TEDxVancouver
Jack Horner: Where are the baby dinosaurs?
Jack Horner: Dinosaures que canvien de forma
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On són els cadells de dinosaure? En una xerrada fascinant des de TEDxVancouver, el paleontòleg Jack Horner ens descriu com la realització de làmines en cranis fòssils va revel.lar un secret impactant sobre alguns dels nostres dinosaures més estimats.
Jack Horner - Dinosaur digger
Jack Horner and his dig teams have discovered the first evidence of parental care in dinosaurs, extensive nesting grounds, evidence of dinosaur herds, and the world’s first dinosaur embryos. He's now exploring how to build a dinosaur. Full bio
Jack Horner and his dig teams have discovered the first evidence of parental care in dinosaurs, extensive nesting grounds, evidence of dinosaur herds, and the world’s first dinosaur embryos. He's now exploring how to build a dinosaur. Full bio
Double-click the English transcript below to play the video.
00:15
Shall I ask for a show of hands
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Puc demanar que aixequi la mà
00:18
or a clapping
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o que aplaudeixi
00:20
of people in different generations?
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la gent de generacions diferents?
00:23
I'm interested in how many
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Estic interessat en quants n’hi ha
00:25
are three to 12 years old.
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entre 3 i 12 anys.
00:27
(Laughter)
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(Riure)
00:31
None, huh?
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Ningú, oi?
00:34
All right.
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Molt bé.
00:36
I'm going to talk about dinosaurs.
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Parlaré de dinosaures.
00:38
Do you remember dinosaurs when you were that age?
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Us en recordeu dels dinosaures quan ereu petits?
00:41
(Applause)
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(Aplaudiments)
00:48
Dinosaurs are kind of funny, you know.
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Els dinosaures són divertits, ja sabeu.
00:51
(Laughter)
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(Riure)
00:53
We're going to kind of go in a different direction right now.
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Tot i que avui anirem en una altra direcció.
00:55
I hope you all realize that.
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Espero que us n'adoneu.
00:58
So I'll just give you my message up front:
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Per tant, us donaré el meu missatge sense embuts:
01:00
Try not to go extinct.
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Intenteu no extingir-vos.
01:02
(Laughter)
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(Riure)
01:04
That's it.
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Ja està.
01:06
(Laughter)
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(Riure)
01:10
People ask me a lot --
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La gent em demana sovint
01:12
in fact, one of the most asked questions I get
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(de fet, és una de les preguntes que més sovint em fan)
01:15
is, why do children like dinosaurs so much?
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perquè als nens els agraden tant els dinosaures?
01:19
What's the fascination?
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Què els fascina tant?
01:21
And I usually just say,
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I normalment jo simplement dic,
01:24
"Well dinosaurs were big,
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“Bé, els dinosaures eren grans,
01:26
different and gone."
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diferents, i ja no hi són.”
01:29
They're all gone.
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No en queda cap.
01:31
Well that's not true,
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Bé, això no és veritat,
01:33
but we'll get to the goose in a minute.
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però ja en parlarem a fons d’aquí a un minut
01:35
So that's sort of the theme:
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Bé, doncs aquest és si fa no fa el tema:
01:38
big, different and gone.
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grans, diferents i ja no hi són.
01:42
The title of my talk:
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El títol de la meva xerrada:
01:44
Shape-shifting Dinosaurs:
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Dinosaures que canvien de forma:
01:46
The Cause of a Premature Extinction.
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La Causa d’una Extinció Prematura
01:48
Now I assume that we remember dinosaurs.
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Suposo que tots recordem els dinosaures.
01:51
And there's lots of different shapes.
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I n’hi ha de diferents formes.
01:54
Lots of different kinds.
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De diferents tipus.
01:57
A long time ago,
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Fa molt de temps,
01:59
back in the early 1900s,
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al principi del segle XX,
02:01
museums were out looking for dinosaurs.
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els museus anaven buscant dinosaures.
02:04
They went out and gathered them up.
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Anaven a fora a recollir-los.
02:07
And this is an interesting story.
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I aquesta és una història interessant.
02:09
Every museum wanted a little bigger or better one
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Cada museu en volia un una mica més gran o millor
02:12
than anybody else had.
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del que qualsevol altre en tenia.
