OK, let's let's unpack this. Welcome to today's
deep dive. I'm your host. And sitting across
from me is our resident paleontology expert.
Hello. Glad to be here for this one. Yeah, I
am, too, because usually, you know, when we talk
about dinosaurs, we are talking about. The absolute
superstars. Oh, absolutely. The heavy hitters.
Right. The T -Rex, the Triceratops, Stegosaurus,
the ones that end up on lunchboxes, pajama sets,
and billion -dollar movie franchises. They have
very clear brands. Exactly. You know exactly
what you're getting. But today, we are doing
something a little different. We certainly are.
We are leaving those superstars completely behind.
Yeah, we're looking at a dinosaur that is...
Less of a movie star and more of a, well, I guess
you could call it a cold case file. A cold case
file. I like that. It's a detective story that's
been running for over a century now. That is
a very apt way to put it, honestly. It's a story
about... A fossil with a massive identity crisis.
A dinosaur so confused about its own identity
that its current scientific name is literally
written inside quotation marks, like ironic air
quotes on an official government form. Right.
And those quotation marks are actually quite
important here. They aren't just there for emphasis.
No. No, they signal that we know the name is
wrong. We just don't have a better one for it
yet. That is wild to me. So today we are doing
a deep dive into the creature known. provisionally
as Dryosaurus Grandus. Dryosaurus Grandus. Even
saying it out loud sounds a bit tentative. It
is tentative. And honestly, this isn't just a
story about a lizard from the Cretaceous period.
It's really a story about us. How so? It's about
how we categorize the natural world, how we make
mistakes, and how science is basically a century
-long argument over, well, a handful of broken
bones. I love that. I really do. So let's set
the scene for the listener before we get into
the crazy beer. bureaucracy of it all. Where
are we and when are we? Okay, so we are in the
early Cretaceous period, which is roughly 112
million years ago. Okay, got it. And geographically,
we are standing in what is now known as the Arundel
Formation in Maryland, USA. Maryland? See, okay,
I grew up thinking all dinosaurs came from out
west. Most people do. You know, Montana, Utah,
the Badlands. Maryland is not exactly the first
place you picture when you think of a Jurassic
Park scenario. True. The American West usually
gets all the glory. Formations like Hell Creek,
because the preservation conditions out there
were just perfect for whole skeletons. Right,
the classic complete skeletons you see in museums.
Exactly. But the East Coast has a very deep fossil
record, too. The problem is, it's much more fragmented.
Why is that? Because it was wetter. It was swampier
back then. Things washed away or degraded. So
we aren't finding those pristine skeletons laid
out nicely in the rock. No, definitely not. We
are finding bits and pieces, foot elements, isolated
teeth, maybe a vertebra here or there. And that
scarcity of material is really the villain of
our story today, isn't it? It absolutely is.
Because the mission for this deep dive is to
basically trace how a couple of foot bones found
in that Maryland mud managed to confuse paleontologists
for over 100 years. Exactly. We're going to look
at the meshe, highly bureaucratic, and frankly
fascinating world of dinosaur taxonomy. Taxonomy,
which is the science of naming and classifying
things. Right. I have to say, looking at the
research notes you sent over for this, I was
actually laughing out loud. It gets a bit ridiculous.
It really does. It feels like every time a scientist
looked at these bones, they just gave it a completely
different name. Pretty much. It's like the dinosaur
entered a witness protection program every 20
years. It does feel that way. But it really highlights
that science isn't about static, unchangeable
facts. Right. It's an ongoing process of revision.
As we learn more about the world, we have to
constantly update the labels we put on it. So
let's start at the very beginning, the origin
story. What exactly did they pull out of the
ground in Maryland? Well, you need to lower your
expectations right now. Okay, expectations lowered.
Do not picture a grand museum rotunda display.
We are dealing strictly with what are called
foot elements. Foot elements. That sounds like
a polite euphemism. It is. A little bit. Specifically,
we are talking about a phalanx. A toe bone. Yes.
A single toe bone. Yeah. And an estrogalus, which
is a major ankle bone. Okay. And that's it. That
is the entirety of the evidence for a very long
time. Wow. That is not a lot to go on. No, it's
not. I mean, imagine finding a hubcap on the
side of the highway and trying to describe the
entire car, including the make, the model, and
the year it was built. That is a perfect analogy.
And that extreme scarcity of evidence is exactly
why we have this century of confusion. The whole
story starts back in 1888. 1888. So we're talking
about the early, early days of American paleontology,
sort of the Wild West era of dinosaur hunting.
