[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.98,0:00:04.77,Default,,0000,0000,0000,,Shall I ask for a show\Nof hands or a clapping
Dialogue: 0,0:00:06.14,0:00:08.24,Default,,0000,0000,0000,,of people in different generations?
Dialogue: 0,0:00:08.27,0:00:11.98,Default,,0000,0000,0000,,I'm interested in how many\Nare three to 12 years old.
Dialogue: 0,0:00:12.00,0:00:17.25,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:17.27,0:00:18.56,Default,,0000,0000,0000,,None, huh?
Dialogue: 0,0:00:18.58,0:00:19.96,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:19.98,0:00:21.19,Default,,0000,0000,0000,,All right.
Dialogue: 0,0:00:21.81,0:00:23.57,Default,,0000,0000,0000,,I'm going to talk about dinosaurs.
Dialogue: 0,0:00:23.59,0:00:25.98,Default,,0000,0000,0000,,Do you remember dinosaurs\Nwhen you were that age?
Dialogue: 0,0:00:26.00,0:00:31.47,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:00:33.60,0:00:35.98,Default,,0000,0000,0000,,Dinosaurs are kind of funny, you know.
Dialogue: 0,0:00:36.00,0:00:38.50,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:38.52,0:00:41.43,Default,,0000,0000,0000,,We're going to kind of go\Nin a different direction right now.
Dialogue: 0,0:00:41.45,0:00:42.98,Default,,0000,0000,0000,,I hope you all realize that.
Dialogue: 0,0:00:43.55,0:00:45.78,Default,,0000,0000,0000,,So I'll just give you my message up front:
Dialogue: 0,0:00:46.36,0:00:47.97,Default,,0000,0000,0000,,Try not to go extinct.
Dialogue: 0,0:00:47.99,0:00:49.33,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:49.36,0:00:50.54,Default,,0000,0000,0000,,That's it.
Dialogue: 0,0:00:50.57,0:00:54.98,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:55.92,0:00:57.12,Default,,0000,0000,0000,,People ask me a lot --
Dialogue: 0,0:00:58.01,0:01:00.67,Default,,0000,0000,0000,,in fact, one of the most asked\Nquestions I get
Dialogue: 0,0:01:00.69,0:01:03.98,Default,,0000,0000,0000,,is, why do children\Nlike dinosaurs so much?
Dialogue: 0,0:01:04.00,0:01:05.98,Default,,0000,0000,0000,,What's the fascination?
Dialogue: 0,0:01:06.48,0:01:08.98,Default,,0000,0000,0000,,And I usually just say,
Dialogue: 0,0:01:09.00,0:01:10.98,Default,,0000,0000,0000,,"Well, dinosaurs were big,
Dialogue: 0,0:01:11.83,0:01:13.98,Default,,0000,0000,0000,,different and gone."
Dialogue: 0,0:01:15.20,0:01:16.49,Default,,0000,0000,0000,,They're all gone.
Dialogue: 0,0:01:16.52,0:01:17.98,Default,,0000,0000,0000,,Well that's not true,
Dialogue: 0,0:01:18.59,0:01:20.72,Default,,0000,0000,0000,,but we'll get to the goose in a minute.
Dialogue: 0,0:01:20.75,0:01:23.24,Default,,0000,0000,0000,,So that's sort of the theme:
Dialogue: 0,0:01:23.27,0:01:25.90,Default,,0000,0000,0000,,big, different and gone.
Dialogue: 0,0:01:27.14,0:01:28.81,Default,,0000,0000,0000,,The title of my talk:
Dialogue: 0,0:01:28.83,0:01:30.88,Default,,0000,0000,0000,,Shape-shifting Dinosaurs:
Dialogue: 0,0:01:30.90,0:01:32.98,Default,,0000,0000,0000,,The cause of a premature extinction.
Dialogue: 0,0:01:34.00,0:01:36.79,Default,,0000,0000,0000,,Now I assume that we remember dinosaurs.
Dialogue: 0,0:01:36.82,0:01:39.72,Default,,0000,0000,0000,,And there's lots of different shapes.
Dialogue: 0,0:01:39.74,0:01:42.20,Default,,0000,0000,0000,,Lots of different kinds.
Dialogue: 0,0:01:42.22,0:01:43.98,Default,,0000,0000,0000,,A long time ago,
Dialogue: 0,0:01:44.69,0:01:49.84,Default,,0000,0000,0000,,back in the early 1900s,\Nmuseums were out looking for dinosaurs.
Dialogue: 0,0:01:49.86,0:01:51.98,Default,,0000,0000,0000,,They went out and gathered them up.
Dialogue: 0,0:01:52.60,0:01:54.37,Default,,0000,0000,0000,,And this is an interesting story.
Dialogue: 0,0:01:55.20,0:01:59.23,Default,,0000,0000,0000,,Every museum wanted a little bigger\Nor better one than anybody else had.
Dialogue: 0,0:01:59.26,0:02:06.05,Default,,0000,0000,0000,,So if the museum in Toronto went out\Nand collected a Tyrannosaur, a big one,
Dialogue: 0,0:02:06.07,0:02:10.01,Default,,0000,0000,0000,,then the museum in Ottawa\Nwanted a bigger one, and a better one.
Dialogue: 0,0:02:10.79,0:02:12.62,Default,,0000,0000,0000,,And that happened for all museums.