02:14
So if the museum in Toronto went out
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Per tant, si el museu de Toronto sortia
02:17
and collected a Tyrannosaur, a big one,
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i recollia un Tiranosaure, un de ben gran,
02:20
then the museum in Ottawa wanted a bigger one
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llavors el museu d’Ottawa en volia un de més gran
02:23
and a better one.
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i un de millor.
02:25
And that happened for all museums.
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I això passava amb tots els museus.
02:27
So everyone was out looking
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Al final tothom anava buscant
02:29
for all these bigger and better dinosaurs.
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els dinosaures més grans i millors.
02:32
And this was in the early 1900s.
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Això passava a principis del segle XX.
02:36
By about 1970,
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Cap als volts de 1970,
02:39
some scientists were sitting around
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alguns científics es van reunir
02:41
and they thought, "What in the world?
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i van pensar, “Què diantre?
02:44
Look at these dinosaurs.
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Mireu aquests dinosaures.
02:46
They're all big.
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Són tots grans.
02:48
Where are all the little ones?"
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On són els petits?”
02:53
And they thought about it
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I van rumiar-hi
02:55
and they even wrote papers about it:
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i fins i tot van escriure articles sobre el tema:
02:57
"Where are the little dinosaurs?"
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“On són els dinosaures petits?”
02:59
(Laughter)
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(Riure)
03:07
Well, go to a museum, you'll see,
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Bé, aneu a un museu i ja veureu,
03:11
see how many baby dinosaurs there are.
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fixeu-vos en quants cadells de dinosaure hi ha.
03:14
People assumed -- and this was actually a problem --
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La gent suposava (i això era de fet un problema)
03:17
people assumed
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La gent suposava
03:19
that if they had little dinosaurs,
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que si tinguéssin dinosaures petits,
03:21
if they had juvenile dinosaurs,
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si tinguéssin dinosaures joves,
03:23
they'd be easy to identify.
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serien fàcils d’identificar.
03:25
You'd have a big dinosaur
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Tindries un dinosaure gran
03:27
and a littler dinosaur.
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i un de més petitó.
03:30
But all they had were big dinosaurs.
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Però tot el que tenien eren dinosaures grans.
03:33
And it comes down to a couple of things.
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I això es deu a un parell de raons.
03:36
First off, scientists have egos,
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En primer lloc, els científics tenen egos,
03:40
and scientists like to name dinosaurs.
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i als científics els agrada posar noms als dinosaures.
03:44
They like to name anything.
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Els agrada posar noms a qualsevol cosa.
03:46
Everybody likes to have their own animal that they named.
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A tothom li agrada posar el seu nom a un animal.
03:49
(Laughter)
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(Riure)
03:52
And so every time they found something that looked a little different,
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I així, cada vegada que trobaven alguna cosa que semblava un xic diferent,
03:55
they named it something different.
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Li posaven un nom diferent.
03:58
And what happened, of course,
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I el que va passar, és clar,
04:00
is we ended up with a whole bunch of different dinosaurs.
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és que vam acabar amb una bona colla de dinosaures diferents.
04:05
In 1975,
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El 1975,
04:08
a light went on in somebody's head.
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a algú se li va encendre la bombeta dins del cap.
04:11
Dr. Peter Dodson
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Dr. Peter Dodson
04:13
at the University of Pennsylvania
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de la Universitat de Pennsylvania
04:15
actually realized
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es va adonar, de fet,
04:18
that dinosaurs grew
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que els dinosaures creixien
04:21
kind of like birds do,
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de la mateixa manera que els ocells,
04:23
which is different
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que és diferent
04:25
than the way reptiles grow.
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de la manera com creixen els rèptils.
04:27
And in fact,
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I de fet,
04:29
he used the cassowary as an example.
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va utilitzar el casuari com exemple.
04:32
And it's kind of cool -- if you look at the cassowary,
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I té la seva gràcia -- si mirem el casuari,
04:35
or any of the birds that have crests on their heads,
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o qualsevol dels ocells que tenen una cresta al cap,
04:38
they actually grow
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de fet, creixen
04:40
to about 80 percent adult size
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fins al 80 per cent del tamany adult
04:42
before the crest starts to grow.
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abans que la cresta comenci a créixer.
04:45
Now think about that.
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Penseu-hi atentament.