Right. And the famous paleontologist O .C. Marsh
gets his hands on these specific bones. Okay.
Now, Marsh was a titan in the field. He was heavily
involved in the famous bone wars. But he was
working with very limited comparative material
back then. Right. They didn't have databases
of thousands of skeletons to look at. Exactly.
So he looks at these foot bones and he has to
make a call. He assigns them to Allosaurus medius.
Wait, hold on. Allosaurus? Yes. As in? The giant
meat eating top of the food chain predator. The
very same. So he looks at a single toe and an
ankle and says, yep, this is a killer. This is
a massive monster. He did. But to be fair to
Marsh, Allosaurus was what we call a wastebasket
taxon back in those days. A wastebasket taxon.
I love that term. What does that mean? It's exactly
what it sounds like. If you found a fossil that
looked vaguely like a big meat eater. And you
weren't quite sure what it was. You just tossed
it in the allosaurus bin. Exactly. You threw
it in the allosaurus wastebasket until proven
otherwise. Marsh saw a theropod, a beast -footed
dinosaur, and went with the default option. So
for decades, the accepted scientific consensus
was that there was a massive allosaurus stalking
around the swamps of Maryland. Correct. That
was the story until 1911. Enter Richard Swan
Lull. Richard Swan Lull. He was a very thorough,
very careful researcher. And he is doing a comprehensive,
systematic review of all the fossils from Maryland.
He takes a much closer look at these quote -unquote
allosaurus bones and decides, no, this doesn't
fit at all. What does he see that Marsh missed?
He sees something structurally different enough
to erect an entirely new species, and he calls
it Dryosaurus grandus. Okay, here's where it
gets really interesting to me. I did a quick
search on Dryosaurus before we started recording
today. And what did you find? Dryosaurus is not
a scary apex predator. Not at all. It's a plant
eater. It's a relatively small bipedal herbivore.
Precisely. It's an ornithopod. So within roughly
20 years, this animal went from being a terrifying
allosaurus, a major predator, to a dryosaurus,
which is essentially a relatively harmless vegetarian
gazelle thing. Yeah. That is a massive shift
in perspective. It is huge. It completely changes
the ecosystem you're imagining in your head.
Instead of a heavy hunter stalking the Maryland
swamps, you have a light runner, a browser. That's
a completely different animal. It is. Lowell
was looking at the morphology. the specific shape
of the bones. He was seeing similarities to the
bird -footed plant eaters. He thought the ankle
looked like it was built for fleeing, not for
fighting. Okay, so problem solved, right? It's
a dryosaurus. Case closed. Let's print the new
textbooks. Oh, not even close. We are just getting
started here. Really? Yes, because this is where
we hit the great naming collision of 1920. 1920.
This is where C .W. Gilmore comes into the picture.
Yes. Charles Whitney Gilmore. He was a curator
at the Smithsonian. Very meticulous guy. Naturally.
He reexamines the bones yet again. And he strongly
disagrees with Lowell. Of course he does. Why
would anyone agree with anyone else in this story?
Gilmore decides that this animal isn't a dryosaurus,
so not a herbivore. And it's not an allosaurus,
so not a big carnivore. So what's left? He thinks
it belongs to the genus Ornithomimus. Ornithomimus.
Let's see, ornitho means bird, so that means
bird mimic, right? Correct. These are the ostrich
dinosaurs. Ostrich dinosaurs. Picture an ostrich,
strip off the feathers, or maybe keep them, they
likely actually had feathers, add a long tail
to it for balance, and give it arms with sharp
claws instead of wings. So structurally, they
are theropods, the same broad group as a T. rex.
But they behave and look more like giant, weird
ground birds. Exactly. Long legs, fast runners,
likely omnivores or herbivores, depending on
the species. Okay. Gilmore looks at those foot
bones from Maryland and sees clear parallels
with these ostrich mimics. So logically, he wants
to move our Maryland friend into the Ornithomimus
family. Okay, so he wants to call it Ornithomimus
grandus. He takes the species name Lul gave it,
grandus, and attaches it to his new genus. Or
Nethomimus grandus. That sounds dignified. It
does sound dignified. It sounds authoritative.
But there was a massive bureaucratic nightmare
waiting for him. Ah, the rules of nomenclature.
