Dave Hone

There might be 200 elephants.

So who's likely to have more genes or who's likely to have selection acting on those genes to produce a survivor, uh,

Well, the one with five or ten or a thousand times the population.

And then, yeah, on top of that, you've then got the very slow reproductive cycle, which then, again, gives evolution not a lot to work with.

If as an elephant you're breeding once every five years and as a mouse you're doing it once every eight weeks.

So that starts kicking in seriously, kind of euteranocysin up.

So that's when you start getting, they're not just bigger animals that are getting to a comparable size to the other big dinosaur carnivores of the time, you start getting those bigger heads.

Yeah.

But even then, relatively late in Tyrannosaur evolution, so getting into kind of the middle part of the late Cretaceous, you see a split.

And we have a group called the Eleoramines, which have really, really long, thin skulls.

And they look much more like a kind of, as a Velociraptor, they look much more like a giant Velociraptor

ish than a tyrannosaur still relatively small arms but it's a very long snout and so this is a fast biting animal with a relatively light bite so it's probably taking really quite small stuff proportionally and then the other side you've got the tyrannosaur eins which are the really big headed ones and so that is

A few ancestral things like Albertosaurus and Gorgosaurus, both from Alberta.

But then Dasplidosaurus, a thing I named called Jucheng Tyrannus in China, and then Tarbosaurus and Tyrannosaurus.

And you've really only got three or four of these ultra giants, which are all kind of 10 meters plus in size, and then have the really broad skull with the real kind of excessive bite force.

But even things like Albertosaurus,

which is a big animal, seven, eight meters, a ton or so.

They're not quite T-Rex, but they're definitely more robust than the other contemporaneous carnivores.

So there is this progression of getting bigger, getting a bigger head, the teeth get bigger, but there's fewer of them, building up the bone biting and the power.

But with some interesting evolutionary off-branches in the way that, yeah, cats are largely much of a muchness, but then you get things like bobcats and lynx, which are actually quite bulky, stocky little cats that don't have the long tail and are doing something quite different.