You're listening to Weird and Dead, the paleontology podcast
that tells evolutions most embarrassing and bizarre
stories. I'm Amy Atwater.
And I'm Megan Wetherell, and we are two living scientists who
are really excited about dead things.
This week is all about brain fossils.
Brains made of sand of putty and also those made by a computer.
We will tell you all about an insane fossil brain bonanza in
West TX and stumble through medical terms for tissue that
doesn't usually fossilize. Flocculus.
And of course, we talk about Tilly Edinger, the
paleontologist who figured out what brain fossils were good for
in the first place. Like always, our podcast talks
about some disgusting stuff Blocculus, so please read
through the content warnings before continuing.
OK, today we are going to start out on a story about the best
animal in the world, oriadonts. Oriadonts are awesome because I
study them, but they're also awesome because they're
extremely weird little hooved mammals.
They're all extinct, and it's very, very sad, but they're very
cool, and they're found in one of the coolest paleontological
places in the world, which is West TX.
So in West TX there are a lot of different fossil beds.
Amy and I have both done some research together at them.
I don't think we've actually been to this particular one.
And a lot of that was collected during the 70s.
And just like I'm shocked that like there hasn't been much more
work there. But we're going to talk today a
lot about brains. And we're going to start with a
conversation about Oriodont brains.
And specifically, there's a place in West TX called Reeves
Bone Bed. It's in the chamber's tough
formation. It's Eocene, and it's about 80
feet by 20 feet with a thickness of three feet deep.
And it was described by Wilson ET al.
In 1971 as being like a paleontologist dream.
Just because it's such dense bone.
And it's not just bone. It has a lot of what we call
endo casts. And an endo cast is functionally
just where something has taken the surface of the inside of the
brain case. So it's not a brain, but it
looks like a brain and it takes the place of a brain.
So it's sort of a sand brain. And in the Reeves bone bed, can
you guess how many endocasts they have?
They've collected more actually since then, but just by 1971,
how many natural endocasts of oriodonts alone do you think
they found within 80 by 20? By three feet. 80 by 20 by
three. However, I have to consider that
they're oriodonts, so they die in herds and they're fucking
everywhere. These are not herd ones.
These are little tiny ones. These are little babies.
They were just delicious. Yeah.
Oh, OK. Well, OK, OK, so they're small,
so that means more of them could pack in per area.
I'm just gonna go. I'm gonna go with a 52. 157.
I was only off by 105. Now I will say that holy crap,
this study on basically like their shapes.
In 2009, he looked at 157 natural endo cast.
That represented a minimum of 107 individuals.
Because when we talk about endocasts, it's not always the
whole fake sand brain. Sometimes it's half of the fake
sand brain and you can't guarantee that other sections
didn't link up. That is still a minimum of 107
individuals. They're they're not still in the
cranium. They're not like some of them
are just loose brains. These are all loose brains.
Yeah, these are. Wasn't ready for that.
No. So that's the weird thing about
natural endo casts is natural endo casts are usually something
where you have an infill into the brain case, so the skull
gets filled with sand or dirt or something and then the skull
disappears somehow. Maybe it gets cracked and it
falls off and the brain is harder.
Maybe it, you know, dissolves because it's not made of sand,
it's made of calcium. So there's basically 107 loose
casts of the inside of a skull. Wow, wow.
I have, I just, I have. So I just have so many thoughts
like my one of my brains, my brain just went to the fact that
UT Austin used to have the largest collection of like human
brains, like just in jars, including of like Charles
Whitman and others. And so now I'm just like, and
actually one of the primates I'm going to talk about is got a
natural endocast and it's from West, TX.
So what the fuck is with Texas and brains?
Like I wouldn't put those two together.
Just kidding, just kidding. I love everyone from Texas.
Yeah, yeah, yeah, yeah. Texas is great.
Texas paleontology is definitely great.
So someone needs to go back to Reeves Bone Bed and actually
write up like a sedimental logical study.
The only other information I could find about Reeves Bone Bed
was like this mention of an abstract that was published in
1989 at a conference at GSA. And I haven't been able to get a
hold of the abstract. But the idea, from what I can
glean from a second hand source discussing an abstract, is that
maybe this was a predator den that was just eating a ton of
Orionuts. There was also other small
animals, Leptomerix, which is a really what is leptomerix?