The International Code of Zoological Nomenclature,
to be precise. Right. In taxonomy, you simply
cannot have two different species with the exact
same name. Which makes sense. It's a hard rule
to prevent absolute chaos. And it turns out our
old friend O .C. Marsh, the guy who first called
it an allosaurus back in 1888, had named a completely
different fossil. Ornithomimus grandus back in
1890. Oh, wow. So the name was quite literally
taken. It was preoccupied in scientific terms.
Marsh beat them to the punch by 30 years with
a specimen he found out in Montana. Right. So
even though Gilmore was entirely sure this Maryland
dinosaur wasn't Ornithomimus, he was legally
scientifically forbidden from calling it Ornithomimus
grandus. It's like trying to register a username
on a website and getting the error message that
says this user ID is already taken. Try again.
That is a perfect analogy. User Ornithomimus
underscore Grandus is already active. So what
did he do? Well, Gilmore had to come up with
Patch. A quick fix. He renamed Lull's Maryland
Dinosaur to Ornithomimus Affinis. Affinis. Which
basically just means related to or akin to, right?
Yes. It was a workaround. It's basically him
saying, this is the Ornithomimus that is related
to the other ones. But... And here's the irony.
And this is the twist that really makes you shake
your head at this whole academic process. I know
exactly where you're going with this. I love
this part. Tell the listener about those original
bones from Montana. So Marsha's original Ornithomimus
grandus, the one from Montana that blocked Gilmore
from using the name. Yeah. The primary holotype
specimen. Yeah. It is presumed lost. It's just
gone. Completely vanished. No one knows where
it is today. It might have been misplaced in
a museum move or it crumbled to dust or it was
just lost in the shuffle of 19th century cataloging.
So let me get this straight. Gilmore had to completely
change the name of the Maryland dinosaur to avoid
a conflict with a bone that basically doesn't
even exist anymore. Technically, yes. Marsha's
Grandus is a ghost. It's a phantom fossil. But
the rules are the rules. Because the name was
published in a recognized journal back in 1890.
It held the trademark, so to speak. That is wildly
frustrating. It's paperwork over actual paleontology.
We are literally letting a ghost dictate the
science. Welcome to the academic world. But don't
worry, it didn't stop there. Gilmore's rename
to Ornithomimus Affinis was just a pit stop.
Right, because now we move into what you called
the mid -century identity crisis. 1922, just
two years later. Matthew and Brown. Two other
major heavy hitters in the field of paleontology.
Okay. They looked at the Maryland dinosaur and
assigned it to yet another genus entirely. Cholosaurus.
Cholosaurus. I actually haven't heard that name
much. It's really not commonly used today, but
they called it Cholosaurus affinis. They kept
Gilmore's specific species name affinis, but
they changed the genus again. Why? They thought
it was more closely related to this other group
of hollow bone dinosaurs that were being found
in New Jersey around that time. It honestly seems
like everyone who walked past that specific drawer
in the museum just felt the uncontrollable urge
to slap a new sticky note on it. Like, I think
it's a colosaurus. No, I think it's an ornithomimus.
It does seem that way. But you have to remember,
they were trying to make sense of incredibly
limited data. Just a toe and an ankle. Right.
They were comparing a toe and an ankle to whatever
brand new discoveries were coming out of the
ground that exact year. It was a moving target.
But then in 1972, the comparison went global.
And this is the part of the story that feels
like a massive stretch to me. Yes. This is Dale
Russell's review. Russell was a Canadian paleontologist.
Brilliant guy. Okay. He was systematically reviewing
North American ornithomimosaurs, and he looked
at our strange little Maryland foot bones. And
he saw something highly specific. He did. He
noticed the petal unwiles. Which means the toe
claws. Right. He noticed that the toe claws were
curved. Now, usually... Ornithomimosaurs, the
ostrich mimics, have fairly straight, flat claws.
Because they run on flat ground. Exactly, like
an ostrich. But these Maryland claws were distinctly
curved. And he thought, wait a minute, I've seen
this exact curve before. In Asia? Correct. He
thought they looked exactly like Archaeornithomimus,
which is a dinosaur found all the way over in
China. That is such a massive leap. It is a very
bold claim. Yeah. Biogeographically, it's fascinating
because it implies... a major physical connection
between the continents, potentially a land bridge,
allowing these animals to migrate back and forth
across the globe. Wow. So Russell renamed it
again. Now it officially became Archaeornithomimus
affinis. Archaeornithomimus affinis. That is
a real mouthful. It is. But it fundamentally
linked our mysterious Maryland fossil to a specific
distinct lineage of Asian dinosaurs. So surely
that finally settled it. It's an Asian immigrant.
