Jane: This is But Why: a Podcast for Curious Kids from Vermont
Public. I'm Jane Lindholm. On this show, we take questions
from curious kids just like you, and we find answers. We've
gotten thousands of questions, and hundreds of them are about
dinosaurs. We took a really cool field trip to Texas a few years
ago to look at some newly uncovered dinosaur footprints in
a dry riverbed and to make an episode all about these
prehistoric beasts. But that only scratched the surface of
all the questions we've gotten about dinosaurs. So today we're
going to tackle a chunk more of them, and we're going to be
doing it with a paleontologist.
Emily: My name is Dr. Emily Bamforth. I am a paleontologist
and the curator of the Philip J. Currie Dinosaur Museum. So
paleontology is actually, it's a pretty broad field. There are
paleontologists that just study dinosaurs, but paleontology is
actually the study of fossils. So anything that fossilizes gets
studied by paleontologists. So whether that's bugs or plants or
fish or even bacteria, anything that was alive and is now dead
and fossilized, that's what paleontologists study.
Jane: Emily Bamforth does study dinosaurs and all the things
that lived with them from her home base in Alberta, Canada.
Emily: That includes going out and finding them, digging them
up, bring them back to museum, preparing them and taking care
of those collections once they're in the museum, and then
telling the world about all the stuff we found.
Jane: Emily fell in love with dinosaurs when she was just four
years old, and saw her first dinosaur exhibit. So if you're a
dino loving kid, you should know there's a field of study for you
as you grow older. Dinosaurs first appeared on earth about
245 million years ago, give or take, a few million years. Then
they lived for a long, long time. But not all dinosaurs
lived at the same time as each other. Just as there are animals
that have gone extinct more recently, there were dinosaurs
that went extinct or evolved over time. And it's also
important to remember that not all of the animals living back
then were dinosaurs,.
Emily: Yeah, that's right. And there are some animals that are
actually called dinosaurs that are not. So the plesiosaurs that
lived in the ocean and the big mosasaurs kind of other marine
reptiles, they sometimes get called dinosaurs, but they
weren't. They belong to a different group of reptiles, but
because they lived at the same time as dinosaurs, they
sometimes are accidentally called dinosaurs. It's the same
with things like the pterosaurs, the things like pterodactyls and
pteranodon those things are actually not dinosaurs either.
They belong to a different group of reptiles, but again, they
lived at the same time as dinosaurs, so they sometimes get
lumped in there, but dinosaurs are actually very specific group
of reptiles. But of course, they weren't the only ones living at
Jane: There were crocodiles, horseshoe crabs, mammals, plants
and insects living in the time of the dinosaurs. But let's back
up a second and consider this question from Willow.
Willow: I'm five years old. I live in New York City, why are
dinosaurs ancestors and what are dinosaurs ancestors ancestors?
Emily: Based on what we know from the fossil record, we think
that dinosaurs and crocodiles had the same ancestor, so the
ancestor of dinosaurs probably looked like a crocodile, maybe
like a little bit of a skinny crocodile that maybe could have
gotten up and walked on two legs. So some of our very early,
early dinosaurs, back when dinosaurs first appeared, they
look a little like crocodiles, but crocodiles that walked on
two legs. And so before that, we know that dinosaurs are
reptiles. So they came from the, basically the same group of
animals that are lizards and snakes and crocodiles and
turtles came from today. So basically from from a reptilian
ancestor, we got, like a crocodilian like ancestor, and
from those, those crocodile like things, we got the dinosaurs and
then the birds.
Jane: So that kind of answers Amos's question.
Amos: I live in Massachusetts. I'm six years old. Are there any
dinosaurs that are mammals?
Emily: Dinosaurs are reptiles and mammals are mammals. They're
actually different types of animals. There were mammals
around at the same time as dinosaurs, and so sometimes it's
easy to forget, but there's actually a lot of mammals that
lived at the same time of dinosaurs. Mammals just didn't
really kind of get big until after the dinosaurs went
extinct. But they were certainly there. Mammals actually predate
dinosaurs.
Olive: Hi, my name's Olive. I live in Melbourne Australia. I'm
7 years old. If crocodiles are dinosaurs, why are they not
extinct?