Is that a paleomerisid? It's a weird thing that isn't an
Orionant, but they kind of look like I, I think it's actually
leptomerisid. I think they they're their own
thing. Oh my gosh, how dare you.
It's a weird little weird little ungulate.
A weird little artiodactyl. Yeah, in the you've seen,
they're all pretty. Weird.
And there's a ton of endocasts from them, too.
Yeah, so the oriadont that they found there is probably
bathogenies, which is a really tiny little oriadont.
There's a bunch of them at UT Austin that have little tiny
puncture marks in their skull. But again, someone needs to go
study that. I'm not 100% convinced by the
ambiguous mention of an abstract that thinks it's a carnivore den
because it's a little weird to have that many dead.
Or maybe it's a collector you know.
But regardless. And wouldn't they eat the
brains? Yes, well remember these aren't
brains, they are sand on the inside of a skull.
But the weird part is the skull is gone.
But they didn't bust it, right? The skull is gone.
But if the brains are largely intact, that tells me that at
least the sand had to be within the skull for a period of time
to get the shape right. So that wouldn't be during the
actual perimortem experience. That would be like taffanom.
Oh, right, which is here. We go, you know what, let's just
talk about the taffonomy. I wasn't sure if we were going
to fit this in, but it's kind of impossible not to, right?
So there are not as far as I can find a lot of studies on the
taffonomy of endocast. We find a lot of isolated ones.
So most of the papers about endo casts are like, we found a cool
endo cast, but with Orion's from this low occasion, it's we found
107. And the one study that I could
find, they were trying to figure out if they could actually
identify all of these oriadons as pathogenes revisai.
And they decided that no, probably it's not actually all
one species. They weren't sure if it might be
two different genera or not, but they only could conclude that
because they were variable enough to be too much variation
to be one species, they cannot link it 100% to this oriadon.
It's not 100% diagnostic for like a chunk of a like you can't
have a sand brain and identify exactly what it's coming from.
But I haven't found anybody who's really looked into what
are the consistent factors that are causing endo casts to form
because they're not very normal. They're not like a like a super
common aspect of sedimentology. They're they're normal enough
that most people who study paleontology know about them,
but they're not normal enough that having 107 endo, 157 endo
casts is like a normal collection.
That's pretty weird. So the endocast that I have
found people doing studies on, as far as Tafani goes, I found
one good study that did a study basically on a lynx endocast
from Italy. And what they found was they
took a look at the shape of the brain.
They realized that when it was initially deposited, the skull
was deposited probably in some sort of a river or a lake or
something. And it was deposited with the
foramen magnum, which is the hole where your head connects to
your neck, probably in the upward position.
And they, they realized this because it had stratigraphy
infills inside of it. So if you looked at the
endocast, because the skull was gone, yeah, you had really big
stones that had come in, well, big compared to a lynx's brain
that had come in and been deposited initially.
So like the bottom, the top of the skull, but the bottom of
when it was flipped over had bigger stones and then there was
another layer of like sand and another layer of silt.
So they had like slower accumulation of different sizes
of particles indicating that the water was slowing down overtime.
It was also probably multiple events, so it's not like one big
underwater landslide and then they looked at the outside.
I was going to say this sounds like you're describing a a bauma
sequence, you know, like that's exactly what you look for.
But those are turbidites. Those are underwater landslides
that you then are seeing the bigger grains at the base.
But Oh my God, that contained within a skull.
That's the most metal thing. That's like the most Geo paleo
you know. What it is though is I mean I
don't, I haven't found a they didn't say this, but I think
that might be a Geo pedal, right?
Like a way up structure indicating which direction is
up. Yes, which is funny.
Yeah. So bigger particles at the
bottom, they at least tell you which direction the endocast was
facing. And then on the outside of the
endocast itself is a layer of basically like carbonate
enriched like sediment. So essentially you had this
skull sitting upside down. It got filled with a couple
different events, so it was full of sand and rocks and things.
And then over time, the skull itself probably leached some
calcium into the outside of the little sand brain thing.
And yeah, all of a sudden, once the skull had decomposed or been
knocked off, there was enough calcium on this big lump of sand
in the shape of a brain that it stuck around preferentially.