Mystery solved. Let's go home. You would think
so. But science is a pendulum. It swings wildly
towards these bold, grand theories, and then
eventually it swings right back towards extreme
caution. Which brings us to the 1990s, and the
skeptics arrive. The 1990s. The grunge era of
paleontology. In a way, yeah. Smith and Galton
enter the scene in 1990. They looked at this
entire exhausting history. Allosaurus, Triosaurus,
Ornithomimus, Coasaurus, Archeornithomimus. And
they basically just said, stop. What was their
argument against all this? They argued that the
material, remember, we are still just talking
about a few foot bones, was just too scanty.
Not enough evidence. Right. They said you simply
cannot identify it specifically enough to call
it an Archeornithomimus. They claimed it could
only be broadly classified as Theropoda. Ouch.
That's like finding a single hair at a crime
scene and the detective saying, well, it definitely
belongs to a mammal. Exactly. It's technically
true, but it's not very helpful for closing the
case. It's what we call the dubious label. Gnome
and dubium. If you look at the Wikipedia page
title for this animal today, it clearly says
Dryosaurus grandus is a dubious species. That's
where this label comes from. Because they were
saying, we don't really know what this is and
we can't pretend we do. Yes. It was an admission
of defeat in a way. So for a while. Our dinosaur
was essentially stripped of its unique identity.
It became just a generic meat eater from Maryland.
Yes. It sat in taxonomic purgatory for decades.
It was a wastebasket case all over again. Until
2016. The redemption. The redemption. Enter Chase
Brownstein. Chase Brownstein. A modern researcher
looking at this with modern eyes. Yeah. He published
a paper in 2016 that... finally brought some
much -needed clarity to this entire mess. What
did he actually find? Did someone finally go
back to the Arundel Formation and dig up the
rest of the skeleton? No, surprisingly. He looked
at the exact same bones, the very same foot elements.
But he had something that Marsh, Lull, and Gilmore
simply didn't have. What's that? Context. He
had a full century of other discoveries to compare
them to. Right. And he confirmed what Gilmore
had suspected way back in 1920, that this animal
really does belong to Ornithomomasauria. The
ostrich dinosaurs. So Gilmore is basically right
all along. In the broad sense, yes, he was. Brownstein
systematically compared the Arundel material
to dinosaurs that hadn't even been discovered
in Gilmore's time. Like what? Animals like Kinneramus
from Thailand and Ned Colbertia from North America.
Ned Colbertia? Named after Ned Colbert, I assume.
That's another famous paleontologist. An absolute
legend in the field, yes. Brownstein looked at
the metatarsal interplay. Basically how the bones
of the foot fit and lock together. And he looked
at the specific shape of those curved claws again.
He found that these very specific features linked
our Maryland mystery directly to these other
primitive ornithomimosaurs. Okay, so it's not
an allosaurus. No. It's definitely not a plant
-eating dryosaurus. Definitely not. It is an
ostrich mimic. Yes. His work completely validates
its place in that specific family tree. Even
if the specific genus name is still a bit of
a mess, which is exactly why we have the quotation
marks around Dryosaurus, we now fundamentally
know what kind of animal it was. It's just amazing
to me that it took from 1888 all the way to 2016
to simply arrive at it's an ostrich dinosaur.
That is just the pace of science sometimes. Yeah.
You often have to wait for the broader context
to catch up to the initial discovery. Right.
You can't solve your puzzle until you have enough.
pieces of the other puzzles around it to finally
see the larger pattern. So let's do a quick deep
dive into the classification as it stands today
to really ground everyone listening in what this
animal actually is. Sure. If you and I were standing
in a Maryland swamp 112 million years ago, what
are we looking at? Okay. So obviously starting
at the top, kingdom animalia, phylum chordata,
it's a vertebrate. Then down to clade dinosauria.
Right. Then we go into seritia, which are the
lizard hip dinosaurs. Yeah. Then Theropoda, the
broad group that includes everything from a massive
T -Rex down to the modern birds outside your
window. And finally, Ornithomimisauria, the bird
mimic lizards. So to visualize it, picture an
animal maybe 10 to 15 feet long. Okay, pretty
big. Bipedal, highly balanced by a stiff straight
tail. Long, slender legs, perfectly built for
high speed. Long arms with grasping hands. Absolutely
not tiny little arms like a T -Rex. Right. Functional
arms. Yes. And a small head with a toothless
beak. possibly sporting a crest of feathers.
