24 korrents from this recording
Every claim below is a statement made in this recording, quoted word for word and linked to the second it was said, so you can hear it rather than take our word for it. The wording comes from the transcript published alongside the recording; the sentence above each quote is our reading of the claim, not their wording.
0:17:29 · watch on youtube.com↗
Their wordsAnd yeah, big theropods, T-rex, is going to be a power walker. It's not going to run in the conventional biomechanical sense where both feet are off the ground at once.
0:20:52 · watch on youtube.com↗
Their wordsThese are weird and rare outcomes. These don't usually happen. The vast majority of active predation is on stuff much, much, much smaller than you.
0:23:56 · watch on youtube.com↗
Their wordsSo, giant eyeballs, they can either see very well, they can see a very long way in daylight, or they can see very well at night. And my suspicion is it's the latter. I think they're probably primarily nocturnal when they get that size.
0:29:32 · watch on youtube.com↗
Their wordsBut this is the absolute rule of thumb for how foraging and growth and predation operate across everything from fish to starfish, praying mantises, all the way up to things like big cats via stuff like crocodiles. It's how it works. So it'd be very weird if it didn't also operate for dinosaurs. And then, as I say, we've actually got the direct evidence for this from bite marks and stomach contents. They're taking small stuff.
0:35:00 · watch on youtube.com↗
Their wordsThey're relatively efficient compared to a lot of other things, and particularly compared to the herbivores, so that means they're probably looking at long distance rather than speed.
0:37:55 · watch on youtube.com↗
Our reading
The scavenger-versus-hunter argument about T. rex is over: the bite marks show it did both.
Their wordsThey're obviously both. A, because we've got things like the bite marks I just described, which is pretty much definitive scavenging, and then we've got the healed bite marks with T-rex teeth buried in bones, which is pretty much definitive active predation. So we've got evidence of it doing both.
1:07:45 · watch on youtube.com↗
Their wordsBut fossils are in places that erode, and if we don't dig them up, they're gone. So we should dig all the fossils up now, and then we've got forever to study them.
1:17:50 · watch on youtube.com↗
Their wordsYou're dominant in contests, particularly with conspecifics. If you're trying to win a territory or win mating rights, bigger things usually beat up smaller things. So there's going to be selection favoring them. But then big things don't usually do well in extinction events, so that tends to reset the clock by killing off the big stuff, and then smaller stuff does better again.
1:22:01 · watch on youtube.com↗
Our reading
T. rex was not an apex predator: an apex predator eats other predators, and T. rex ate herbivores.
Their wordsI have a problem with the term apex predator because ecologically, apex predators are generally defined as things that eat other predators. So a great white shark is, because it's eating stuff like tuna and sea lions, which are themselves predators, so it's a predator of predators. Whereas people love saying lions are apex predators, and they love saying T-Rex is an apex predator. They're eating herbivores.
1:23:22 · watch on youtube.com↗
Their wordsBut fundamentally, T-Rex is definitely weird, even compared to all the other giant tyrannosaurs that are very closely related to it, because it is by far, ludicrously by far, the largest carnivore in its ecosystem.
1:34:41 · watch on youtube.com↗
Their wordsSo, I think it's just straight fiction. It works for the book and it works for the movie, but it's... as far as I can tell, it's straight fiction, and Crichton just made it up. If it's buried in some bit of literature, he's done better finding it than I have, and I've had a really good look, and I know how to look.
1:35:21 · watch on youtube.com↗
Their wordsThe evidence for pack hunting in any dinosaur at all is almost nonexistent. It basically doesn't exist. And that's going exactly back to, again, that stuff we were talking about, bite marks and taphonomy and the history of specimens and how you interpret stuff.
1:46:23 · watch on youtube.com↗
Their wordsThere are various canids that all hunt in groups, but then you've got things like maned wolves, which are effectively solitary. The hyenas. Spotted hyenas are, yeah, these super social animals, but the brown hyena, the striped hyena, and the aardwolf are solitary. So you just can't do group versus solitary off close relatives or anything like that.
1:52:12 · watch on youtube.com↗
Their wordsSo the instant assumption is, okay, so you can tell female from male. No, we can tell laying female from everything else. So males won't have medullary bone. Young females won't have them. Females outside of the breeding season won't have it.
2:09:42 · watch on youtube.com↗
Their wordsAnd that's the thing, it's the pool of data, and I think that's what people miss. We as paleontologists get caught up on single superlative specimens and then try and treat them as a silver bullet almost.
2:17:13 · watch on youtube.com↗
Our reading
The papers claiming Spinosaurus was a diver or a strong swimmer rest on very weak evidence at best.
Their wordsSo Spinosaurus is a super weird and exaggerated version of what was already a kind of super weird group of theropods. So Spinosaurus is properly strange. And then, as you kind of hinted at, super controversial as well, because various papers have claimed it's a diver or a really good swimmer, and I think the evidence for that is very weak at best.
2:34:14 · watch on youtube.com↗
Their wordsBut I'm being obviously overly facetious, but if ultimately part of your scaling is how big is the animal versus how big is its brain, that's most of a T-Rex brain. It's a fraction of the size of a chimp brain, and chimps don't weigh seven tons.
2:45:01 · watch on youtube.com↗
Their wordsThere are five recognized mass extinctions in the history of life on Earth, and all of them are ultimately some form of climate change. Whether it's volcanic eruptions or hyper-oxygenation, or an ice age or whatever, it's climate changing too quickly for things to adapt to.
2:48:32 · watch on youtube.com↗
Their wordsYes, it's what ultimately killed the dinosaurs, but I'd be amazed if there wasn't some equivalent of Hawaii or New Zealand or some other tucked away island or valley where actually dinosaurs were fine for anything from a few hundred thousand to a couple of million years.
2:52:21 · watch on youtube.com↗
Their wordsBut yeah, there's been a back and forth about whether dinosaurs were already on their way out or were they a bit limited by the very end of the Cretaceous. I think the more recent analyses have shown that's probably not the case, because in other words, they were basically doing fine right up to the extinction event. And so yeah, if the asteroid hadn't hit, there's no reason to think that they were on some kind of terminal decline.
3:03:46 · watch on youtube.com↗
Their wordsWhy don't Chinese dragons look like Mexican dragons or equivalent thunderbirds or whatever? Well, because it probably wasn't influencing them. If they were all seeing the same skeleton, they'd probably all produce the same kind of mythical animals.
3:12:02 · watch on youtube.com↗
Their wordsI think people think evolution is, like, perfecting things in some way. And they're not. They're bodge jobs, you know? That's why we have a blind spot in our eye, but things like squid don't.
3:18:56 · watch on youtube.com↗
Their wordsSo birds did not appear as a result of the dinosaurs going extinct. Birds lived alongside the dinosaurs for 100 million years. The birds were not new on the scene, and it's not like, "Oh, the dinosaurs died, and from the ashes rose the birds." No, they've been knocking around forever.
3:34:45 · watch on youtube.com↗
Their wordsBecause actually, however cool these new things are, genuinely if you want to know what dinosaurs are and how they worked, another hundred Protoceratops will actually probably tell us a lot more than 50 new species, however cool 50 new species might be.