Dialogue: 0,0:02:12.64,0:02:16.70,Default,,0000,0000,0000,,So everyone was out looking\Nfor all these bigger and better dinosaurs.
Dialogue: 0,0:02:17.90,0:02:20.12,Default,,0000,0000,0000,,And this was in the early 1900s.
Dialogue: 0,0:02:21.15,0:02:23.98,Default,,0000,0000,0000,,By about 1970,
Dialogue: 0,0:02:24.86,0:02:29.16,Default,,0000,0000,0000,,some scientists were sitting around\Nand they thought, "What in the world --
Dialogue: 0,0:02:29.72,0:02:32.11,Default,,0000,0000,0000,,Look at these dinosaurs, they're all big.
Dialogue: 0,0:02:33.75,0:02:35.59,Default,,0000,0000,0000,,Where are all the little ones?"
Dialogue: 0,0:02:35.75,0:02:37.43,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:02:38.57,0:02:42.09,Default,,0000,0000,0000,,And they thought about it\Nand they even wrote papers about it:
Dialogue: 0,0:02:42.11,0:02:43.98,Default,,0000,0000,0000,,"Where are the little dinosaurs?"
Dialogue: 0,0:02:44.00,0:02:50.46,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:02:52.90,0:02:55.98,Default,,0000,0000,0000,,Well, go to a museum, you'll see,
Dialogue: 0,0:02:56.54,0:02:58.98,Default,,0000,0000,0000,,see how many baby dinosaurs there are.
Dialogue: 0,0:02:59.66,0:03:02.45,Default,,0000,0000,0000,,People assumed --\Nand this was actually a problem --
Dialogue: 0,0:03:02.47,0:03:06.78,Default,,0000,0000,0000,,people assumed\Nthat if they had little dinosaurs,
Dialogue: 0,0:03:06.80,0:03:10.50,Default,,0000,0000,0000,,if they had juvenile dinosaurs,\Nthey'd be easy to identify.
Dialogue: 0,0:03:10.53,0:03:14.40,Default,,0000,0000,0000,,You'd have a big dinosaur\Nand a littler dinosaur.
Dialogue: 0,0:03:14.42,0:03:15.72,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:03:15.87,0:03:17.98,Default,,0000,0000,0000,,But all they had were big dinosaurs.
Dialogue: 0,0:03:18.98,0:03:20.98,Default,,0000,0000,0000,,And it comes down to a couple of things.
Dialogue: 0,0:03:21.00,0:03:25.14,Default,,0000,0000,0000,,First off, scientists have egos,
Dialogue: 0,0:03:25.78,0:03:28.98,Default,,0000,0000,0000,,and scientists like to name dinosaurs.
Dialogue: 0,0:03:29.66,0:03:30.98,Default,,0000,0000,0000,,They like to name anything.
Dialogue: 0,0:03:31.00,0:03:34.96,Default,,0000,0000,0000,,Everybody likes to have\Ntheir own animal that they named.
Dialogue: 0,0:03:34.98,0:03:37.96,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:03:37.98,0:03:41.29,Default,,0000,0000,0000,,And so every time they found something\Nthat looked a little different,
Dialogue: 0,0:03:41.31,0:03:43.17,Default,,0000,0000,0000,,they named it something different.
Dialogue: 0,0:03:43.67,0:03:45.07,Default,,0000,0000,0000,,And what happened, of course,
Dialogue: 0,0:03:45.09,0:03:48.76,Default,,0000,0000,0000,,is we ended up with a whole\Nbunch of different dinosaurs.
Dialogue: 0,0:03:50.64,0:03:52.98,Default,,0000,0000,0000,,In 1975,
Dialogue: 0,0:03:54.30,0:03:56.50,Default,,0000,0000,0000,,a light went on in somebody's head.
Dialogue: 0,0:03:56.83,0:04:01.05,Default,,0000,0000,0000,,Dr. Peter Dodson\Nat the University of Pennsylvania
Dialogue: 0,0:04:01.08,0:04:07.84,Default,,0000,0000,0000,,actually realized that dinosaurs\Ngrew kind of like birds do,
Dialogue: 0,0:04:08.67,0:04:12.22,Default,,0000,0000,0000,,which is different\Nthan the way reptiles grow.
Dialogue: 0,0:04:12.25,0:04:13.83,Default,,0000,0000,0000,,And in fact,
Dialogue: 0,0:04:13.85,0:04:17.37,Default,,0000,0000,0000,,he used the cassowary as an example.
Dialogue: 0,0:04:17.39,0:04:20.44,Default,,0000,0000,0000,,And it's kind of cool --\Nif you look at the cassowary,
Dialogue: 0,0:04:20.46,0:04:23.69,Default,,0000,0000,0000,,or any of the birds\Nthat have crests on their heads,
Dialogue: 0,0:04:23.72,0:04:30.35,Default,,0000,0000,0000,,they grow to about 80 percent adult size\Nbefore the crest starts to grow.
Dialogue: 0,0:04:31.43,0:04:32.98,Default,,0000,0000,0000,,Now think about that.
Dialogue: 0,0:04:33.00,0:04:35.98,Default,,0000,0000,0000,,They're basically retaining\Ntheir juvenile characteristics
Dialogue: 0,0:04:36.00,0:04:39.52,Default,,0000,0000,0000,,very late in what we call ontogeny.