So wow, yes. Oh, paleontology is so cool,
yes. God, and for some reason in the
Reeves bone bed, those brains are really preferentially
preserved. I wonder if bathogenes, unlike a
lot of other oriadonts, has a really thin skull.
So it it's it's other oriadonts are like bowling balls with
their head. So I wonder if Bathogenes
bathogenes. I wonder if it was just a little
bit too fragile and so they don't stick around.
But we have a lot of endo casts of pathogenes.
Even though I think the story of the taphonomy is maybe the
cooler aspect, it's definitely not what people love to study
about endo casts. And in fact, natural endo casts
aren't even the entirety of the story that we're going to talk
about today. So a natural endo cast is where
the the sand and whatever infills the skull and then
somehow gets separated from the skull, at least partially.
But you can of course, simulate this.
You can put mold compound into a skull and then break it open.
And you can have like a, a replica of how the brain was
imprinting against the skull. You can also do CT scanning, you
know, if you don't want to break the skull that you're dealing
with. So studying endo cast has become
a kind of, it's become a lot more popular for sure, because
we don't have to just wait until we can find sand, sand brain
casts. We can actually make them
ourselves. So tell us about people who make
them. Yeah, and I love the CT scan
aspect. I did a little of this actually.
And what my question is immediately is with the bath
Jennies, has anyone taken a CT scan of an empty, like a, you
know, a full skull that doesn't have an endocast and then
compared it to one of these loose brains to see if there's a
general fit? Like 'cause you said there's no
for sure ID but that also cost money.
They did that. That was what this paper from
2009 was, was they compared it very, it was actually a very
good paper. I say actually cause a lot of
worry, not papers sadly or not, but it was a very good paper.
Megan is picky. Also very picky, but yeah, they
they they took ACT scan of bathogennis and they cross
compared it to a bunch of the brains.
But they also, I think discovered that a when you have
a sandy endocast, sometimes it gets rattled around.
So sometimes the features are kind of worn off and then just
it it isn't super clear. At least at that point, there's
enough variation that telling the difference between bath and
Jenny's and Liam Needy's another small Orion that was alive at
the time that we just don't have a good enough concept of their
brain slash. Maybe their brain isn't
diagnostically different. Sometimes you can't idea brain.
Science. Wow.
That's, that's that's very, very cool.
And again, just like West, TX. Thank you.
Very, very cool place. So, yeah.
But where would we be today without some pivotal research
from the founding paleontologist who created the entire field of
paleo neurology, the study of fossil brains?
And that was Tilly Edinger. Doctor Tilly Edinger, I should
say. And her full name is Doctor
Johanna Gabrielle Altilly and she went by Tilly.
So thanks girl, appreciate that. It makes my life a little bit
easier today. And she was inspired, you know,
talking about natural endocast, right?
So those can form in anything that's hollow.
You know, we can find endocast and, and other things in it.
It usually means brains, but sometimes it can mean like inner
ear structures that we might talk about later.
It can also be like nasal features, like your nasal
turbinates, little swirls in your nose.
So it really just is like this perfect kind of, yeah,
sedimental, logical replica of this hollow void.
And that is how Tilly first got exposed to the fossil brains.
And I will say for the record, she was born in the late 1800s
and she is the daughter of a very famous neurologist.
So I will say for the record that she is a total nepo.
Baby, you had to be at that point to be a woman in science
though, so. Exactly.
Oh my God, that's exactly what I was going to say is like, but so
the fact that this woman pursued APHD in 1920, it goes to say
like, holy shit. Maybe she did have an upper hand
because of her lifestyle and her father's connections, but it
this is like a time that there was no such thing as female
neppo babies. So just no, sorry, that's not an
option. Yeah.
So she actually did her PhD in Frankfurt, Germany, where she
was from. And she was working on, she was
just doing straight up paleontology for her doctoral
research. And she was working on this
Mesozoic marine reptile called Nosaurus, and it had a skull
with a a natural brain cast in it.
And she could see, I think part of it was partially exposed,
which are the most metal looking ones.
When you can see them, they're still in the skull, but like
only a chunk of the skull is removed and you can just see
these brains behind it, which is really exciting.
So she got super into this because she was like, oh shit.
