The Dinosaur On Your Dinner Table

The Dinosaur On Your Dinner Table


Hey smart people, Joe here. This holiday season, I bet many of you are
going to be sitting down with family and friends to celebrate. And I bet a lot of you are going to be eating
some nice delicious… dinosaur! Birds are dinosaurs! But why is that? That’s what we’re going to talk about
today. [OPEN] Today I’m here with my friends Anna Rothschild
who makes Science Magic Show Hooray! at The Washington Post, and… fun fact, she’s
25% mashed potatoes. It’s true! I am. And Dr. Shae Montanari, who is not only a
pumpkin beer aficionado, but is a dinosaur expert extraordinaire. Really happy to be here, Joe So we have all heard that birds are dinosaurs,
but what exactly does that really mean? The way that we can tell that anything is
related to something else is by looking at their anatomy and what kind of characteristics
that they share. These are called synapomorphies, traits shared
by two or more groups of organisms, and derived from a common ancestor. Like how humans and chimps both have opposable
thumbs. So, there’s different kinds of dinosaurs
and we can look at the characteristics of birds to find out exactly what kind of dinosaurs
they are. There’s actually lots of clues preserved
in their bones that show that they are very closely related, and that birds are actually
dinosaurs. And we’re gonna find those today, with this! So, we couldn’t get a turkey, it’s not
quite Thanksgiving yet. But everything we show you we promise you
can do at your holiday table with the people you’re celebrating with, and explain to
them the science of why you’re eating a dinosaur. VO: In the 1860s, scientists unearthed the most
famous feathered dinosaur fossil: Archaeopteryx. Early defenders of evolution like Thomas Henry Huxley began
to suggest that these extinct reptiles were so similar to birds, they must be related. But the idea didn’t really catch on until
the 1970s, when new fossils filled in more empty branches on the dinosaur family tree… VO: About 250 million years ago, a group called
Archosaurs split into Crocodilian reptiles, and Dinosaurs. And a lot of evolution has happened since
that split. Ok, so there’s two groups of dinosaurs,
and that’s the Ornithischian and the Saurischian dinosaurs. And that split happened about 240 million
years ago. And the way we know that birds belong to the
Saurischian group is mainly because of their hands. Wait, hands? A: Birds don’t have hands! S: Birds actually DO have hands, they just
don’t really look like hands anymore. If you’ve ever eaten a chicken wing, or
held on to a chicken wing, you’ve been shaking hands with a chicken! Can we dig into this chicken and check it
out? I think it’s time to check it out. Let’s go find a chicken hand. A: So these are like the original chicken
fingers! —
J: I usually dissect these with my teeth, you’re doing it completely differently
So that little skinny part of the wing, at the end, that you don’t typically eat… This little nubbin? That little nubbin, is the finger of the chicken,
that’s gotten super reduced. I accidentally broke off the very tip of the
bird finger, but here is like, the second digit. The very, very tip of the finger. It’s a tiny bird finger. Joe, I’m going to let you hold that as well! The length of the three bird fingers inside
a wing narrows down which group of dinosaurs birds descended from The second finger is longest in birds and
in Saurischian dinosaurs. That’s a big way we know that birds belong
to the Saurischian group as opposed to the Ornithischian group. So birds are Saurischian dinosaurs, but are
all Saurischian dinosaurs birds? S: No, they are not. That’s a great question. So even within Saurischian dinosaurs, as we’re
walking up this dinosaur family tree, there’s another group that branches off and we can
tell which one birds are a part of, and it’s the Theropod dinosaurs. S: And the one bone that is the biggest clue
of Theropod dinosaurs is something that you’ve probably played a little game with after your
thanksgiving dinner: The wishbone! Right here. Cooool! —
I think it’s time to dissect a wishbone. What does the wishbone do? Does it serve a purpose for flight or for
something else? It helps birds get their wishes! Oh right, of course! Besides helping all their dreams come true,
the furcula is actually support for the flight muscles. A wishbone, or “furcula”, is actually
a bird’s collarbones, but instead of two separate collarbones like we have, theirs
is fused into one. Wishbones have only been found in birds and
Theropod dinosaurs, like Allosaurus, and they draw a clear line from those extinct creatures
to our modern feathered friends. J: Ok let’s get this wishbone out in one
piece. This is nerve wracking. I got it! S: You did it! A: Bravo! —
J: So all birds will have a form of this, and all dinosaurs in this part of the tree
