4:00

to thank. They are

4:02

Amber, Anna Rose, Bradley,

4:04

L. Rex, Grace, Luke,

4:06

Gabrielle, Ellen, and Danny

4:08

Hermis. So thank

4:11

you all very much for joining. We

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episodes, episodes of InoPaleo, and

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a whole bunch of other perks. Jumping

4:58

into the news, there

5:00

are three immature dysploetosaurus skull

5:02

bones that help show us

5:05

how the dinosaur changed and didn't change

5:07

as it grew up. So

5:09

this is an example of the changes we

5:12

see during its lifetime. This

5:14

was published in Canadian Journal of Earth Sciences

5:17

by Colton, Koppok, and others. And

5:19

the question is, how did Tyrannosaur

5:22

skulls change as the

5:24

Tyrannosaurid grew up? It's

5:27

important to know because then you

5:29

can correctly identify Tyrannosaur specimens or

5:31

individuals at different ages. Oh,

5:34

I see. So that you're not accidentally

5:36

naming new species when it's

5:38

really just a juvenile of a known species? The

5:43

University of Alberta over the last century

5:45

has collected three isolated skull bones from

5:48

immature Tyrannosaurs, specifically dysploetosaurus.

5:51

These were found in Dinosaur Provincial Park in

5:53

Alberta, Canada in the Dinosaur Park Formation. The

5:56

Dinosaur Park Formation is from the late Cretaceous and a lot of

5:58

dinosaur skeletons have been found in the dinosaur park. been found there,

6:01

often with preserved soft tissues, and the

6:03

formation is named after Dinosaur Provincial Park,

6:05

which is a UNESCO World Heritage Site.

6:09

Tyrannosaurs that have been found there include dysplidosaurus

6:11

and gorgosaurus. Dysplidosaurus

6:13

has also been found in the nearby Oldman Formation,

6:15

which is also from the Late Cretaceous. For

6:19

this study, they looked at

6:21

the premaxilla, jugal, and lacrimal.

6:23

So the tip of the snout, the

6:26

bone on the side of the face, and then

6:28

a part of the eye socket. Those are the

6:30

three isolated bones. And the

6:32

team compared them to tyrannosaur fossils found

6:34

in both Dinosaur Park and Oldman Formation

6:36

in Alberta. They found that

6:38

these three parts of the skull look the

6:40

same in dysplidosaurus as it grew up. They're,

6:44

quote, constrained through ontogeny. There's

6:47

some small details that change, like some slight

6:49

changes in openings and depressions in the bones.

6:53

But it helps, knowing these details,

6:55

to confidently identify, no matter what

6:57

the age, whether a fossil is

6:59

dysplidosaurus or gorgosaurus in this case.

7:01

Okay. Because I was wondering when

7:04

you say there are three bones and they're isolated,

7:06

just like little pieces of the skull, and they

7:08

show how dysplidosaurus changed as it grew. My

7:11

question was going to be, how do you know it's

7:13

dysplidosaurus changing as it grows? And

7:15

I guess the answer is because it

7:17

didn't really change. Yep, exactly. It's more

7:19

a question of how it doesn't change

7:21

as it grows. Yes.

7:24

So they applied their findings to a

7:26

skull and a jaw, and I think

7:29

part of a skeleton that was classified

7:31

as dysplidosaurus, but they found that that

7:33

specimen was actually gorgosaurus instead. And there's

7:35

been a lot of debate on this

7:38

particular individual. It's a cool

7:40

one too. The skull has bite marks on it.

7:42

It's an immature individual. Most

7:44

of those marks happen while the animal was alive.

7:46

So the poor dinosaur

7:48

had numerous injuries or infections. And

7:52

we know that it was alive because there's

7:54

evidence of healing. Well, it's made it through,

7:56

at least for a while. For

7:58

a while. possible another tyrannosaur

8:00

bit its face, but that doesn't account for

8:03

all of the injuries or infections. And

8:05

there is evidence of bites that happened

8:07

after it died, probably from a large

8:09

tyrannosaur based on the spacing between the

8:11

teeth marks. That's intense.

8:14

Yes. And

8:16

now we know it was probably a

8:18

gorgosaurus. Mm-hmm. Yeah, so looking

8:20

at the details and the

8:22

fossils can be very helpful. Yeah. You have

8:24

to have an eye for it though. And

8:26

this also seems like the kind of thing

8:29

that could be extrapolated to stuff like nanotyrannus

8:31

debates, because if you know

8:33

that those parts of the skull don't change

8:36

over time, you can check, well, did nanotyrannus

8:38

change in that way or not? Yeah,

8:41

that would be interesting to see.