04:48
They're basically retaining their juvenile characteristics
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Bàsicament estàn retenint les seves característiques juvenils
04:51
very late in what we call ontogeny.
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fins a la maduresa. S’anomena ontogènia.
04:54
So allometric cranial ontogeny
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Així, la ontogènia cranial alomètrica
04:58
is relative skull growth.
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bàsicament és el creixement relatiu del crani.
05:01
So you can see
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Doncs ja veieu
05:03
that if you actually found one
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que si en trobàveu un
05:05
that was 80 percent grown
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que havia crescut un 80 per cent
05:08
and you didn't know that it was going to grow up to a cassowary,
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i que no sabíeu que arribaria a esdevenir un casuari,
05:11
you would think they were two different animals.
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pensarieu que eren dos animals diferents.
05:15
So this was a problem,
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Això era un problema,
05:18
and Peter Dodson pointed this out
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i en Peter Dodson s’en va adonar
05:21
using some duck-billed dinosaurs
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fent servir alguns dinosaures amb bec d’ànec
05:23
then called Hypacrosaurus.
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llavors anomenats Hipacrosaures.
05:25
And he showed
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i va mostrar
05:27
that if you were to take a baby and an adult
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que si agafàvem un cadell i un adult
05:30
and make an average of what it should look like,
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i feiem un promig del que hauria d’assemblar-se,
05:33
if it grew in sort of a linear fashion,
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si creixés d’aquesta forma lineal,
05:36
it would have a crest
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hauria de tenir una cresta
05:38
about half the size of the adult.
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de la meitat del tamany que la d’un adult.
05:41
But the actual sub-adult
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Però, de fet, el sub-adult
05:43
at 65 percent
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al 65 per cent
05:45
had no crest at all.
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no tenia cap cresta.
05:47
So this was interesting.
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I això era interessant.
05:49
So this is where
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I aquí és on la gent
05:52
people went astray again.
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va tornar a anar pel mal camí.
05:55
I mean, if they'd have just taken that,
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Vull dir que si tan sols haguéssin agafat això,
05:57
taken Peter Dodson's work, and gone on with that,
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el treball de Peter Dodson, i hi haguéssin continuat,
06:00
then we would have a lot less dinosaurs
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ara tindriem molts menys dinosaures
06:02
than we have.
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dels que tenim.
06:04
But scientists have egos;
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Però els científics tenen egos;
06:06
they like to name things.
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els agrada anomenar coses.
06:09
And so they went on naming dinosaurs
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I per tant van continuar anomenant dinosaures
06:12
because they were different.
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perquè eren diferents.
06:15
Now we have a way of actually testing
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Ara tenim una manera d’analitzar amb fiabilitat
06:17
to see whether a dinosaur, or any animal,
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si un dinosaure, o qualsevol altre animal,
06:20
is a young one or an older one.
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és un individu jove o vell.
06:23
And that's by actually cutting into their bones.
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Es fa bàsicament tallant-ne els ossos.
06:26
But cutting into the bones of a dinosaur
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Però tallar els ossos d’un dinosaure
06:30
is hard to do, as you can imagine,
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és difícil de fer, com ja podeu imaginar,
06:33
because in museums
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perquè els ossos
06:36
bones are precious.
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dels museus són preciosos.
06:40
You go into a museum and they take really good care of them.
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Si aneu a un museu veureu que en tenen molta cura.
06:43
They put them in foam, little containers.
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Els posen en petits contenidors folrats amb escuma.
06:46
They're very well taken care of.
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Són tractats amb molta cura.
06:50
They don't like it if you come in
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No els agrada que tu vinguis
06:52
and want to saw them open and look inside.
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i que vulguis serrar-los i mirar-hi a dins.
06:54
(Laughter)
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(Riure)
06:56
So they don't normally let you do that.
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Per tant normalment no et deixen fer això.
06:59
But I have a museum
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Però jo tinc un museu
07:02
and I collect dinosaurs
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I recullo dinosaures
07:04
and I can saw mine open.
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i puc serrar els meus.
07:06
So that's what I do.
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Per tant, és el que faig.
07:08
(Applause)
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(Aplaudiments)
07:13
So if you cut open a little dinosaur,
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Així, si talleu un dinosaure petit,
07:18
it's very spongy inside like A.
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és força esponjós per dins, com A.
07:20
And if you cut into an older dinosaur,
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I si talleu un dinosaure més vell,
07:22
it's very massive.