Emily: The closest ancestor or the closest relative of a modern
bird is actually a crocodile, and so dinosaurs and crocodiles
were reasonably closely related, but crocodiles today, just as
the dinosaurs and the birds kind of went off on their own branch,
modern crocodiles went off on their own branch too. And so
even though crocodiles are really ancient animals, they've
also been around for a long time, they've also kind of
evolved on their own branch. And so crocodiles, again, they've
been around for a long time, but it's not the same crocodiles
that live today as the ones that lived in the fossil record. They
have changed and evolved the same way that dinosaurs have.
Jane: So crocodiles and birds are actually more closely
related to each other than crocodiles and lizards, right?
Emily: That's right, yeah. So they crocodiles and dinosaurs
and birds belong to a group called the archosaurs. They
basically have their own group all to themselves, and then our
lizards and our turtles and our snakes are on another branch of
the reptile tree.
Jane: When you think about evolution, remember, we're
talking millions of years so animals can share ancestors and
not look anything alike. Now you might have been surprised to
hear that dinosaurs and birds and crocodiles are all related.
More on that in just a minute. But if you know anything about
dinosaurs, you've probably heard that they went extinct about 66
million years ago.
Amelia: Hi. My name is Maya from Monterey, California. Why are
dinosaurs extinct?
Jagger: My name's Jagger. Why did dinosaurs live 60 million
years ago and not now?
Kinley: My name is Kinley. I am seven years old, and I live in
Clive, Iowa. Why were dinosaurs extinct?
Sebastian: My name is Beatrix. I'm five years old. I live in
Ohio. Why are dinosaurs extinct, including my favorite one, the
Brachiosaurus.
I'm Sebastian and I'm 5 years old. Why did the dinosaurs go
extinct?
Evie: Hello, I'm Evie. I'm five years old. I live in Kansas, and
my question is like, why did the dinosaurs and other reptiles
that didn't survive the meteor when alligators and cockroaches
did?
Noah: My name's Noah, and I'm five years old and I'm from
mobile Kentucky, when were the dinosaur extinct?
Amelia: Hello. My name is Amelia. I am six years old, and
I am from Washington, DC, and I want to know, how did the
asteroid make the dinosaurs go extinct?
Lucas: My name is Lucas. I live in Germany, and I am seven years
old. My question is, how do trees come back after dinosaurs
were extinct?
Ava: Hi, my nickname is Ava. I'm eight years old, and I live in
Florida, and my question is, why did the asteroid make the
dinosaurs extinct, but it didn't cover the whole earth?
Hannah: My name is Hannah. I live in San Diego, California,
and I'm four years old. And my question is, why do dinosaurs
don't live so much?
Emily: So the dinosaur mass extinction it is has been a huge
debate for a really long time. And I remember when, when I was
a kid, it was still very much a question about what killed the
dinosaurs. And there's been a lot of work that's been done,
pretty much since the 1980s that now we've we've pretty well
established that the big thing that caused that extinction was
a meteorite impact, or what geologists would call a bolide
impact, basically a giant piece of space rock came in and hit
the Earth, probably around the Yucatan Peninsula in Mexico, and
basically caused a whole bunch of bad things to happen all at
once. So like forest fires and acid rain and earthquakes and
volcanic eruptions. And would have been a very bad day on
planet Earth. So we think that that event probably almost
instantly wiped out the big dinosaurs, at least in North
America, and after that happened, their ecosystem, so
kind of all of the you know, the things that were happening
around them also collapsed. And so we know from the mass
extinction that nothing big survived. So nothing bigger than
basically, like a golden retriever dog survived. So all
the big things went extinct. They just didn't have the food,
they didn't have the resources, they didn't have the habitats
they needed anymore, and then there probably would have been
what we call a nuclear winter, so all of that ash and the
ejecta from that big meteorite impact would have blocked out
the sun, so that would have affected the plant communities,
and so the animals that relied on those plants would have died
as well.
Jane: That certainly sounds terrible! When we think about
this time period. It's often called a mass extinction event,
when lots and lots of animals and plants died. But it's
important to remember that a lot of plants, animals and insects,
also survived.