Dialogue: 0,0:04:39.54,0:04:45.47,Default,,0000,0000,0000,,So allometric cranial ontogeny\Nis relative skull growth.
Dialogue: 0,0:04:46.00,0:04:52.43,Default,,0000,0000,0000,,So you can see that if you actually found\None that was 80 percent grown
Dialogue: 0,0:04:53.46,0:04:56.89,Default,,0000,0000,0000,,and you didn't know that it was going\Nto grow up to a cassowary,
Dialogue: 0,0:04:56.91,0:04:59.43,Default,,0000,0000,0000,,you would think\Nthey were two different animals.
Dialogue: 0,0:05:00.17,0:05:02.98,Default,,0000,0000,0000,,So this was a problem,
Dialogue: 0,0:05:03.00,0:05:08.56,Default,,0000,0000,0000,,and Peter Dodson pointed this out\Nusing some duck-billed dinosaurs
Dialogue: 0,0:05:09.06,0:05:10.56,Default,,0000,0000,0000,,then called Hypacrosaurus.
Dialogue: 0,0:05:10.59,0:05:15.45,Default,,0000,0000,0000,,And he showed that if you were to take\Na baby and an adult
Dialogue: 0,0:05:15.48,0:05:18.78,Default,,0000,0000,0000,,and make an average\Nof what it should look like,
Dialogue: 0,0:05:18.80,0:05:21.54,Default,,0000,0000,0000,,if it grew in sort of a linear fashion,
Dialogue: 0,0:05:22.05,0:05:25.99,Default,,0000,0000,0000,,it would have a crest\Nabout half the size of the adult.
Dialogue: 0,0:05:26.24,0:05:32.06,Default,,0000,0000,0000,,But the actual subadult at 65 percent\Nhad no crest at all.
Dialogue: 0,0:05:32.32,0:05:33.98,Default,,0000,0000,0000,,So this was interesting.
Dialogue: 0,0:05:34.00,0:05:39.45,Default,,0000,0000,0000,,So this is where people went astray again.
Dialogue: 0,0:05:40.11,0:05:42.72,Default,,0000,0000,0000,,I mean, if they'd have just taken that,
Dialogue: 0,0:05:42.74,0:05:45.76,Default,,0000,0000,0000,,taken Peter Dodson's work,\Nand gone on with that,
Dialogue: 0,0:05:45.78,0:05:48.98,Default,,0000,0000,0000,,then we would have a lot less\Ndinosaurs than we have.
Dialogue: 0,0:05:49.66,0:05:53.43,Default,,0000,0000,0000,,But scientists have egos;\Nthey like to name things.
Dialogue: 0,0:05:54.12,0:05:59.14,Default,,0000,0000,0000,,And so they went on naming dinosaurs\Nbecause they were different.
Dialogue: 0,0:06:00.14,0:06:02.80,Default,,0000,0000,0000,,Now we have a way of actually testing
Dialogue: 0,0:06:02.82,0:06:07.74,Default,,0000,0000,0000,,to see whether a dinosaur, or any animal,\Nis a young one or an older one.
Dialogue: 0,0:06:08.14,0:06:11.39,Default,,0000,0000,0000,,And that's by actually\Ncutting into their bones.
Dialogue: 0,0:06:11.89,0:06:18.66,Default,,0000,0000,0000,,But cutting into the bones of a dinosaur\Nis hard to do, as you can imagine,
Dialogue: 0,0:06:18.69,0:06:23.73,Default,,0000,0000,0000,,because in museums, bones are precious.
Dialogue: 0,0:06:25.84,0:06:28.70,Default,,0000,0000,0000,,You go into a museum,\Nand they take really good care of them.
Dialogue: 0,0:06:28.72,0:06:31.79,Default,,0000,0000,0000,,They put them in foam, little containers.
Dialogue: 0,0:06:32.34,0:06:34.08,Default,,0000,0000,0000,,They're very well taken care of.
Dialogue: 0,0:06:36.17,0:06:40.09,Default,,0000,0000,0000,,They don't like it if you come in\Nand want to saw them open and look inside.
Dialogue: 0,0:06:40.11,0:06:41.11,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:06:41.14,0:06:44.54,Default,,0000,0000,0000,,So they don't normally let you do that.
Dialogue: 0,0:06:44.57,0:06:45.57,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:06:45.59,0:06:49.04,Default,,0000,0000,0000,,But I have a museum\Nand I collect dinosaurs
Dialogue: 0,0:06:50.13,0:06:51.99,Default,,0000,0000,0000,,and I can saw mine open.
Dialogue: 0,0:06:52.02,0:06:53.99,Default,,0000,0000,0000,,So that's what I do.
Dialogue: 0,0:06:54.02,0:06:58.69,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:07:00.70,0:07:03.36,Default,,0000,0000,0000,,So if you cut open a little dinosaur,
Dialogue: 0,0:07:03.39,0:07:06.08,Default,,0000,0000,0000,,it's very spongy inside, like A.
Dialogue: 0,0:07:06.10,0:07:08.98,Default,,0000,0000,0000,,And if you cut into an older dinosaur,\Nit's very massive.
Dialogue: 0,0:07:09.00,0:07:12.08,Default,,0000,0000,0000,,You can tell it's mature bone.