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és molt massiu.
07:24
You can tell it's mature bone.
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Es pot dir que és un os madur.
07:26
So it's real easy to tell them apart.
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I així és fàcil distingir-los.
07:29
So what I want to do
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Per tant el que jo vull fer
07:31
is show you these.
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és ensenyar-vos aquests.
07:33
In North America in the Northern Plains of the United States
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A l'Amèrica del Nord, a les planes septentrionals dels Estats Units
07:37
and the Southern Plains of Alberta and Saskatchewan,
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i a les planes meridionals d’Alberta i Saskatchewan, a Canadà,
07:41
there's this unit of rock called the Hell Creek Formation
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hi ha una unitat de roca anomenada Formació Hell Creek
07:44
that produces the last dinosaurs that lived on Earth.
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que proporciona els darrers dinosaures que van viure a la terra.
07:47
And there are 12 of them
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I n’hi ha 12 entre ells
07:49
that everyone recognizes --
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que tothom reconeix --
07:51
I mean the 12 primary dinosaurs
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vull dir els 12 dinosaures principals
07:53
that went extinct.
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que es van extingir.
07:55
And so we will evaluate them.
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Ara els avaluarem.
07:58
And that's sort of what I've been doing.
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Això és més o menys el que he estat fent.
08:00
So my students, my staff,
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Doncs amb els meus estudiants, el meu equip,
08:03
we've been cutting them open.
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hem estat obrint-los.
08:06
Now as you can imagine,
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Com us podeu imaginar,
08:08
cutting open a leg bone is one thing,
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obrir un os d’una cama és una cosa,
08:10
but when you go to a museum
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però quan un va a un museu
08:13
and say, "You don't mind if I cut open
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i diu, “Us fa res si obro
08:15
your dinosaur's skull do you?"
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el crani del vostre dinosaure?”
08:18
they say, "Go away."
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ells responen, “Fora d’aquí!”
08:21
(Laughter)
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(Riure)
08:26
So here are 12 dinosaurs.
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Bé, doncs aquí tenim 12 dinosaures.
08:30
And we want to look at these three first.
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Fixem-nos primer en aquests tres.
08:33
So these are dinosaurs that are called Pachycephalosaurs.
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Aquests son dinosaures anomenats Paquicefalosaures.
08:36
And everybody knows
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I tothom sap que
08:38
that these three animals are related.
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aquests tres animals estan emparentats.
08:40
And the assumption is
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Suposarem que
08:42
is that they're related
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estan emparentats
08:44
like cousins or whatever.
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com cosins o el que sigui.
08:47
But no one ever considered
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Però ningú no va considerar mai que
08:49
that they might be more closely related.
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poguéssin estar més íntimament emparentats.
08:52
In other words,
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En altres paraules,
08:54
people looked at them and they saw the differences.
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La gent s’els mirava i hi veia les diferències.
08:57
And you all know
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I tots vosaltres sabeu
08:59
that if you are going to determine
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que si heu de determinar
09:01
whether you're related to your brother or your sister,
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si esteu emparentats amb el vostre germà o germana,
09:03
you can't do it by looking at differences.
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no ho podeu fer mirant les diferències.
09:07
You can only determine relatedness
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Només es pot determinar el parentesc
09:09
by looking for similarities.
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buscant les similituds.
09:11
So people were looking at these
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Però la gent es mirava aquests
09:13
and they were talking about how different they are.
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i parlàven sobre com n’éren, de diferents.
09:15
Pachycephalosaurus has a big, thick dome on its head,
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El Paquicefalosaure té una protuberància gran i gruixuda al cap,
09:18
and it's got some little bumps on the back of its head,
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i té alguns petits bonys a la part del darrera del cap,
09:21
and it's got a bunch of gnarly things on the end of its nose.
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i té una colla de nòduls al final del nas.
09:25
And then Stygimoloch, another dinosaur
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I després el Stygimoloch, un altre dinosaure
09:27
from the same age, lived at the same time,
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de la mateixa època, que va viure al mateix temps,
09:31
has spikes sticking out the back of its head.
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té punxes que li surten del darrera del cap.
09:33
It's got a little, tiny dome,
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Té una diminuta protuberància,
09:35
and it's got a bunch of gnarly stuff on its nose.