Emily: So we think the things that survived the mass
extinction were small. They were able to eat a whole bunch of
different things. So they were what we call generalists, so
they could eat seeds and they could eat plants, and they could
maybe eat detritus, and they could eat insects so they were
able, they didn't didn't starve, because they could eat a bunch
of different things. And then animals that had some kind of
way to escape the after effects. So if they lived in water, or if
they lived underground, they tended to do pretty well. So for
example, turtles did really well out of the mass extinction. Most
turtles survived the mass extinction, because most turtles
live in water, so they were able to go into the water and hide.
The early birds, so there were birds around at the time of the
extinction, and we think the ones that survived were the ones
who were able to eat seeds. So seeds are something that doesn't
necessarily rely on the sun. So they can, they can, seeds can
hang out on the surface for a long time. So birds that were
able to eat seeds did pretty well. And then there were some
animals that were just lucky. So I think in in terms of what
survives a mass extinction, whether it's the dinosaur mass
extinction or one of the four mass extinctions before that, it
just seems that there were some animals that just got lucky, and
they managed to survive, and they became really, really
diverse afterwards.
Jane: And what else survived the mass extinction that killed off
so many of the dinosaurs that we can point to, as you know,
ancestors of modern animals today?
Emily: Yeah, so the crocodiles survived the mass extinction. So
crocodiles actually were around even, even in places like Canada
for a long time after, after the dinosaur mass extinction, and of
course, the mammals. So the mammals at the time, there were
some slightly bigger ones, but most mammals were really small,
so they were able to go underground or live in trees.
They could survive the effects of that meteorite impact. And
they obviously become really, really abundant and fill all
kinds of niches. Mammals get really, really big after the
extinction. So mammals are basically one of the great
survivors. And birds of course, and of course are, you know,
these living we call them living fossils. So things like sharks.
Sharks are still with us today. Sharks have been around pretty
much forever. Some of the groups of fish that live in the oceans,
some of the amphibians, the salamanders, the frogs, survived
the mass extinction as well. So basically, everything we see
today in our world survived the mass extinction.
Jane: You mentioned that some of the animals that could survive
that mass extinction and the effects of the meteorite were
animals that could hide or get away, or had specific foods that
they ate that they could still eat. And Grayson would love a
little more explanation.
Grayson: I am seven and and I live in Flagstaff, Arizona. How
did some bird dinosaurs survive the meteor?
Emily: Yeah, so at the time of the dinosaurs, there were what
we would consider true birds. They looked a little different
than birds today. They had teeth, for example, and they had
bony tails, like dinosaurs did, but otherwise they probably
would have looked a lot like birds. So of course, they were
small the ones that survived. So the small bodied ones, the
smaller you are, the better your chances of surviving a mass
extinction. So most of those, those birds were small, and they
could also, we think, eat a whole bunch of different things.
So birds can eat seeds, they can eat insects. There's some, not
many, but there's some herbivorous birds as well. They
could eat fish. Some birds today, like like vultures, eat,
carrion, you get things that are already dead. So those birds
that survive probably had a range of diets that they could
eat, and birds can also fly. So they could actually get out of
those areas. If it was really bad where they were living, they
could fly away and find a better place. And that was definitely
something that, you know, something like a triceratops
would not be able to do. So we think those are probably the
reasons why the birds survived. Birds, of course, were also warm
blooded, so even though it got really, you know, really cold,
they could probably find a way to warm up. So lots of
adaptations that that meant that a lot of those groups of birds
survived.
Jane: So there were already birds living in the time of the
dinosaurs. But if you've been following dinosaur news over the
course of your lifetime, you already know that birds are
dinosaurs. Stay tuned. We'll explain.
This is But Why: a Podcast for Curious Kids. I'm Jane Lindholm,
and today we're talking dinos with Canadian paleontologist Dr
Emily Bamforth. We were just talking about a mass extinction
event about 66 million years ago that wiped out tons of animals,
including most of the dinosaurs, but there are animals walking,
well, flying among us today that are essentially living
dinosaurs. Let's get into it.
