We now call them non avian dinosaurs and avian dinosaurs.

Birds are living dinosaurs.

Avian dinosaurs are our modern birds.

But birds are dinosaurs.

You can call it a dinosaur, but look at the velociraptor the velociraptor is cool.

And sure enough, Nanotyrannus has juvenile bone and the bigger one has more mature bone.

We actually classify them as dinosaurs.

So here was the character that linked birds and dinosaurs.

There's the skull, pretty much the same shape as the Camarasaurus.

The bone histology tells us that Edmontosaurus is a juvenile, or at least a sub adult, and the other one is an adult and we have an ontogeny.

It looks rather bird like because it is.

It's bird like and hollow.

And if you cut into an older dinosaur, it's very massive.

And Torosaurus, when we cut into it, has mature bone.

So if we cut open Dracorex I cut open our Dracorex and look, it was spongy inside, really spongy inside.

228 million years old, we found what really is the most primitive dinosaur that's the Ur dinosaur.

Now as you can imagine, cutting open a leg bone is one thing, but when you go to a museum and say, You don't mind if I cut open your dinosaur's skull do you?

No dice no dodo skeleton for me. But the damage had been done.

If you cut open Stygimoloch, it is doing the same thing.

And so she looked into the bone of this T. rex, one of the thigh bones, and she actually found some very interesting structures in there.

So the non avian dinosaurs are the big clunky ones that went extinct.

And I have been fortunate enough to find things like the first eggs in the Western hemisphere and the first baby dinosaurs in nests, the first dinosaur embryos and massive accumulations of bones.

And the little one is really spongy.

See, while museums all over the world have dodo skeletons in their collection, nobody not even the actual Natural History Museum on the island of Mauritius has a skeleton that's made from the bones of a single dodo.

This guy I love this guy! He put a dodo leg bones on a scanner with a ruler.

There's a kind of truncated Camarasaurus skeleton, but the geometry's correct.

And I thought to myself, wouldn't it be great if I had my own dodo skeleton?

Fossilized remnants of skin still cover the bumpy armor plates dotting the animal's skull.

This is one of my papers A pygostyle from a non avian theropod.

Now, luckily, this Thrinaxodon, the size of a robin egg here this is a skull I've discovered just before taking this picture there's a pen for scale it's really tiny this is in the Lower Triassic, after the mass extinction has finished.

But cutting into the bones of a dinosaur is hard to do, as you can imagine, because in museums bones are precious.

But what was interesting was the adult Triceratops was also spongy.

And I looked down at this Sculpey, and I thought, maybe, yeah, maybe I could make my own dodo skull.

And after about six weeks, I finished, painted, mounted my own dodo skeleton.

Sort of a timeline, very non linear scale, nature rates and trilobites and dinosaurs, and eventually we saw some humans with caves ... Birds were flying overhead, after pterosaurs.

Storm trooper costumes. Maps of Middle Earth that's one I hand drew myself. There's the dodo skeleton folder.

So if you cut open a little dinosaur, it's very spongy inside like A.

So enormous excavations and a lot of work, and out of essentially a partial herd of dinosaurs that you saw buried there 20 tons of material we erect Jobaria, a sauropod dinosaur like we haven't seen on some other continents.

The beak is a thin layer of horny sheath, which is hollow inside and only has some of the thin bone to support.

I wasn't thinking about a dodo skeleton I just noticed that as I finished this skull, the armature wire that I had been used to holding it up was sticking out of the back just where a spine would be.

A three and a half foot thing, beautiful skull, predator, meat eater, a two legged animal.

But I have a museum and I collect dinosaurs and I can saw mine open.

If you look along the edge of the frill, they have these little triangular bones that actually grow big as triangles and then they flatten against the frill pretty much like the spikes do on the Pachycephalosaurs.

Dracorex is the littlest one, Stygimoloch is the middle size one, Pachycephalosaurus is the largest one.

Birds fly. Birds and angels.