Dialogue: 0,0:07:12.10,0:07:14.14,Default,,0000,0000,0000,,So it's real easy to tell them apart.
Dialogue: 0,0:07:14.60,0:07:18.31,Default,,0000,0000,0000,,So what I want to do is show you these.
Dialogue: 0,0:07:18.33,0:07:22.23,Default,,0000,0000,0000,,In North America in the northern plains\Nof the United States
Dialogue: 0,0:07:22.26,0:07:25.98,Default,,0000,0000,0000,,and the southern plains\Nof Alberta and Saskatchewan,
Dialogue: 0,0:07:26.00,0:07:29.73,Default,,0000,0000,0000,,there's this unit of rock\Ncalled the Hell Creek Formation
Dialogue: 0,0:07:29.75,0:07:33.20,Default,,0000,0000,0000,,that produces the last\Ndinosaurs that lived on Earth.
Dialogue: 0,0:07:33.22,0:07:36.15,Default,,0000,0000,0000,,And there are 12 of them\Nthat everyone recognizes --
Dialogue: 0,0:07:36.17,0:07:39.98,Default,,0000,0000,0000,,I mean the 12 primary dinosaurs\Nthat went extinct.
Dialogue: 0,0:07:40.61,0:07:43.32,Default,,0000,0000,0000,,And so we will evaluate them.
Dialogue: 0,0:07:44.14,0:07:46.10,Default,,0000,0000,0000,,And that's sort of what I've been doing.
Dialogue: 0,0:07:46.12,0:07:51.25,Default,,0000,0000,0000,,So my students, my staff,\Nwe've been cutting them open.
Dialogue: 0,0:07:51.81,0:07:55.66,Default,,0000,0000,0000,,Now as you can imagine,\Ncutting open a leg bone is one thing,
Dialogue: 0,0:07:55.68,0:07:58.74,Default,,0000,0000,0000,,but when you go to a museum
Dialogue: 0,0:07:58.76,0:08:02.98,Default,,0000,0000,0000,,and say, "You don't mind if I cut open\Nyour dinosaur's skull, do you?"
Dialogue: 0,0:08:03.45,0:08:05.98,Default,,0000,0000,0000,,they say, "Go away."
Dialogue: 0,0:08:06.00,0:08:10.98,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:08:13.55,0:08:14.98,Default,,0000,0000,0000,,So here are 12 dinosaurs.
Dialogue: 0,0:08:15.00,0:08:18.22,Default,,0000,0000,0000,,And we want to look at these three first.
Dialogue: 0,0:08:18.74,0:08:22.12,Default,,0000,0000,0000,,So these are dinosaurs\Nthat are called Pachycephalosaurus.
Dialogue: 0,0:08:22.14,0:08:25.77,Default,,0000,0000,0000,,And everybody knows\Nthat these three animals are related.
Dialogue: 0,0:08:25.80,0:08:32.10,Default,,0000,0000,0000,,And the assumption is that they're related\Nlike cousins or whatever.
Dialogue: 0,0:08:32.12,0:08:37.96,Default,,0000,0000,0000,,But no one ever considered\Nthat they might be more closely related.
Dialogue: 0,0:08:37.98,0:08:39.21,Default,,0000,0000,0000,,In other words,
Dialogue: 0,0:08:39.23,0:08:41.98,Default,,0000,0000,0000,,people looked at them\Nand they saw the differences.
Dialogue: 0,0:08:42.58,0:08:45.98,Default,,0000,0000,0000,,And you all know\Nthat if you are going to determine
Dialogue: 0,0:08:46.00,0:08:48.91,Default,,0000,0000,0000,,whether you're related\Nto your brother or your sister,
Dialogue: 0,0:08:48.93,0:08:51.98,Default,,0000,0000,0000,,you can't do it by looking at differences.
Dialogue: 0,0:08:52.69,0:08:56.19,Default,,0000,0000,0000,,You can only determine relatedness\Nby looking for similarities.
Dialogue: 0,0:08:56.22,0:08:58.21,Default,,0000,0000,0000,,So people were looking at these
Dialogue: 0,0:08:58.24,0:09:00.67,Default,,0000,0000,0000,,and they were talking\Nabout how different they are.
Dialogue: 0,0:09:00.70,0:09:04.12,Default,,0000,0000,0000,,Pachycephalosaurus has a big,\Nthick dome on its head,
Dialogue: 0,0:09:04.14,0:09:06.84,Default,,0000,0000,0000,,and it's got some little bumps\Non the back of its head,
Dialogue: 0,0:09:06.86,0:09:09.98,Default,,0000,0000,0000,,and it's got a bunch of gnarly things\Non the end of its nose.
Dialogue: 0,0:09:10.79,0:09:16.55,Default,,0000,0000,0000,,And then Stygimoloch, another dinosaur\Nfrom the same age, lived at the same time,
Dialogue: 0,0:09:16.57,0:09:18.74,Default,,0000,0000,0000,,has spikes sticking out\Nthe back of its head.
Dialogue: 0,0:09:18.76,0:09:20.73,Default,,0000,0000,0000,,It's got a little, tiny dome,
Dialogue: 0,0:09:20.76,0:09:23.58,Default,,0000,0000,0000,,and it's got a bunch\Nof gnarly stuff on its nose.
Dialogue: 0,0:09:24.29,0:09:27.98,Default,,0000,0000,0000,,And then there's this thing\Ncalled Dracorex hogwartsia.