You know, Like I can apply what I know from growing up with a
total nerd for a dad and be able to look at the external features
of brains and fossil animals and be able to say more about the
evolution of brains and be able to have that deep time
perspective. Now, unfortunately, her and her
family were Jewish and they lived in Germany in the 1930s
and 40s. Not a great time to be Jewish in
Germany. She really didn't want to leave
Germany. It was her home.
She did lose immediate family members to the Holocaust.
And it was actually paleontology that got her out of Germany.
She has a quote where she was literally saying, like, one way
or another, fossils are going to be how I escape.
And it was that Roamer, the famous Roamer of paleontology,
the Roamer session, he gave her a unpaid research position at
the Harvard Museum of Comparative Anatomy or whatever
it's called. And that is how she was able to
get a visa to get to the United States in 1940.
So she was able to escape. Another interesting fact about
Tilly is that she was deaf, not her entire life, but she started
to go deaf from this degenerative disease of starting
in like high school. And so by the, you know, by the
time she'd gotten her PhD, she was pretty much fully deaf.
And it unfortunately seems like it led to her untimely passing
because she was hit by a truck, unfortunately, and did not did
not hear it coming. So there are lots of quotes
about how it was. Yeah, the very She just had a
tough, tough situation. You could be born to a doctor
and still have a tough life, y'all.
But she was like, OK, so I can see in this marine reptile that
it has a natural endocast. I wonder what happens if I fill
it with rubber or plaster or later plastic and then either
gently pull it out. And by that we mean break part
of the skull usually to get whatever your medium is out and
then be able to study those features.
So she's looking at things for all of these internal
structures, looking at things like, OK, one of the first
things that she studied was again, whales.
Sorry everyone, whales again. So we know that, you know, parts
of your brain have a lot to do with different senses.
So for example, your nose smelling is your olfactory
bulbs. So those are all having to do
with sense of smell. I think they're generally
towards the more anterior portion of the brain.
And so she could see that in fossil whales, they got smaller
over time, largely because they don't need to smell as much
underwater. They might need things that are
more of like the hearing and aspects that are being selected
for. And so then she really dove into
other animals too. She wrote an entire book.
I've got it right here on the evolution of fossil horse
brains. She looks at 55,000,000 years of
horse brain evolution. And her conclusion was, I want
to see. If they're not as good as Artie
Anactyls, is that her conclusion?
Yeah, very much so. And that they had weird penises.
No, she didn't know that part. No endo cast of those,
fortunately for all of us. I, I don't know why I laughed so
hard at this line, but but I did, she wrote.
While the Equidae developed from cat size to horse stature, the
brain became progressively smaller part of the body.
And I was like, I was like, I don't know why I'm like talking
shit on horses, but I found that really, really amusing and OK.
And before Tilly, you know, before literally trying to
interpret fossil brains, scientists were trying to
understand like the evolution of brains by just like dissecting
modern animals and kind of doing like comparative methods.
So it was more of like, oh, I dissected this fish and its
brain is like this. And so compared to them, like a
reptile and a mammal like, which is, you know, informative, but
the things diverge. Things evolve on their own
lineages. So it it's hard to say the
ancestral condition by looking at all modern things.
So she was really, really good at being able to figure out the
evolution of brains by the skill set of smashing skulls and
taking names. It's pretty pretty badass.
One of my favorite things I read about.
And then found copious amounts of evidence for that.
I was like, I don't know if you were super familiar with her
work and I don't know if you were a fan of hers prior to
this, but you're going to be. You're going to be.
So I was reading this other book I have about Tilly that's mostly
in German. Whoops, my bad.
There are a few sections that are in English.
This is the quote. To appreciate her kindness to
me, one should keep in mind her deep hatred for Marsh.
Yeah, OK. Which I never fully understood,
but in many publications she took great pains to expose what
she considered to be fraudulence of Marsh's science.
She was convinced that he invented the images of bird
brains from Hesper Ornis and Ichthyornis that he had
published, that she literally like he made them up and that he
had never actually prepared the specimens the way she does.
And then I guess this guy, this, so this is Harry, Harry Jarrison
who wrote this, who said that they they were like gossiping
like little girls talking mad shit on Marsh.
And one of his points is that Carifidon, which is another ES
scene, big awkward ungulity thing, a lot of them in Texas as
well, that he created, like these fantastic pictures of the
brain of Carifidon and the enlarged olfactory bulbs in a
Uinta Fear, Like they're gossiping about how dumb he is
because he made a Uinta fear brain look like an enlarged
rodent brain. Like this was her sassafras.