Alice: Hi, my name is Alice. I live in Columbia, Maryland, and
I'm eight. How are birds and dinosaurs related?
Emily: Yeah, so really good question, and this is something
that paleontologists have really only just figured out in the
last kind of 20 or 30 years, and now if you look at a bird, it's
sort of easy to see a dinosaur, like if you look at a bird's
foot, birds have got scaly feet, like dinosaurs, like other
reptiles, and they have claws like like dinosaurs would have
as well. So we now know that a lot of dinosaurs also had
feathers. And so we actually know that now, not only we know
that they're related, birds are actually dinosaurs. Birds are
the dinosaurs that didn't go extinct in that mass extinction.
And there's a whole lot of different lines of of, lines of
evidence, ways that we can tell that by looking at the fossil
record, but dinosaurs are actually still among us in in
the form of birds. And that is kind of mind blowing, and that
totally changed how paleontologists looked at
dinosaurs.
Jane: Birds are dinosaurs.
Emily: Yeah. So that's kind of the way that not only
paleontologists, but biologists kind of think about life. And
so, for example, humans are mammals, and we're not the only
mammals. There's whole lot of mammals out there. And the thing
that makes us mammals is we have a series of of shared
characteristics. Basically, like, we have hair and we give
birth to life young, and we like, feed the young with milk.
That's what kind of things that makes mammals mammals. But we
all have the same ancestor, like we all have the same like,
great, great, great, great, great, great mammel grandparent,
and because we all came from that grandparent that makes us
all mammals, and I was the same with dinosaurs. So like,
dinosaurs are kind of the great, great, great, great, great
grandparents of birds. And so because they're related, they
have kind of that connection through their their ancestry.
That's what makes them into into dinosaurs, is that they're
related through all of the, you know, all of that geologic time,
and they also have all of those same characteristics. So birds
and dinosaurs that share a lot of things that are the same.
Jane: Remember, most of the dinosaurs that ever existed went
extinct. So not all dinosaurs evolved into birds. You could
kind of say it like this, all birds are dinosaurs, but not all
dinosaurs became birds.
Emily: The dinosaurs that are closely related to birds. Most
closely related are what we call theropods, and those are
basically bipedal, carnivorous dinosaurs.
Jane: Bi-pedal meaning, walks on two feet and carnivorous, eats
meat.
Emily: That's right, so walked on two legs and ate meat. So
those dinosaurs like Velociraptor or dromiosaurus,
even things like T Rex, Albertosaurus, basically that
group of dinosaurs are closely related to birds and things like
Triceratops and the duck billed dinosaurs and the stegosaurs and
the ankalosaurs, even though they're dinosaurs, they're less
closely related to birds.
Jane: Okay, so if some dinosaurs evolved into birds, did
dinosaurs have feathers?
Charlie: My name is Charlie. I live in Western Massachusetts. I
am eight years old. My question is, how do we know some
dinosaurs had feathers?
Hannah: Hello. My name is Hannah Luis. I am 10 years old, and I
am from South Korea in Daegu. How do people know dinosaurs had
feathers.
Emily: The reason that we know that dinosaurs had feathers is
because we have found dinosaur skeletons with the feathers
still attached. So the most famous, or the very first one
that was found, was the Archaeopteryx. So that was found
in Germany, and when they found it, this is kind of a great
story. When they originally found it, they could see it was
a dinosaur skeleton and that it had all these weird kind of
features in the rock around it, and they actually started to
erase them, because they didn't know what they were. They
thought it was just maybe like a weird thing that was happening
in the rock. And it wasn't until they went more closely that they
realized that these were feathers and that this, at the
time, they called it an ancient bird. We now know that is
basically a feathered dinosaur. And so that that happened like
early in the 19th century, and then it really wasn't until they
found feathered birds in China. China's really well known for
its feathered dinosaurs, and that's when they first really
started to make the link between birds and dinosaurs, because
they're actually finding dinosaurs with feathers.
Jane: And when was that? I mean, you were saying this is only in
the last couple of decades, because when I was a kid, which
was a long time ago, but not as long as the dinosaurs were alive
ago, we didn't talk about it that same way, right?