Dialogue: 0,0:09:29.23,0:09:30.66,Default,,0000,0000,0000,,Guess where that came from?
Dialogue: 0,0:09:30.68,0:09:31.84,Default,,0000,0000,0000,,Dragon.
Dialogue: 0,0:09:31.87,0:09:35.62,Default,,0000,0000,0000,,So here's a dinosaur that has spikes\Nsticking out of its head,
Dialogue: 0,0:09:35.64,0:09:38.98,Default,,0000,0000,0000,,no dome and gnarly stuff on its nose.
Dialogue: 0,0:09:39.48,0:09:42.23,Default,,0000,0000,0000,,Nobody noticed the gnarly stuff\Nsort of looked alike.
Dialogue: 0,0:09:43.10,0:09:44.70,Default,,0000,0000,0000,,But they did look at these three
Dialogue: 0,0:09:44.72,0:09:47.18,Default,,0000,0000,0000,,and they said, "These\Nare three different dinosaurs,
Dialogue: 0,0:09:47.20,0:09:50.12,Default,,0000,0000,0000,,and Dracorex is probably\Nthe most primitive of them.
Dialogue: 0,0:09:50.14,0:09:54.05,Default,,0000,0000,0000,,And the other one\Nis more primitive than the other."
Dialogue: 0,0:09:54.16,0:09:58.26,Default,,0000,0000,0000,,It's unclear to me how they actually\Nsorted these three of them out.
Dialogue: 0,0:09:58.28,0:10:00.17,Default,,0000,0000,0000,,But if you line them up,
Dialogue: 0,0:10:00.20,0:10:03.25,Default,,0000,0000,0000,,if you just take those three skulls\Nand just line them up,
Dialogue: 0,0:10:03.28,0:10:05.26,Default,,0000,0000,0000,,they line up like this.
Dialogue: 0,0:10:05.29,0:10:07.34,Default,,0000,0000,0000,,Dracorex is the littlest one,
Dialogue: 0,0:10:07.37,0:10:09.98,Default,,0000,0000,0000,,Stygimoloch is the middle-size one,
Dialogue: 0,0:10:10.00,0:10:11.98,Default,,0000,0000,0000,,Pachycephalosaurus is the largest one.
Dialogue: 0,0:10:12.00,0:10:15.98,Default,,0000,0000,0000,,And one would think,\Nthat should give me a clue.
Dialogue: 0,0:10:16.00,0:10:18.33,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:10:18.35,0:10:19.88,Default,,0000,0000,0000,,But it didn't give them a clue.
Dialogue: 0,0:10:19.91,0:10:21.08,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:10:21.10,0:10:24.18,Default,,0000,0000,0000,,Because, well we know why.
Dialogue: 0,0:10:24.20,0:10:27.34,Default,,0000,0000,0000,,Scientists like to name things.
Dialogue: 0,0:10:28.67,0:10:31.40,Default,,0000,0000,0000,,So if we cut open Dracorex --
Dialogue: 0,0:10:31.43,0:10:33.35,Default,,0000,0000,0000,,I cut open our Dracorex --
Dialogue: 0,0:10:33.38,0:10:37.60,Default,,0000,0000,0000,,and look, it was spongy inside,\Nreally spongy inside.
Dialogue: 0,0:10:37.62,0:10:41.32,Default,,0000,0000,0000,,I mean, it is a juvenile\Nand it's growing really fast.
Dialogue: 0,0:10:41.90,0:10:43.89,Default,,0000,0000,0000,,So it is going to get bigger.
Dialogue: 0,0:10:43.92,0:10:47.55,Default,,0000,0000,0000,,If you cut open Stygimoloch,\Nit is doing the same thing.
Dialogue: 0,0:10:47.58,0:10:51.21,Default,,0000,0000,0000,,The dome, that little dome,\Nis growing really fast.
Dialogue: 0,0:10:51.23,0:10:52.92,Default,,0000,0000,0000,,It's inflating very fast.
Dialogue: 0,0:10:53.56,0:10:56.94,Default,,0000,0000,0000,,What's interesting is the spike\Non the back of the Dracorex
Dialogue: 0,0:10:56.96,0:10:59.04,Default,,0000,0000,0000,,was growing very fast as well.
Dialogue: 0,0:10:59.07,0:11:02.32,Default,,0000,0000,0000,,The spikes on the back of the Stygimoloch\Nare actually resorbing,
Dialogue: 0,0:11:02.34,0:11:06.47,Default,,0000,0000,0000,,which means they're getting smaller\Nas that dome is getting bigger.
Dialogue: 0,0:11:06.50,0:11:08.98,Default,,0000,0000,0000,,And if we look at Pachycephalosaurus,
Dialogue: 0,0:11:09.00,0:11:12.25,Default,,0000,0000,0000,,Pachycephalosaurus has a solid dome
Dialogue: 0,0:11:12.28,0:11:17.24,Default,,0000,0000,0000,,and its little bumps on the back\Nof its head were also resorbing.
Dialogue: 0,0:11:17.27,0:11:20.98,Default,,0000,0000,0000,,So just with these three dinosaurs,
Dialogue: 0,0:11:21.00,0:11:23.70,Default,,0000,0000,0000,,as a scientist, we can easily hypothesize
Dialogue: 0,0:11:23.72,0:11:27.98,Default,,0000,0000,0000,,that it is just a growth series\Nof the same animal.