Such specific, specific gossip. They point out that you can fuck
it up when you're doing these human made casts that
essentially you might be removing they say essentially
matrix from the cranial cavity, but it's actually bone and you
might not be able to know the difference as you're prepping
through it. And so then you can come up with
inaccurate relative sizes of the portions of the brain, which is
just funny. And so then I was like reading
her book The Evolution of the Horse Brain, and I didn't have
to read very far before she just starts talking match shit on.
Marsh was totally here for it and one of her lines and like
this is one of those. I'm going to read it and then
explain why I think it's really funny.
If I can get through it, it's it's like because it's academic
sass. I'm just going to say in advance
that it is like her being like, fuck you, you're an idiot.
But she's doing it academically. So she wrote one Paleo
neurological theory of evolution must be briefly discussed.
Although the outcome of a typical 19th century ideology,
it has found its way into so many kinds of literature that to
test it with the evidence of our study seemed necessary.
Essentially being like, this is a ton of bullshit.
We all know it's bullshit, but people keep talking about it as
if it's legitimate. So here I go again, showing you
why this is total horseshit, no pun intended.
Because it's all about horses. Just like I love her.
And then she like, literally spends multiple pages talking
about why Marsh was wrong. And the main thing that she
criticizes is that Marsh had this theory that as animals
evolved, their brains always got bigger, especially in mammals,
that the derived mammalians are so superior, which, you know,
probably not talk to a, you know, crocodile that.
And a lot of her work, as we're talking about with the horses is
that they actually get smaller proportionally to body size,
especially, she writes, once they evolved the muzzle and the
Miocene, the brain becomes an even smaller portion of the
head. And it has remained that way in
the modern day. And so she is just totally
reading him for just being over generalization and being too
focused on function instead of the constraints of ancestry is
really her whole point, which is why Stephen Jay Gould loved her
like a lot too. So it's just kind of this idea,
and I think that that goes into what you're going to be telling
me about, about the size of brains and brain regions.
Yes. Why?
What we think we know might be what we actually don't know,
Yes. Yeah, yeah.
So there is this concept that is often referred to in the study
of endo casts, whether they're sand or otherwise, called the
principle of proper mass, which is basically this idea that the
size of a region of the brain is proportional to its ability to
process information. So that means that like if you
have really great vision, you'll probably have a bigger section
of your brain that is dedicated to vision.
And of course, therefore that would mean that if you could
look at the brain, or at least look at a cast of it, you might
be able to determine where basically a animal was investing
its brain energy. Is it really big into sight?
Is it really big into smell? Is it really big into balance?
And as I was reading through these papers, I did notice that
Tilly Edinger's concept of hey, yeah, your phylogenetic
relationship there is going to really kind of determine.
A lot of that stuff is absolutely true.
When you talk about brains, you really have to keep in mind who
they're related to. So for example, the endocasts of
dinosaurs way different than the endo casts of birds and mammals.
So with birds and mammals, our brains fill that space.
They push up. I like I already love this.
I know really, I've been taking this is this is week two of
volunteering to talk about dinosaurs.
And it's just week two of Megan finds a reason to talk shit
about dinosaurs because. Yeah, so our brains are pretty
big and they press up up against the confines of our our skull.
So you can actually do a lot more interpretation of a bird
brain or of a mammal brain than you can of a dinosaur brain,
because dinosaurs, by and large, I'd.
Never thought about it like that.
Yeah, so dinosaurs, not all of them Pachycephalosaurs, I
imagine just because they don't have a lot of brain space left.
They have pretty tightly constrained brain.
So you you can tell more from their endo casts.
I mean, they've dedicated so much of their skull to bone.
So like they just don't have a lot of space for that brain.
Is my is my thought. That's right.
We got to get that Dome. Yeah, so not all animals fill
their entire brain case. Celicants and basking sharks,
Less than 1% of their brain space is full of brain.
Nobody told me what the rest of it was by the way, So I've just
been envisioning very tiny little brains floating around a
fluid. I'm sure that's not really true,
but the most of the brain case in a coelacanth or a basking
shark isn't brain. It's actually the same with
alligators. And I, I, I giggled a little bit
when you said something about ask a crocodile.