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i té una colla de nòduls al nas.
09:39
And then there's this thing called Dracorex,
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I per últim tenim aquesta cosa anomenada Dracorex,
09:41
Hogwart's Eye.
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El favorit de Hogwarts.
09:43
Guess where that came from? Dragon.
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Sabeu d’on li ve el nom? Drac.
09:46
So here's a dinosaur
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Llavors, aquí hi ha un dinosaure
09:48
that has spikes sticking out of its head, no dome
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que té punxes que li surten del cap, sense protuberància
09:51
and gnarly stuff on its nose.
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i nòduls al nas.
09:54
Nobody noticed the gnarly stuff sort of looked alike.
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Ningú s’hi va fixar que els nòduls s’assemblaven.
09:57
But they did look at these three
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Però van mirar-se aquests tres
09:59
and they said, "These are three different dinosaurs,
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i van dir, “Aquests són tres dinosaures diferents,
10:01
and Dracorex is probably the most primitive of them.
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i el Dracorex és probablement el més primitiu d’ells.
10:04
And the other one is more primitive than the other.
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I aquest és més primitiu que l’altre.
10:07
It's unclear to me
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No acabo de tenir clar
10:10
how they actually sorted these three of them out.
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com els van ordenar, aquests tres.
10:13
But if you line them up,
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Però si els comparem,
10:15
if you just take those three skulls and just line them up,
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si prenem aquests tres cranis i els posem l'un al costat de l’altre,
10:18
they line up like this.
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s'ordenen així.
10:20
Dracorex is the littlest one,
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Dracorex és el més petitó
10:22
Stygimoloch is the middle size one,
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Stygimoloch és el mitjà,
10:24
Pachycephalosaurus is the largest one.
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i el Paquicefalosaure és el més gran.
10:27
And one would think,
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I un podria pensar,
10:29
that should give me a clue.
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això m’hauria de donar una pista.
10:31
(Laughter)
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(Riure)
10:33
But it didn't give them a clue.
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Però no s’en van adonar.
10:36
Because, well we know why.
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Donat que... bé, ja ho sabem.
10:39
Scientists like to name things.
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Als científics els agrada posar noms a les coses.
10:42
So if we cut open
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Per tant, si obrim
10:44
Dracorex --
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el Dracorex
10:46
I cut open our Dracorex --
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(jo vaig obrir el nostre Dracorex)
10:48
and look, it was spongy inside,
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i hi mirem, per dins era molt esponjós,
10:50
really spongy inside.
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realment molt esponjós per dins.
10:52
I mean, it is a juvenile
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Això vol dir que és jove
10:54
and it's growing really fast.
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i que està creixent molt ràpid.
10:56
So it is going to get bigger.
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I així es farà més gran.
10:58
If you cut open Stygimoloch,
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Si obrim un Stygimoloch,
11:00
it is doing the same thing.
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està fent el mateix.
11:02
The dome, that little dome,
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La protuberància, aquesta petita.
11:04
is growing really fast.
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està creixent realment ràpid.
11:06
It's inflating very fast.
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S’està inflant molt ràpid
11:08
What's interesting is the spike on the back of the Dracorex
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El que és interessant és que la punxa del darrera del Dracorex
11:11
was growing very fast as well.
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també estava creixent ràpidament.
11:13
The spikes on the back of the Stygimoloch
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Les punxes del darrera del Stygimoloch
11:15
are actually resorbing,
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estan de fet sent reabsorbides,
11:17
which means they're getting smaller
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que vol dir que es fan més petites
11:19
as that dome is getting bigger.
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mentre la protuberància es fa gran.
11:21
And if we look at Pachycephalosaurus,
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I si mirem el Paquicefalosaure,
11:24
Pachycephalosaurus has a solid dome
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El Paquicefalosaure té una protuberància massissa
11:27
and its little bumps on the back of its head
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i els petits bonys al darrera del seu cap
11:30
were also resorbing.
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estan també sent reabsorbits.
11:32
So just with these three dinosaurs,
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Així, amb només aquests tres dinosaures,
11:34
you can easily -- as a scientist --
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un pot fàcilment (com a científic)
11:36
we can easily hypothesize
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podem fer una hipòtesi fàcilment
11:38
that it is just a growth series
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que es tracta sols d’una sèrie de creixement
11:40
of the same animal.