Just darting around the floodplains. Exactly.
Snatching up small lizards, maybe stealing eggs,
maybe browsing on some plants. It was an omnivore
and likely a very skittish, fast -moving one.
It's a really vivid image. And just to recap
the exhausting trail of names, because honestly,
I think it's hilarious when you list them all
at once. Take a deep breath before you do. Okay,
here we go. It started as a monster, Allosaurus
medius. Right. Then it became a gazelle, Dryosaurus
grandus. Then a bird mimic. Ornithomimus affinis.
Then a hollow bone lizard. Colosaurus affinis.
Keeping up. Then an Asian immigrant. Archeornithomimus
affinis. And now today, we sort of vaguely circle
back to Dryosaurus grandus, but with big skeptical
quotation marks around the Dryosaurus part, fully
knowing it's actually an ornithomimus. That is
an identity crisis for the ages. It's the dinosaur
equivalent of someone changing their major five
times in college and still not knowing what they
want to do. It really is. So... What does this
all mean for us? Why should you, the listener,
care about a few obscure foot bones in Maryland
that basically can't decide on a name? I think
it matters deeply because it breaks the illusion
that science is a finished printed book. Yeah,
that's a great point. We tend to think of dinosaurs
as these rigid established facts. A T -Rex looks
exactly like this. A Stegosaurus looks exactly
like that. We see them mounted in the museum
and we think, okay, that is the absolute truth.
But in reality, paleontology is often working
with scraps. Exactly. It's not a flawless 4K
photograph. Yeah. It's a blurry, messy sketch
drawn on a napkin. And the quote unquote truth
of what Dryosaurus Grandus actually is changed
depending entirely on who was looking at it and
what specific scientific lens they happen to
be wearing that decade. Marsh had an Allosaurus
lens. Lull had a herbivore lens. Russell was
wearing an Asian migration lens. Precisely. It's
almost like the dinosaur itself evolves based
on the observer. The physical bones don't change.
They've literally been sitting in the exact same
drawer for 100 years. Right. But our fundamental
understanding of them is constantly evolving
as we learn more about the ancient world they
lived in. It also makes me think about how much
we still don't know. Like how many other dinosaurs
are sitting in museum drawers right now across
the world with the completely wrong name tag
on them? Oh, probably hundreds. Maybe thousands,
honestly. Taxonomy is constantly being cleaned
up and revised. There are wastebasket taxa all
over the place just waiting for a Chase Brownstein
to come along and take a careful second look.
And it serves as a pretty good reminder to be
humble about what we think we know right now.
Absolutely. The dubious label isn't a failure
of science. It's an honest admission that we
need more data. It's science simply saying, I
don't know yet. I want to go back to that lost
bone for a second as we wrap up. The original
Ornithomimus grandus from Montana. Ah, the ghost
specimen. It haunts me. Somewhere out there,
maybe in a dust and forgotten crate in a museum
basement, or maybe eroded away into sand on a
hillside, is the single bone that caused all
this bureaucratic trouble. It is a very provocative
thought to leave on. How many scientific names
across all of biology are anchored firmly to
fossils that no longer physically exist? Right.
We build these rigorous, uncompromising systems
of rules, like first name wins, but the physical
reality of the specimens is incredibly fragile.
Fossils get lost during wars, they're destroyed
in museum fires, or sometimes just misplaced
during bad moving days. Or someone just mislabels
a cardboard box. Exactly. But the published name
remains permanently in the literature. legally
dictating what we can and can't call a brand
new discovery made 100 years later. It's exactly
like a binding legal precedent based on a case
file that was burned in a fire. It's the ghost
in the machine of paleontology. It truly is.
Well, I think that is a perfect place to wrap
up today's discussion. We started with a muddy
detective story, went through a massive bureaucratic
nightmare, and ended up with a ghost story. Very
fitting for a deep dive into the deep past. So
next time you're at a museum and you see a neat,
tidy label on a dinosaur bone, take a closer
look. Maybe there's a wild story behind that
name. Maybe it was an allosaurus yesterday and
a dryosaurus today. And who really knows what
it will be classified as tomorrow. Exactly. Thanks
for diving in with us. Look at your own foot
elements with a bit more respect today. They're
incredibly complicated structure. They certainly
are. Catch you on the next deep dive.