Because it turns out that with crocodilians, if you want to
talk to a big brained crocodilian, you should talk to
babies. Because baby crocodilians have a
much bigger brain size in comparison to their body than
adults do. Because adults might grow their
big fat faces, but they don't actually grow their brains as
quickly. So baby alligator has about 68%
of its brain capacity full of actual brains.
So like the actual organ is only like 68% of that space, whereas
adults are like 32%. So a real sharp decline.
Yeah. So that means a lot of things
other than just kind of the funny implications of having
less brain as you get older. But it also means that because
there's not as much brain inside the brain case, that it's not
pushing up against every single boundary of the skull.
So you're not actually getting. Like with mammals, you can look
and you can see the wrinkles, You can see the different
regions of the brain. You can see veins even that are
pushing up against the surface. But with alligators you can see
like the different general regions and in some dinosaurs
you can see a little bit more, but there's not nearly as much
detail preserved with an endo cast because the actual it's a
smooth brain as far as the inside of the skull goes because
there's no brain touching it to make brain shape.
There's no. There's no mold.
There's no, there's no Wakadu designs to to replicate on the
surface of of the brains because they're not filling it.
And for whatever reason that hasn't been selected for, to
decrease that space or use it for something else, right.
I mean, like, that's weird, but like, like, is that just?
Yeah, I guess that works. I'm sure there's something else
in there, you know, there this is not probably just an empty
space with a brain floating around in it.
But I I genuinely could not find in the space between this
morning when I realized that fact and this afternoon when we
were filming this. I couldn't figure out what else
was in there. So fill it in with your mental
image of whatever else you might imagine is in a dinosaur brain
or an alligator brain. Confetti.
Yeah.
Oh my God. Like candy.
Candy like. Yeah, I did read a paper about
someone found an isolated hadrosaur endo cast with a
little bit of skull attached to it.
They found it floating in a tide pool, well, not floating, but
rolling around in a side pool. And when they looked at the
actual endo cast, it was filled not just with sand, but it was
also filled with it had fossil leaves, fossil wood, and some
bone that wasn't its bone like some other bone that had gotten
shoved into the brain. So like, that's as complex as
that Hadrosaurus brain ever. Got yes, SO11 fun side effect of
all of this is essentially that when you're talking about endo
cast, you do have to to be aware of like just size alone is not
actually going to necessarily correspond to changes in
intelligence. But also with certain groups of
lineages, you have to take into account the body size, and you
have to take into account whether it's an adult.
And someone use that to talk shit about Nanotyrannus.
Yes, Oh my God we're talking about Nano Tyrannis on our
podcast. I never thought we would sell
out. We are total sluts.
Geez. So nano tyrannis, if you're not
familiar, is a controversial dinosaur.
Some people think it's a juvenile tyrannosaur and not a
new species, other people think it's a new species.
I don't care, but this particular paper said.
Right answer. They, they took cast of these
different dinosaurs brains. I think they did CT scanning.
So they had to do all of this like complicated stuff because
remember, the endo cast of a dinosaur is its brain plus
whatever mystery goo is outside of that.
So they did some weird math where they compared endo cast
versus actual brains of alligators use that mathematical
relationship to scale the endocasts of these theropods.
And so the the big Nanotyrannus disc was that they looked at
Nanotyrannus and they found that it had too much brain compared
to its body size, which means like alligators, they thought it
was a baby. A juvenile a juvenile.
Oh, I I see. I like that kind of comparison
of like it has a larger ratio of brain to body size.
Okay, okay, unique. I mean everyone's digging for
every freaking angle they can get with the nano stuff.
So here for it. Here for the new new
perspective. And one chunk of the brain that
seems to pop up a lot and be relatively visible regardless of
how little your brain touches your skull is probably the one
of the stupider words that I had to read.
I have a note here that says that this entire paper reads
like fucking Doctor Seuss poetry.
Because. Here are some sentences.
I highlighted the protrusion of the flocculus into the fossa,
the volume of the nodulus and uvula.
Just Oh my God. Yeah, so the flocculus is one
part of the brain. Tell me.
About this flocculus. Yes, the the flocculus, which is
a word that, if I'm not directly staring at it, removes itself
from my brain. I don't remember this word every
time I've scrolled away from this page.
Probably because. You don't have a flocculus.