8:43

Next up, there's a paper that

8:45

found that living birds have high

8:47

EQs, which they evolved from non-avian

8:50

dinosaurs. Now we've got the evolution

8:52

side of change. This was published

8:54

in Nature Communications by Logan King and others,

8:57

and they studied the brain endocasts of

8:59

a number of cetachosaur specimens. So they

9:01

could see a whole growth series there,

9:04

because there are so many cetachosaur that

9:06

have been found. Mm-hmm. And these individuals,

9:09

they were under one year old. They

9:11

were also seven, eight, and 10 year olds of

9:14

cetachosaur. They also

9:17

looked at specimens of

9:19

lambiosaurus, kerithosaurus, tyrannosaurids,

9:22

zanabazar, and an unnamed troodontid. That was

9:24

like zanabazar. That's a fun name. That

9:26

is a fun name. And

9:29

then they compared all those specimens

9:31

to chickens and alligators, because they

9:33

wanted to see the evolutionary changes

9:35

to brain development. They found that

9:37

the non-avian dinosaur brains developed differently

9:39

to alligators and crown birds. Ornithischian

9:43

and the non-avialin theropods,

9:46

so they're not birds. Yeah. They

9:49

shared a common shape to size

9:52

relationship that guided their brain development

9:54

and evolution. So that

9:56

means they probably evolved or that characteristic

9:58

evolved in a common animal. And that's

10:01

basically that as their body

10:03

got bigger their brain got

10:05

proportionally bigger Interestingly

10:08

bird brains look more like

10:10

juvenile non avial and dinosaurs.

10:13

So the bird brains look more like they're non-bird

10:16

relatives So

10:21

that means that the brains didn't just get

10:23

smaller or go through miniaturization as Birds

10:26

evolved, but it was more about paid amorphous Where

10:29

some parts of the brain had

10:31

juvenile characteristics, although not all the

10:33

parts did. Yeah, paid amorphous

10:35

is when you have characteristics

10:38

in an adult animal that the

10:40

ancestor had only when they were

10:42

young But he also

10:44

said that they have a high EQ

10:47

which is that encephalization quotient, which is

10:50

Essentially a ratio of the brain

10:52

size to the body size of

10:54

the animal So that bigger brain

10:56

size I guess was also true

10:59

Potentially in the juvenile dinosaurs

11:03

in the non avian ones, you know But

11:05

they just kept up that big proportional brain

11:08

size as they got older. It

11:10

served the birds well You

11:14

remember seeing before that there was this

11:16

big shift sort of right after the

11:18

anchor Tashes extinction where some of the

11:20

birds that Eventually evolved into things like

11:22

crows were starting to get much

11:25

bigger brains So there was

11:27

something that tipped the scales after

11:29

the Cretaceous Paleogene boundary

11:31

that made them really get a lot

11:34

smarter Probably but really just bigger

11:36

brains. It does seem like

11:38

if they've got bigger brains, they probably were

11:41

smarter Yeah, at the very least

11:43

they had better senses. Mm-hmm So

11:45

yeah, that's two types of growth in

11:48

dinosaurs brain growth and skull

11:51

growth Yeah, I

11:53

was thinking more growth over a long period

11:55

of time Millions of years

11:58

and then growth in a lifetime of a dinosaur That

12:00

too. This

12:02

next paper I found really interesting.

12:06

It's that scientists are cautioning how

12:08

we estimate sizes and

12:10

body shapes of extinct animals. And

12:12

you have to be careful what animals you compare them

12:14

to, to come up with these estimates. Yes.

12:17

This was published by Joel Gafford and

12:20

others in Ecology and Evolution. And as

12:22

we talk about on this show, a

12:25

lot of extinct animals, especially dinosaurs, are

12:27

known from incomplete fossils. So

12:30

when you're trying to reconstruct their

12:32

bodies, you have to compare the

12:35

fossil specimen to other animals to

12:38

kind of fill in the gaps. And

12:40

you can use either living animals or extinct

12:42

animals where you've just got more fossils that

12:44

are preserved. But there's

12:47

a lot of limitations here, and

12:49

that can lead to controversies and

12:51

inaccuracies, which has

12:53

this downstream effect because it can

12:55

affect later studies because those

12:57

studies might use the inaccurate depictions. I

13:01

see. So it can compound because

13:03

if you estimate your dinosaur size

13:05

based on the wrong

13:07

assumptions, and then someone looks at your estimate

13:10

for their dinosaur size, then you can

13:12

just have bad data following

13:14

bad data. It's kind of like a game of telephone.

13:17

Although I don't know how much it changes if you're able

13:19

to cite directly. Yeah. But

13:23

yeah, body size is important to know

13:25

because it helps us figure out an

13:27

animal's ecological niche, like what they ate,

13:30

how they moved, how they reproduced, the

13:32

predator and prey relationships, for example. So

13:36

for this paper, they actually didn't look

13:38

at dinosaurs. They looked at four case

13:40

studies of marine megafauna, big

13:43

animals that lived in the water. Dungalosteus,

13:46

Helicoprion, Odidas, also

13:49

known as megalodon, and Perusidus.

