in Australia is actually predation by cats and foxes on small marsupials that they do not compete with, and Australian ecosystems were already heavily damaged by human activity before Europeans started bringing invasive species over, which skewed the tables in favour of invasive species (as a rule, successful invasive species are species that do well in damaged or disturbed ecosystems). Even the dingo vs. thylacine example is questionable, because it has been found that thylacines were much smaller than previously reported to be, meaning they were hunting much smaller prey than those regularly taken by dingoes, thus not resulting in serious competition. On top of that, rodents had already made it into Australia by the Pliocene and they didn’t end up outcompeting marsupials then.
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  4. How about Toxodon and th Notoungulates for a future video? I don't think I have seen anyone ever discuss them other than in passing. I don't know what defines the group, where it came from, or why it went extinct...
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  5. THYLACOSMILUS DID NOT FILL THE SAME NICHE AS SMILODON. This is a common misconception that unfortunately spreads faster than it can be corrected. While it would seem that they convergently evolved because "big canines" their skull anatomies are drastically different. For starters those famous "saber teeth" on Thylacosmilus had a triangle shaped cross-section and they slightly splayed out, these were not efficient killing weapons and were more like tusks than saber teeth. Also Thylacosmilus had no upper incisors, reduced lower incisors and small blunt molars, meaning it couldn't even eat a carcass once if it somehow managed to kill something. There are also lots of other little differences such as no bony symphysis connecting the two halves of the lower jaw, further weakening it and a small infraorbital opening, meaning this animal lacked the fine whiskers most predators have to sense their environment. Even Smilodon relied on its whiskers to pinpoint the exact spot to bite and drive in its famous sabers. If Thylacosmilus wasn't a carnivore, what was it? No one knows entirely for sure but the most likely to be correct hypothesis was it was an insectivore feeding on eusocial insects because it has missing incisors like Sloth Bears and reduced molars like Aardwolves. Other wild theories range from it being a "guts specialist" feeding on only the organs and soft tissues of its prey, to it being a venomous "vampire" that would inject its prey with venom that would liquify its preys innards for a liquid diet to a worm specialist that specialized in feeding on giant species of earthworm like Rhinodriles which can grow to the size of snakes. It is also entirely possible that Thylacosmilus could have filled an entirely unique niche unlike anything alive today, we really can't say until we have more evidence. Like I said my money is on an insectivorous niche.
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  6. Dinocerata next...
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  7. you mean EAST every time you say West
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  8. Amazing what galactic bioengineering corporations can come up with in their laboratories over the eons. After the fifth planet was destroyed and Mars atmosphere stripped during a war, the damage done to Earth required repopulating it with more species. You will never see “evolution” in action as life does not work that way.
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