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del mateix animal.
11:43
Which of course means
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Que vol dir, per suposat,
11:46
that Stygimoloch and Dracorex
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que el Stygimoloch i el Dracorex
11:50
are extinct.
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s’han extingit.
11:52
(Laughter)
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(Riure)
11:57
Okay.
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Molt bé.
12:01
Which of course means
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I també vol dir
12:04
we have 10 primary dinosaurs to deal with.
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que tenim 10 dinosaures principals per treballar.
12:08
So a colleague of mine at Berkley,
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Un col·lega meu de Berkeley,
12:10
he and I were looking at Triceratops.
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ell i jo estavem observant el Triceràtops,
12:13
And before the year 2000 --
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i abans de l'any 2000
12:15
now remember,
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(recordeu,
12:17
Triceratops was first found in the 1800s --
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el Triceratops va ser trobat el segle XIX)
12:19
before 2000, no one had ever seen
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abans del 2000 ningú havia vist
12:22
a juvenile Triceratops.
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un Triceràtops jove.
12:25
There's a Triceratops in every museum in the world,
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Hi ha un Triceràtops a cada museu del món,
12:28
but no one had ever collected a juvenile.
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però ningú havia recollit mai un exemplar jove.
12:32
And we know why, right?
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I ja sabem perquè, no?
12:34
Because everybody wants to have a big one.
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Perquè tothom vol tenir-ne un de gran.
12:37
So everyone had a big one.
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I tothom en tenia un de gran.
12:39
So we went out and collected a whole bunch of stuff
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Per tant vam anar a recollir una bona pila de material
12:41
and we found a whole bunch of little ones.
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i en vam trobar una bona colla de petits
12:43
They're everywhere. They're all over the place.
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Estan a tots llocs, per tot arreu.
12:47
So we have a whole bunch of them at our museum.
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I així en tenim una bona colla al nostre museu.
12:49
(Laughter)
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(Riure)
12:54
And everybody says it's because I have a little museum.
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I tothom diu que és perquè tinc un museu petit.
12:56
When you have a little museum, you have little dinosaurs.
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Quan un té un museu petit, un té dinosaures petits.
12:59
(Laughter)
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(Riure)
13:02
If you look at the Triceratops,
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Si mirem al Triceratops,
13:04
you can see it's changing, it's shape-shifting.
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podem veure que canvia, la seva forma canvia.
13:06
As the juveniles are growing up,
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Quan els individus joves creixen,
13:08
their horns actually curve backwards.
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les seves banyes es corben cap al darrere.
13:10
And then as they grow older,
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I quan es van fent més vells,
13:12
the horns grow forward.
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les banyes creixen cap endavant.
13:14
And that's pretty cool.
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Això és força interessant.
13:16
If you look along the edge of the frill,
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Si mirem al llarg de la vora del volant,
13:18
they have these little triangular bones
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tenen aquests petits ossos triangulars
13:21
that actually grow big as triangles
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que creixen grans com a triangles
13:23
and then they flatten against the frill
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i que acaben aplanant-se contra el volant
13:26
pretty much like the spikes do
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més o menys com fan les punxes
13:28
on the Pachycephalosaurs.
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del Paquicefalosaure.
13:31
And then, because the juveniles are in my collection,
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I desprès, com que els individus joves són de la meva col.lecció,
13:35
I cut them open
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Els tallo
13:37
and look inside.
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i hi miro a dins.
13:39
And the little one is really spongy.
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El més petit és realment esponjós.
13:42
And the middle size one is really spongy.
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I el de tamany mig és realment esponjós.
13:45
But what was interesting
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Però el que era interessant
13:47
was the adult Triceratops was also spongy.
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era que el Triceratops adult també era esponjós.
13:49
And this is a skull that is two meters long.
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I aquest és un crani de dos metres de llarg.
13:52
It's a big skull.
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És un crani enorme.
13:55
But there's another dinosaur
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Però hi ha un altre dinosaure
13:57
that is found in this formation
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que trobem en aquesta formació
14:00
that looks like a Triceratops, except it's bigger,
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que s'assembla al Triceratops, encara que és més gran,
14:03
and it's called Torosaurus.
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i que s'anomena Torosaure.
14:06
And Torosaurus, when we cut into it,
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I quan vam tallar el Torosaure,
14:09
has mature bone.