Flocculus is gone. So flocculus basically it
operates the eyes, neck and head movements.
So you being spatially aware of where your head is and what it's
doing, pretty important function, although apparently
not in sauropods. So the volume of the flocculus
has been analyzed to see if like basically like how big is your
flocculus relates to, you know, how good your eyes, neck and
head movement is. Even though the term flocculus
is fucking hilarious to me, I did find it a little confusing
while reading today. And so for all of you who study
the flocculus, please keep this in mind.
There is a difference between the flocculus and the floccular
fossa. So the flocculus is the stupid
part of the brain that deals with where the fuck your your
head is. Yeah.
And then the floccular fossa is the divot inside of the skull.
So the floccular fossa is the only thing you're measuring if
you're measuring an endo cast, and that is not the full
flocculus. So even though there are some
papers looking at flocculus size saying like, OK, well if you
have a big one, it probably means you're like a carnivore
because you need better understanding of where your head
is. Whereas if you were an
herbivore, you can just smack your head into leaves, I guess.
But the floccular fossa that you're measuring in a dinosaur
skull is not the same as the actual flocculus.
In particular, we know with birds at least, their flocculus
is actually made-up of two different parts, and one part is
on the inside of the brain. So like, you can't 100% cross
correlate these two things. That makes sense, yeah.
But I guess you work with what you've got too.
You know, I can't. I can't.
It can be hard to to clock it when it's like, yeah, no, it's
not perfect. And like, if, you know, you're
working with what scant material we have, and then I have to just
take it back to what you're talking about.
You're like 157 Orient brains rolling around.
All over the place. And the individual variation
playing enough of a role that it's hard to even make a direct
fit. And so then when we're talking
about like literally maybe one or two Nanotyrana skulls out
there and trying to make all these larger, you know,
interpretations of it, I just have to like, I feel like that's
always my thing with dinosaur people as I'm like time the fuck
out. Your sample size is one like you
cannot account for variation in that.
Please give me a bigger sample size.
And I know that sometimes, again, it's not possible.
And then maybe just hedge on, let's not create an entire new
genus and tell like we have a little bit more evidence.
But you know what was me? Don't listen to the idiot mammal
paleontologist up in here. So.
Yeah. So the flocculus is a is a
little bit weird apparently also the parts of our brain that
control like I guess our flocculus that control like our
ability to keep smooth pursuits of tracking a moving object in a
field of view. If you get a brain lesion on
those parts, your brain can compensate because we have brain
plasticity. So even though these regions are
like broadly corresponding to these sections, it's not 100%
guarantee that the animal hasn't adapted a different kind of
method for dealing with that stuff, which is.
Interesting. Yeah.
Oh, and I've seen, you know, I've seen a lot of actual full
blown models of dinosaur endocasts and things like that,
which when you look at like a mammalian one, they do look
pretty brainy. They look like brains.
When you see one of a dinosaur, it just looks like, I don't
know, an Ant hill, like the internal structure of an
anthill. I don't know, it's just like.
It. Looks like a weird root system
or something like a carrot gone horribly wrong.
I don't know, but they don't look like brains.
They just look like essentially cranial nerves that have never
actually turned into brain. They're just like nerve brains.
I don't know. We're just like kind of smooth
lumps because they're not pushing up against the skull
like it's a really good. Yeah.
So that's. A really good point.
When we yeah, so when we talk about these brain structures,
these brain structures can change one of the and this is
the other stupid, stupid word, the wolst.
I even looked it up on YouTube because I was like, how do
people pronounce this? YouTube doesn't have a
pronunciation option. I've never found a word on
YouTube that doesn't have a pronunciation option.
But the wolst is a portion of a bird brain and it's, it's
supposed to maybe like be connected to like your, your
locomotion ability. And so they've studied it in
things like Penguins because Penguins have really big wolsts.
So whatever the wolst is doing for them, it should in theory.
And they've also found that like other aquatic animals often have
very big wolsts, but they show up after Penguins go into the
water. So like very very ancient
Penguins don't have wolst so and it shows up like 25,000,000
years later is when they get a wolst.
So like, even though these structures might seem odd in
something like a Penguin, they often are showing up at
different times and that might be related to brain plasticity.
But they're like making it work. I honestly think it's evolution
being like, I know that you're humiliated and your inability to
fly, so here's a wolst consolation prize.