Dialogue: 0,0:11:29.20,0:11:31.69,Default,,0000,0000,0000,,Which of course means
Dialogue: 0,0:11:32.96,0:11:37.68,Default,,0000,0000,0000,,that Stygimoloch and Dracorex are extinct.
Dialogue: 0,0:11:37.70,0:11:42.67,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:11:42.69,0:11:44.03,Default,,0000,0000,0000,,OK.
Dialogue: 0,0:11:44.05,0:11:45.20,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:11:46.95,0:11:52.38,Default,,0000,0000,0000,,Which of course means\Nwe have 10 primary dinosaurs to deal with.
Dialogue: 0,0:11:53.23,0:11:58.17,Default,,0000,0000,0000,,So a colleague of mine at Berkeley --\Nhe and I were looking at Triceratops.
Dialogue: 0,0:11:58.20,0:12:00.51,Default,,0000,0000,0000,,And before the year 2000 --
Dialogue: 0,0:12:00.53,0:12:04.21,Default,,0000,0000,0000,,now remember, Triceratops was first\Nfound in the 1800s --
Dialogue: 0,0:12:04.23,0:12:09.40,Default,,0000,0000,0000,,before 2000, no one had ever seen\Na juvenile Triceratops.
Dialogue: 0,0:12:10.36,0:12:13.91,Default,,0000,0000,0000,,There's a Triceratops\Nin every museum in the world,
Dialogue: 0,0:12:13.93,0:12:16.98,Default,,0000,0000,0000,,but no one had ever collected a juvenile.
Dialogue: 0,0:12:18.42,0:12:19.82,Default,,0000,0000,0000,,And we know why, right?
Dialogue: 0,0:12:19.84,0:12:21.98,Default,,0000,0000,0000,,Because everybody wants to have a big one.
Dialogue: 0,0:12:22.84,0:12:24.88,Default,,0000,0000,0000,,So everyone had a big one.
Dialogue: 0,0:12:24.90,0:12:27.31,Default,,0000,0000,0000,,So we went out and collected\Na whole bunch of stuff
Dialogue: 0,0:12:27.33,0:12:29.34,Default,,0000,0000,0000,,and we found a whole bunch of little ones.
Dialogue: 0,0:12:29.36,0:12:31.98,Default,,0000,0000,0000,,They're everywhere,\Nthey're all over the place.
Dialogue: 0,0:12:32.58,0:12:34.85,Default,,0000,0000,0000,,So we have a whole bunch\Nof them at our museum.
Dialogue: 0,0:12:34.87,0:12:39.32,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:12:39.35,0:12:42.01,Default,,0000,0000,0000,,And everybody says\Nit's because I have a little museum.
Dialogue: 0,0:12:42.04,0:12:44.76,Default,,0000,0000,0000,,When you have a little museum,\Nyou have little dinosaurs.
Dialogue: 0,0:12:44.78,0:12:47.78,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:12:47.89,0:12:49.63,Default,,0000,0000,0000,,If you look at the Triceratops,
Dialogue: 0,0:12:49.66,0:12:51.89,Default,,0000,0000,0000,,you can see it's changing,\Nit's shape-shifting.
Dialogue: 0,0:12:52.32,0:12:55.85,Default,,0000,0000,0000,,As the juveniles are growing up,\Ntheir horns actually curve backwards.
Dialogue: 0,0:12:56.24,0:12:59.90,Default,,0000,0000,0000,,And then as they get older,\Nthe horns grow forward.
Dialogue: 0,0:12:59.92,0:13:01.30,Default,,0000,0000,0000,,And that's pretty cool.
Dialogue: 0,0:13:01.33,0:13:03.64,Default,,0000,0000,0000,,If you look along the edge of the frill,
Dialogue: 0,0:13:03.67,0:13:08.83,Default,,0000,0000,0000,,they have these little triangular bones\Nthat actually grow big as triangles
Dialogue: 0,0:13:08.86,0:13:11.56,Default,,0000,0000,0000,,and then they flatten against the frill
Dialogue: 0,0:13:11.58,0:13:15.16,Default,,0000,0000,0000,,pretty much like the spikes do\Non the Pachycephalosaurs.
Dialogue: 0,0:13:15.82,0:13:20.30,Default,,0000,0000,0000,,And then, because the juveniles\Nare in my collection,
Dialogue: 0,0:13:20.32,0:13:21.80,Default,,0000,0000,0000,,I cut them open ...
Dialogue: 0,0:13:21.83,0:13:22.98,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:13:23.00,0:13:24.18,Default,,0000,0000,0000,,and look inside.
Dialogue: 0,0:13:24.20,0:13:27.34,Default,,0000,0000,0000,,And the little one is really spongy.
Dialogue: 0,0:13:27.37,0:13:29.74,Default,,0000,0000,0000,,And the middle-size one is really spongy.
Dialogue: 0,0:13:29.77,0:13:34.64,Default,,0000,0000,0000,,But what was interesting\Nwas the adult Triceratops was also spongy.
Dialogue: 0,0:13:34.67,0:13:37.68,Default,,0000,0000,0000,,And this is a skull\Nthat is two meters long.
Dialogue: 0,0:13:38.11,0:13:39.98,Default,,0000,0000,0000,,It's a big skull.