Emily: And it's actually something that's happened in my
lifetime as well. So here I was, this, like dinosaur crazy kid.
And I remember, I was maybe around 10 years old when the
first the story of the feathered dinosaurs from China really
started to kind of hit the press, and you start to see it
in in books and magazines. And it was really, really exciting.
So that was actually in the 1990s so it's, well, I mean, for
me, fairly recent, but again, it's something we've really
started to figure out. In the last 20 or 30 years or so,
Jane: Scientists had had theories for a while that
dinosaurs and birds were related, but in the 1990s
thousands of feathered dinosaur fossils were found. These bird
like dinosaurs, lived alongside those other dinosaurs for a
million years. When the asteroid hit Earth, these avian dinosaurs
survived, and that might explain a lot about dinosaurs and eggs.
Kadence: Hi, my name's Kadence. I'm three and a half years old.
I live in Bellevue, Washington. Why do baby dinosaurs come from
eggs?
Emily: All dinosaurs, as far as we know, laid eggs. Dinosaurs
laid eggs basically because their ancestors laid eggs. So
dinosaurs, that whole group of animals, is kind of related to
they had, kind of a crocodilian, so an ancestor looked a little
bit like a crocodile, and that ancestor laid eggs as well. And
so dinosaurs laid eggs because their ancestors laid eggs, and
they really had no reason to change from laying eggs. So of
course, birds today do because dinosaurs did, because the
dinosaur ancestors did.
Audrey: My name is Audrey, and I live in Arlington, Virginia, and
I'm five years old. What are dinosaur eggs made out of?
Emily: Dinosaur eggs are probably made of the same thing
that bird eggs are. So basically just made out of calcium, or
kind of a calcium sort of complex and so dinosaur eggs,
from what we know in the fossil record, probably very similar to
bird eggs, except they're probably a little bit thicker,
because dinosaur eggs, a lot of them, are a lot bigger than bird
eggs today.
Jane: Some bird eggs, like an ostrich egg, are pretty thick,
right? You wouldn't necessarily break them by just squeezing it
in your hand, so maybe kind of like that.
Emily: Yeah. So we're pretty sure that we know that dinosaur
eggs were hard. So there are some reptiles that actually have
soft eggs, like turtle eggs are soft, but dinosaur eggs were
probably hard, like a bird egg, and the bigger they were,
probably the thicker that egg shell was.
Jane: Did you hear Emily Bamforth say, we're pretty sure
we know that dinosaur eggs were hard. They don't know for
certain, because eggs aren't preserved very easily, but
they're learning things all the time about dinosaurs and what
they looked like and how they moved and behaved. There are a
lot of things still to learn.
Emily: We have lots and lots of questions about dinosaurs, and
this is why it's great to be a paleontologist where there's no
shortage of questions. So one of the big ones that I'm dealing
with in my research right now is trying to tell the difference
between a male and a female dinosaur. It's really, really
hard to do, because unlike mammals, where, if you look at a
mammal skeleton, it's kind of easy to tell a male from a
female, because the hips are different. But dinosaurs laid
eggs, there's actually very little difference between the
hips of male and female dinosaurs, and we just don't
have enough skulls, enough skeletons, to really know which
which skull is a male skull and which skull is a female skull.
So where, where I work here, we have a big bone bed of an animal
called a pachyrhinosaurus, and we have a bunch of skulls, and
even though we've got a bunch of skulls, we still can't tell the
males from the females. And that's something we'd really
like to do, because that would tell us about how these, if we
have a herd of dinosaurs, like, is it males and females and
equal are they like elephants, where it's like mostly females
in the group, and, you know, they just have one big male with
them. So these things we don't know. So a lot of that
behavioral aspect of dinosaurs we would like to know more
about. It's really hard to study it in the fossil record. And of
course, we're looking for new dinosaurs. There's between kind
of 700 and 1,000 species of dinosaurs known today. But if
you think of how many animals species are on the planet today,
we know that there's, there's 10s of 1000s of more dinosaur
species that we know nothing about. So we would love to find
those as well. So there's still lots and lots of questions.