also had something like this? S: We’ve found a furcula in most Theropod
dinosaurs’ fossils that we’ve found around the world. —
J: We’ll save this for later. VO: Fossil wishbones are one of the most important
pieces of evidence we have that birds descended from Theropod dinosaurs. S: So actually one of the similarities between
birds and theropods, and how we know that birds are theropod dinosaurs, is inside their
bones. S: This is another one of those tibiotarsus
bones… J: Drumstick bones! S: Drumstick bones, and I have channeled all
of my rage and broken this one in half, and look inside, and you can see that the walls
of the bone is very thin and basically hollow. So when people say that birds have hollow
bones, that’s what they mean. There’s very little spongy bone on the inside,
and there’s a very thin wall, which makes it easier for them to fly. J: Theropod dinosaurs had these hollow bones
too. So did that help them be more agile, you know,
go in for more Jurassic Park type kills? S: Right, that’s a great question. Because theropods had a lot of the characteristics
that modern birds do, but they didn’t fly. So these characteristics must have been helpful
for them to do other things. And hunting is definitely one of them. J: That’s the cool thing about evolution,
is that something that could have helped theropods that didn’t fly in one way, birds could
have taken advantage of that in a completely different way as light weight for flight,
right? S: Exactly! S: So even within Theropods, as we’re going
down the family tree, there’s more branches, and the way we can tell which one birds fall
in is how many fingers they have. VO: Around 200 million years ago, Theropods
split. One branch kept four or even five fingers,
but a branch called Tetanurae all descended from an ancestor with just three fingers. Our bird? Three fingers! Later, some Tetanurans, like T. rex, even
lost an additional finger, going from three to two! Poor T. rex. J: So our chicken, we’ve got one, two, three
fingers. —
S: Ok, so to get to the next identifying characteristic of this bird, we’re really gonna have to
dig in there. J: I’m just ripping parts off here. It’s so… it’s kinda fun actually. It’s like The Brain Scoop crossed with a
cooking show right now. A: For sure. S: Oh man. A: I mean honestly, this entire scene is so
macabre. S: It’s so bad. J: It’s awesome. The darkest thanksgiving! J: You can do any of this with a turkey, it’s
just going to be a lot messier. Which in my book, makes it more fun. —
A: So we know that birds are Tetanurans, but can we get even more specific? S: We can get even more specific. There’s a few more branches to go, before
we get to what we call “crown birds” or living birds. And birds are a specific kind of theropod
called Maniraptoran theropods. So Maniraptora, one of the characteristics
of this group is that the hips point backwards. Specifically, the rearward-tilted bone is
a part of the pelvis called the pubis. J: So we’ve got our backward facing pelvis
for the maniraptorans. Is there another branch beyond this? S: Yeah, there’s still more branches to
go, -but the one we’re going to end on is Avialae. So Aves is part of Avialae. Aves is modern birds
So a big difference between the kinds of theropod dinosaurs that you’re probably envisioning
In your head, like Velociraptor, and birds, is a tail. So birds actually do not have tails. This little bit at the end represents what’s
left of the dinosaur tail, called a pygostyle. So the pygostyle is the last remnants of a
long fluffy feathered theropod tail, and narrows down the bird/dinosaur family tree even further. So. Birds are
Avian Maniraptoran
Tetanuran So. Birds are
Avian Maniraptoran
Tetanuran Theropod
Dinosaurs. And these anatomical features are just a few
of the similarities that scientists have used to place birds in the dinosaur family tree. There’s even more, from the shape of their
necks, to their weird feet, to yes, even feathers. J: Ok, my holiday dinner is never gonna be
the same. It’s gonna be way awesomer, and a little
grosser. But that’s ok. S: So if you want to do this at home, you
definitely can, and if you want to learn more, there’s links in the description. J: You know we’ve taken a deep dive inside
of a dinosaur to see what makes them what they are, but what were they like on the outside? What did they act like? A: That is an excellent question! And if you want to learn more about what colors
dinosaurs were, or even what sounds they made, head on over to my channel where Joe and I
explore those questions. J: Ok, like every holiday dinner, this one
has to end with the traditional breaking of the wishbone. Grab a side guys. 3-2-1… A: What did you wish for? S: I wished for everyone to stay curious!

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