Don't know what it does, but here you go.
Yeah, that's dinosaur brains. Dinosaur brains are smooth
brained. They float around somehow in
their skulls. Sometimes they bump up against
the surface, sometimes they don't.
Babies have bigger brains. Nano Tyrannous had a big brain.
That's dinosaur brains. So I'll get there.
I love this idea that like, you know, it's like this kind of
insult, right? Is to be like, oh, you've got
nothing in your noggin. Like you can hear like a marble
rolling around. And to know that now that is
like actually supported with concrete evidence about
dinosaurs. It just continues to feed my
superiority over the most. Whatever.
I appreciate them, but they're totally overrated.
So ha ha ha ha ha ha ha. Motherfuckers.
You know, I was actually thinking a nice and could be you
were just talking about this behavior and understanding like
things of just like eyesight and actually the semicircular canals
and cochlear like the features of the inner ear.
I'm going to chat about that for maybe our finale.
And so in your inner ear, you've got some funky shit.
I know because my son just had his first ear infection.
And so we got to look at that poster in the pediatrician's
office of the inner ear and what it looks like when it's like
pussy and infected, which is what Tracy's ear was looking
like. It was literally like oozing out
of, it was gross. It was very gross.
However, like I've done some CT work at UT Austin.
I did a bunch of brain endocast, but I also did some ears.
And you've got these semicircular canals which are
like a series of about like 3 loops that are a big part of how
we help with things like balance and that are literally keeping
that sense of balance. So there have been research into
especially like mammals. And primates is that there seems
to be a selection for having this large.
There seems to be quite. A large canals.
Huh. Yeah, larger canals.
I think I I came across some similar stuff with pterosaurs in
particular. Is this preponderance towards
bigger bigger canals? Were you finding variation?
Was that there? Seems to.
Also be like variation that has to do with literally the
curvature of Mammalias and that seems to be that organisms that
have large eyes and acute vision have oh God, is it bigger or
smaller? That's what I don't have a link
for right here, but essentially right.
Being able to interpret an aspect of eye size, which then
can also go into like hunting and just overall placement in
your ecosystem. What can be learned from
literally looking at that? And what's also cool is that
this paper found that having small semicircular canals tends
to be a thing that we find in fossorial mammals and
plesiodapiforms, which are things that Burrow.
So there seems to be the selection for getting those a
little bit smaller for whatever reason.
Is it a balanced thing? Is it an A reliance on other
senses and a less reliance on those senses?
But we can interpret some aspects of locomotion senses.
Again, these are forms of behavior by looking at the inner
ear. And then also the cochlear is
the part that looks like a little snail.
It's like curvy and windy and it all has to do a lot with
hearing. So again, we can look at the
size of that spiral shaped inner ear and get a vibe for at least
you know, again, this is not one, one to one.
But you are going to have a better idea about that adaptive
ability by looking at the size and like how tight the circles
of the the snail shell is, which you don't actually have a snail
shell in your ear, but it looks exactly it looks exactly like
that. OK, yeah, let me just treat this
abstract as the semicircular canals of the inner ear detect
head rotations and have to have compensory movement to stabilize
the gaze and help maintain visual fixation.
So it's very interesting that eyes are having something to do
with your ears that you would think like, no, those are
separate senses, but they cannot, well, they're all
friggin related. They're all in your own head.
So it's just really cool to think that it's, it's not just
brains that endo cast can be really useful for.
It's also these other hollow places in your body.
If it's hollow, we can endo cast it, which is which is exciting
to think about. So yeah, I've had some
experience with all of my experiences have been with the
with the some parts of the skull.
So I'd be curious to know about, I don't know if you like, is
there soft tissue of like, I was like Googling like intestines,
like do we have like endo cast of intestines and things like
that? And I'm also realizing that we
were just talking to Doctor Ohenia Gold last week, and she
works on bird brains, so maybe we'll have to do a bonus thing
and chat with her or something like that too to find out more.
Well, at least have to ask her what the hell is inside of a
dinosaur brain? If it's not brain, what is it?
Float again, great question. Thank you for listening.
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Thanks for listening. We'll tell you all about an
insane brain bonanza in West, TX and stumble through medical
terms for tissues that don't usually flossulize.
God damn it. That was perfect.