Dialogue: 0,0:13:40.83,0:13:45.48,Default,,0000,0000,0000,,But there's another dinosaur\Nthat is found in this formation
Dialogue: 0,0:13:45.62,0:13:49.10,Default,,0000,0000,0000,,that looks like a Triceratops,\Nexcept it's bigger,
Dialogue: 0,0:13:49.13,0:13:51.09,Default,,0000,0000,0000,,and it's called Torosaurus.
Dialogue: 0,0:13:51.96,0:13:55.98,Default,,0000,0000,0000,,And Torosaurus, when we cut\Ninto it, has mature bone.
Dialogue: 0,0:13:56.44,0:13:58.48,Default,,0000,0000,0000,,But it's got these big\Nholes in its shield.
Dialogue: 0,0:13:58.50,0:13:59.66,Default,,0000,0000,0000,,And everybody says,
Dialogue: 0,0:13:59.68,0:14:03.34,Default,,0000,0000,0000,,"A Triceratops and a Torosaurus\Ncan't possibly be the same animal
Dialogue: 0,0:14:03.36,0:14:05.86,Default,,0000,0000,0000,,because one of them's bigger\Nthan the other one."
Dialogue: 0,0:14:05.88,0:14:10.52,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:14:10.54,0:14:13.01,Default,,0000,0000,0000,,"And it has holes in its frill."
Dialogue: 0,0:14:13.04,0:14:15.100,Default,,0000,0000,0000,,And I said, "Well do we have\Nany juvenile Torosauruses?"
Dialogue: 0,0:14:16.02,0:14:20.61,Default,,0000,0000,0000,,And they said, "Well, no,\Nbut it has holes in its frill."
Dialogue: 0,0:14:21.46,0:14:24.92,Default,,0000,0000,0000,,So one of my graduate\Nstudents, John Scannella,
Dialogue: 0,0:14:24.94,0:14:26.66,Default,,0000,0000,0000,,looked through our whole collection
Dialogue: 0,0:14:26.68,0:14:32.80,Default,,0000,0000,0000,,and he actually discovered that the hole\Nstarting to form in Triceratops
Dialogue: 0,0:14:32.82,0:14:35.96,Default,,0000,0000,0000,,and, of course it's open, in Torosaurus --
Dialogue: 0,0:14:35.98,0:14:41.12,Default,,0000,0000,0000,,so he found the transitional ones\Nbetween Triceratops and Torosaurus,
Dialogue: 0,0:14:41.14,0:14:42.38,Default,,0000,0000,0000,,which was pretty cool.
Dialogue: 0,0:14:42.40,0:14:48.53,Default,,0000,0000,0000,,So now we know that Torosaurus\Nis actually a grown-up Triceratops.
Dialogue: 0,0:14:49.96,0:14:51.74,Default,,0000,0000,0000,,Now when we name dinosaurs,
Dialogue: 0,0:14:51.77,0:14:55.30,Default,,0000,0000,0000,,when we name anything,\Nthe original name gets to stick
Dialogue: 0,0:14:55.33,0:14:59.17,Default,,0000,0000,0000,,and the second name is thrown out.
Dialogue: 0,0:14:59.94,0:15:02.13,Default,,0000,0000,0000,,So Torosaurus is extinct.
Dialogue: 0,0:15:03.44,0:15:07.26,Default,,0000,0000,0000,,Triceratops, if you've heard the news,\Na lot of the newscasters got it all wrong.
Dialogue: 0,0:15:07.28,0:15:10.83,Default,,0000,0000,0000,,They thought Torosaurus should be kept\Nand Triceratops thrown out,
Dialogue: 0,0:15:10.86,0:15:12.64,Default,,0000,0000,0000,,but that's not going to happen.
Dialogue: 0,0:15:12.66,0:15:18.16,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:15:18.18,0:15:21.46,Default,,0000,0000,0000,,All right, so we can do this\Nwith a bunch of dinosaurs.
Dialogue: 0,0:15:21.49,0:15:23.53,Default,,0000,0000,0000,,I mean, here's Edmontosaurus
Dialogue: 0,0:15:23.56,0:15:24.98,Default,,0000,0000,0000,,and Anatotitan.
Dialogue: 0,0:15:25.42,0:15:27.98,Default,,0000,0000,0000,,Anatotitan: giant duck.
Dialogue: 0,0:15:28.63,0:15:30.78,Default,,0000,0000,0000,,It's a giant duck-bill dinosaur.
Dialogue: 0,0:15:30.81,0:15:32.54,Default,,0000,0000,0000,,Here's another one.
Dialogue: 0,0:15:32.56,0:15:35.03,Default,,0000,0000,0000,,So we look at the bone histology.
Dialogue: 0,0:15:35.06,0:15:39.94,Default,,0000,0000,0000,,The bone histology tells us\Nthat Edmontosaurus is a juvenile,
Dialogue: 0,0:15:39.96,0:15:41.59,Default,,0000,0000,0000,,or at least a subadult,
Dialogue: 0,0:15:41.62,0:15:47.37,Default,,0000,0000,0000,,and the other one is an adult,\Nand we have an ontogeny.
Dialogue: 0,0:15:48.27,0:15:50.23,Default,,0000,0000,0000,,And we get rid of Anatotitan.
Dialogue: 0,0:15:51.40,0:15:53.22,Default,,0000,0000,0000,,So we can just keep doing this.