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presentava os madur.
14:11
But it's got these big holes in its shield.
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Però té aquests forats grans a l'escut.
14:13
And everybody says, "A Triceratops and a Torosaurus
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I tothom deia, "Un Triceratops i un Torosaure
14:16
can't possibly be the same animal
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no poden pas ser el mateix animal
14:18
because one of them's bigger than the other one."
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perquè un és major que l'altre."
14:20
(Laughter)
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(Riure)
14:25
"And it has holes in its frill."
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"I té forats al volant."
14:27
And I said, "Well do we have any juvenile Torosauruses?"
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I jo vaig respondre, "Bé, tenim cap Torosaure jove?"
14:30
And they said, "Well no,
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I ells van dir, "Bé... no,
14:33
but it has holes in its frill."
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però té forats al volant."
14:36
So one of my graduate students, John Scannella,
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Així que un dels meus estudiants de grau, John Scanella,
14:39
looked through our whole collection
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va revisar tota la nostra col.lecció
14:41
and he actually discovered
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i va trobar
14:43
that the hole starting to form
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que el forat es començava a formar
14:45
in Triceratops
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al Triceratops
14:47
and, of course it's open, in Torosaurus --
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i, per descomptat, estava ja obert al Torosaure
14:50
so he found the transitional ones
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així va trobar els individus de transició
14:53
between Triceratops and Torosaurus,
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entre el Triceratops i el Torosaure,
14:55
which was pretty cool.
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la qual cosa era impressionant.
14:57
So now we know
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Ara sabem, doncs,
14:59
that Torosaurus
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que el Torosaure
15:01
is actually a grownup Triceratops.
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és de fet un Triceratops més vell.
15:04
Now when we name dinosaurs,
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Ara, quan anomenem els dinosaures,
15:06
when we name anything,
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quan anomenem qualsevol cosa,
15:08
the original name gets to stick
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el nom original tendeix a prevaldre
15:10
and the second name is thrown out.
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i el segon nom és descartat.
15:14
So Torosaurus is extinct.
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Per tant, el Torosaure s'ha extingit.
15:17
Triceratops, if you've heard the news,
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El Triceratops, si heu escoltat les notícies,
15:20
a lot of the newscasters got it all wrong.
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molts reporters ho van entendre al revés.
15:22
They thought Torosaurus should be kept and Triceratops thrown out,
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Van pensar que s'havia de mantenir el Torosaure i descartar el Triceratops,
15:25
but that's not going to happen.
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però això no passarà
15:27
(Laughter)
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(Riure)
15:33
All right, so we can do this with a bunch of dinosaurs.
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Molt bé, llavors podem fer això amb una bona colla de dinosaures.
15:36
I mean, here's Edmontosaurus
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A veure, aquí tenim l'Edmontosaure
15:38
and Anatotitan.
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i l'Anatotità.
15:40
Anatotitan: giant duck.
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Anatotità: ànec gegant.
15:43
It's a giant duck-bill dinosaur.
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És un dinosaure gegant amb bec d'ànec.
15:45
Here's another one.
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Aqui n'hi ha un altre.
15:47
So we look at the bone histology.
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Doncs ens fixem en la histologia òssia
15:49
The bone histology tells us
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La histologia òssia ens indica
15:52
that Edmontosaurus is a juvenile,
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que l'Edmontosaure és jove,
15:54
or at least a sub-adult,
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o com a màxim un sub-adult,
15:56
and the other one is an adult
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i l'altre és un adult
15:59
and we have an ontogeny.
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i ja tenim una ontogènia.
16:02
And we get rid of Anatotitan.
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I ens desempelleguem de l'Anatotità.
16:05
So we can just keep doing this.
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I podem seguir fent això.
16:08
And the last one
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I l'últim
16:10
is T. Rex.
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és el T. Rex.
16:12
So there's these two dinosaurs,
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Aquí tenim aquests dos dinosaures,
16:14
T. Rex and Nanotyrannus.
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T. Rex i Nanotirà.
16:17
(Laughter)
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(Riure)
16:19
Again, makes you wonder.
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De nou, fa rumiar.
16:22
(Laughter)
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(Riure)
16:25
But they had a good question.
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Però tenien un gran misteri.
16:27
They were looking at them
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S'els miraven
16:29
and they said, "One's got 17 teeth, and the biggest one's got 12 teeth.