Dinosaur skin is another one, like the color of dinosaurs. We
we know a little bit about, like, the feathered dinosaurs,
what color they were, but things like triceratops, T Rex, we
still don't know very much about colors there, either. So there's
still lots and lots of questions out there.
Jane: You're in Alberta, Canada. Is that a hot spot for
dinosaurs?
Emily: Yeah. So Alberta is known for its its dinosaur fossils,
and it actually has the same kind of the same sort of rocks
that are in places like Montana and Wyoming and the Dakotas. And
the reason that there are fossils there is is basically
because of an ancient seaway that used to cut through the
middle of North America, and dinosaurs used to live on the
coast of that seaway and because that was a good place to live if
you were dinosaur, but it was also a good place to die if you
wanted to get fossilized. That's why those areas actually have a
lot of dinosaur bones. But there are fossils everywhere,
certainly everywhere in North America, you may not find
dinosaurs, but you might find things like ice age mammals. You
might find fossil fish, fossil shells, fossil leaves. So pretty
much every area of North America has got fossils of some kind. So
you just really kind of have to know what you're looking for.
Jane: You mentioned the pachyrhinosaurus. Can you tell
us about Big Sam, who is one pachyrhinosaurus that you have
helped dig out.
Emily: Big Sam is the, the first skull that has been collected
from our bone bed here. It's called the Pipe Stone Creek bone
bed. It was the first skull collected in almost 20 years.
And it was really cool to find because it was, it was, it's
huge. It's a huge skull for a pachyrhinosaurus, and it's
relatively complete. So pretty much the whole head is there.
Jane: If you were holding it. How big is it?
Emily: It's about a meter and a half long and pachyrhinosarus
have with this big, huge, bony bump over their nose called a
boss. So the boss is almost a meter wide as well. So this
thing is absolutely enormous.
Jane: So you couldn't pick it up by yourself without worrying
about dropping it.
Emily: Oh, no, it, it weighs almost 500 pounds. So it was, it
was a big job to get it out of the ground. We had to use that
like a shop crane, and then we needed, like, like a hydraulic
lift to get it off the ground. And it took us from the better
part of two years to actually get to get out of the bone bed,
and now it's currently in our preparation lab, and it'll be
probably another 12 months or so before it's ready to be
displayed and to be studied. But yeah, certainly, one of the the
coolest things I think I've ever found in the bone bed was this
big, big, giant skull.
Jane: What does it feel like when you start to think, Oh, I
think that's, yes, it is, oh my gosh, it is something like, what
does it feel like in your body?
Emily: So it, it is actually like, like, an adrenaline rush.
Like, you know, your heart is pounding, and you get so, so
excited. And I remember when we found Big Sam because the skull
was actually flipped upside down, so the roof of the mouth
was pointing up. And that's not a way you expect to find a
skull. And we, we found a few little bits and pieces, and we
thought it was, it was just isolated bits of skull that were
kind of scattered around. And then I remember towards the end
of the season, we found the palette, like the roof of the
mouth, and it was connected to all of these things. And we're
like this, this is actually a real skull, like a skull that is
put together. And again, it is, it is an adrenaline rush, like
your like, heart is pounding, and it's, it's so, so exciting.
And then you step back and you're like, oh, well, now we
actually have to get this thing out of the ground without
breaking it, which is the next step.
Jane: Can you imagine being the person like Emily who finds a
dinosaur skull and then gets to work on it, and once it's out of
the ground, there's still so much studying to be done and
research to connect that one animal skull to what's known
about this type of dinosaur, or to learn something new that's
never been realized before. No wonder so many of us are
fascinated by dinosaurs and want to be paleontologists when we
grow up, there is still so much to discover about the world that
existed millions and millions of years before we did. That's it
for this episode. Thanks to Dr. Emily Bamforth, museum curator
at the Philip J. Currie Dinosaur Museum in Alberta, Canada, as
always, if you have a question about anything, have an adult
record, you asking it on a smartphone using an app like
voice memos, then have them email the file to
questions@butwhykids.org. But Why is produced by Sarah Baik,
Melody Bodette, and me, Jane Lindholm at Vermont Public and
distributed by PRX. Our video producer is Joey Palumbo, and
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an all new episode until then, stay curious.