Dialogue: 0,0:15:53.24,0:15:56.58,Default,,0000,0000,0000,,And the last one is T. Rex.
Dialogue: 0,0:15:57.33,0:16:01.98,Default,,0000,0000,0000,,So there's these two dinosaurs,\NT. Rex and Nanotyrannus.
Dialogue: 0,0:16:02.00,0:16:04.89,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:16:04.91,0:16:07.63,Default,,0000,0000,0000,,Again, it makes you wonder.
Dialogue: 0,0:16:07.65,0:16:10.86,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:16:10.89,0:16:13.22,Default,,0000,0000,0000,,But they had a good question.
Dialogue: 0,0:16:13.25,0:16:16.13,Default,,0000,0000,0000,,They were looking at them and they said,\N"One's got 17 teeth,
Dialogue: 0,0:16:16.16,0:16:18.02,Default,,0000,0000,0000,,and the biggest one's got 12 teeth.
Dialogue: 0,0:16:18.04,0:16:19.91,Default,,0000,0000,0000,,And that doesn't make any sense at all,
Dialogue: 0,0:16:19.94,0:16:23.61,Default,,0000,0000,0000,,because we don't know of any dinosaurs\Nthat gain teeth as they get older.
Dialogue: 0,0:16:23.63,0:16:25.88,Default,,0000,0000,0000,,So it must be true --
Dialogue: 0,0:16:25.90,0:16:27.20,Default,,0000,0000,0000,,they must be different."
Dialogue: 0,0:16:28.64,0:16:29.98,Default,,0000,0000,0000,,So we cut into them.
Dialogue: 0,0:16:31.37,0:16:35.25,Default,,0000,0000,0000,,And sure enough,\NNanotyrannus has juvenile bone
Dialogue: 0,0:16:35.27,0:16:38.87,Default,,0000,0000,0000,,and the bigger one has more mature bone.
Dialogue: 0,0:16:39.44,0:16:41.84,Default,,0000,0000,0000,,It looks like it could still get bigger.
Dialogue: 0,0:16:41.87,0:16:44.09,Default,,0000,0000,0000,,And at the Museum\Nof the Rockies where we work,
Dialogue: 0,0:16:44.11,0:16:47.75,Default,,0000,0000,0000,,I have four T. rexes,\Nso I can cut a whole bunch of them.
Dialogue: 0,0:16:47.77,0:16:49.98,Default,,0000,0000,0000,,But I didn't have to cut\Nany of them really,
Dialogue: 0,0:16:50.00,0:16:52.98,Default,,0000,0000,0000,,because I just lined up their jaws
Dialogue: 0,0:16:53.00,0:16:56.31,Default,,0000,0000,0000,,and it turned out\Nthe biggest one had 12 teeth
Dialogue: 0,0:16:56.33,0:16:58.51,Default,,0000,0000,0000,,and the next smallest one had 13
Dialogue: 0,0:16:58.53,0:17:00.76,Default,,0000,0000,0000,,and the next smallest had 14.
Dialogue: 0,0:17:00.79,0:17:02.81,Default,,0000,0000,0000,,And of course, Nano has 17.
Dialogue: 0,0:17:02.83,0:17:05.72,Default,,0000,0000,0000,,And we just went out and looked\Nat other people's collections
Dialogue: 0,0:17:05.74,0:17:09.48,Default,,0000,0000,0000,,and we found one that has\Nsort of 15 teeth.
Dialogue: 0,0:17:09.50,0:17:12.28,Default,,0000,0000,0000,,So again, real easy to say
Dialogue: 0,0:17:12.31,0:17:16.98,Default,,0000,0000,0000,,that Tyrannosaurus ontogeny\Nincluded Nanotyrannus,
Dialogue: 0,0:17:17.69,0:17:22.32,Default,,0000,0000,0000,,and therefore we can take out\Nanother dinosaur.
Dialogue: 0,0:17:22.35,0:17:23.98,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:17:27.38,0:17:30.67,Default,,0000,0000,0000,,So when it comes down\Nto our end Cretaceous,
Dialogue: 0,0:17:30.69,0:17:32.24,Default,,0000,0000,0000,,we have seven left.
Dialogue: 0,0:17:34.10,0:17:35.38,Default,,0000,0000,0000,,And that's a good number.
Dialogue: 0,0:17:35.76,0:17:38.98,Default,,0000,0000,0000,,That's a good number\Nto go extinct, I think.
Dialogue: 0,0:17:39.60,0:17:40.84,Default,,0000,0000,0000,,Now as you can imagine,
Dialogue: 0,0:17:40.86,0:17:43.62,Default,,0000,0000,0000,,this is not very popular\Nwith fourth-graders.
Dialogue: 0,0:17:43.74,0:17:44.74,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:17:44.77,0:17:49.74,Default,,0000,0000,0000,,Fourth-graders love their dinosaurs,\Nthey memorize them.
Dialogue: 0,0:17:53.11,0:17:54.84,Default,,0000,0000,0000,,And they're not happy with this.
Dialogue: 0,0:17:54.87,0:17:57.48,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:17:57.51,0:17:58.70,Default,,0000,0000,0000,,Thank you very much.
Dialogue: 0,0:17:58.72,0:18:02.63,Default,,0000,0000,0000,,(Applause)