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i deien, "Un té 17 dents, i el més gran en té 12.
16:32
And that doesn't make any sense at all,
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I això no té sentit,
16:34
because we don't know of any dinosaurs
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perquè no sabem de cap dinosaure
16:36
that gain teeth as they get older.
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que guanyi dents en fer-se vell.
16:38
So it must be true --
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Per tant, deu ser veritat:
16:40
they must be different."
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deuen ser diferents."
16:43
So we cut into them.
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Per tant els vam tallar.
16:45
And sure enough,
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I amb tota certesa,
16:47
Nanotyrannus has juvenile bone
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El Nanotirà presenta os jove
16:50
and the bigger one has more mature bone.
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i el més gran té ossos més madurs.
16:53
It looks like it could still get bigger.
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Sembla com si encara es pogués fer més gran.
16:56
And at the Museum of the Rockies where we work,
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I al Museu de les Rocalloses, a on treballem,
16:58
I have four T. Rexes,
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tinc quatre T. Rex,
17:00
so I can cut a whole bunch of them.
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per tant en puc tallar una bona colla.
17:02
But I didn't have to cut any of them really,
384
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Però de fet no vaig haver de tallar-ne cap ni un,
17:05
because I just lined up their jaws
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perquè tan sols vaig comparar les seves mandíbules
17:08
and it turned out the biggest one had 12 teeth
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vaig veure que el més gran tenia 12 dents
17:11
and the next smallest one had 13
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i el següent més petit en tenia 13
17:13
and the next smallest had 14.
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i el següent més petit en tenia 14.
17:15
And of course, Nano has 17.
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I, evidentment, el Nano en té 17.
17:17
And we just went out and looked at other people's collections
390
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I tan sols vam sortir a mirar les col·leccions d'altra gent
17:20
and we found one that has sort of 15 teeth.
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i vam trobar-ne un que tenia com 15 dents.
17:24
So again, real easy to say
392
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De nou, és fàcil imaginar
17:27
that Tyrannosaurus ontogeny
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que la ontogènia del Tiranosaure
17:29
included Nanotyrannus,
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incloïa en Nanotirà,
17:32
and therefore we can take out another dinosaur.
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i per tant ens podem carregar un altre dinosaure.
17:37
(Laughter)
396
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(Riure)
17:39
So when it comes down
397
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Així que cap al final
17:43
to our end cretaceous,
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del Cretaci,
17:45
we have seven left.
399
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ens en queden set.
17:48
And that's a good number.
400
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I aquest és un bon nombre.
17:51
That's a good number to go extinct, I think.
401
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Penso que és un bon nombre per extingir-se.
17:54
Now as you can imagine,
402
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Com podeu imaginar,
17:56
this is not very popular with fourth-graders.
403
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això no serà gaire popular entre els nanos.
17:59
Fourth-graders love their dinosaurs,
404
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Els nanos adoren els seus dinosaures,
18:01
they memorize them.
405
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memoritzant-los.
18:06
And they're not happy with this.
406
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I això no els agrada gens
18:09
(Laughter)
407
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(Riure)
18:11
Thank you very much.
408
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Moltes gràcies.
18:13
(Applause)
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(Aplaudiments)
ABOUT THE SPEAKER
Jack Horner - Dinosaur diggerJack Horner and his dig teams have discovered the first evidence of parental care in dinosaurs, extensive nesting grounds, evidence of dinosaur herds, and the world’s first dinosaur embryos. He's now exploring how to build a dinosaur.
Why you should listen
Paleontologist Jack Horner discovered the first dinosaur eggs in the Western Hemisphere, the first evidence of dinosaur colonial nesting, the first evidence of parental care among dinosaurs, and the first dinosaur embryos.
Horner's research covers a wide range of topics about dinosaurs, including their behavior, physiology, ecology and evolution. Due to struggles with the learning disability, dyslexia, Horner does not hold a formal college degree but was awarded an Honorary Doctorate of Science from the University of Montana in 1986. Also in 1986 he was awarded a MacArthur Fellowship.
He's the Curator of Paleontology at the Museum of the Rockies in Bozeman, Montana, and is widely acknowledged to be the inspiration for the main character in the book and film Jurassic Park.
Jack Horner | Speaker | TED.com