13:52

And they represent a range of

13:54

body sizes, niches, and geological time

13:57

intervals. Dungalosteus, for example,

13:59

lived in... the late Devonian, it

14:01

was a Placoderm, a bony

14:03

fish with armor and

14:05

guillotine like jaws or maybe guillotine, I've

14:07

heard it pronounced both ways. And

14:10

it was found to be much stockier and shorter than

14:12

previously thought, which we've talked about on this show, although

14:14

I think we might have talked about it in I

14:16

Know Paleo. I think it was I Know Paleo. Yeah,

14:19

because it had always been assumed

14:21

that basically these jaws by the

14:23

size of them, they stretched

14:26

out a typical sort of fish shape

14:28

behind it. And they're like, Oh, it

14:30

was, you know, a ginormous

14:32

fish super long. And then they discovered,

14:34

Oh, wait, we actually think that they

14:36

were really stocky. They were a lot

14:39

shorter proportionally than what you see in

14:41

a lot of modern fish. So maybe

14:43

it was only half or a third

14:46

the length of these previous estimates. Yeah,

14:48

very different. Then we've got

14:50

Helicoprion, which is from the Permian

14:52

and that's a jawed fish. It's the one with the

14:54

rolled up teeth. I like to think of

14:56

it as it looks like

14:59

a spiky Cinnabon. Yeah,

15:02

I guess so. I

15:04

don't know what I think of it as

15:06

I just think of it like a conveyor

15:09

belt sort of spiraling out. So that's just

15:11

gonna have continuous more teeth. But I think

15:13

it actually kind of goes the other way,

15:15

like whirls into swirls. Yeah, maybe more like

15:17

a whirlpool situation, maybe descending into the middle.

15:19

Or if you're constantly thinking of food like

15:21

me, a Cinnabon. But

15:27

it was found to have a shorter lower

15:29

jaw and a shorter body than we used

15:31

to think. Oh, just like Dumpkolastus. Yes. Then

15:34

there's Otodus, which

15:36

lived in the mid-Myocene to early

15:38

Pliocene. It's a shark with gigantic

15:40

teeth. The species name

15:42

is Megalodon. That's why I said that

15:45

earlier. It was found that it

15:47

actually wasn't a fast swimmer

15:49

and it was more slender than previously

15:51

thought. Really? So less great white

15:54

sharky. Yeah, still gigantic

15:56

teeth though. And

15:59

then Perusae, Eucetus is

16:01

from the late middle Eocene, and it's

16:03

a large archaeocene. Archaeocedes

16:05

are ancient whales. They're

16:08

early cetaceans, and cetaceans include

16:10

whales, dolphins, and porpoises. And

16:13

that one was also found to be lighter than

16:15

previously thought. It's just like dinosaurs. They

16:17

all seem to shrink over time. Yeah. I

16:19

always feel like when they find these new animals,

16:21

there's a lot of enthusiasm. It's like, imagine how big

16:24

it could be. And then you look a little

16:26

more closely at it, and it's like, well, maybe

16:28

not quite that big actually. Well,

16:31

so they talk about that in the paper

16:33

a little bit, that there's this tendency to

16:35

overestimate size. And sometimes it's

16:37

because there's a pressure to make

16:40

it seem bigger, to get more

16:42

public interest, or you fear burning

16:44

bridges in the academic community, or

16:47

museums restricting access to specimens, just

16:49

to name a few reasons. Interesting.

16:52

I hadn't thought of those before. Me

16:54

either. And then sometimes you also get

16:56

a backlash, as they say, quote, from

16:58

the ever-growing fan communities of prehistoric organisms

17:01

on the internet. Yeah. I

17:03

remember that one, Dunkelosteus, was found to be a lot smaller. I've

17:05

seen it with some sauropods too. It's like, that's my favorite. What

17:07

do you mean it's not 100 feet long? Yes,

17:10

so that can make it difficult when you're trying to

17:13

figure out the size of an animal. But

17:16

knowing, or getting closer

17:18

at least, to their actual sizes helps

17:21

us better understand gigantism and body

17:23

size evolution of animals. So

17:26

the paper, they said the issue is that

17:28

size estimates need to be revised sometimes, just

17:30

that there's a big difference in size estimates

17:32

for some animals, because sometimes an estimate is

17:35

twice as big as another for the same

17:37

animal. And that can really affect our understanding

17:39

of that animal. So you

17:41

have to be careful what you use as proxies when you're trying to

17:43

fill in those gaps. Yes, I

17:45

found this to be by far the most challenging

17:47

part of writing a book about

17:50

dinosaurs, where we needed to put in

17:52

our facts about the size

17:54

of the dinosaurs, deciding

17:56

what single number to put for an estimate

17:58

for the last one. length of a dinosaur,

18:01

I lost some sleepless, I had some

18:03

sleepless nights over that one. Because

18:07

it just summarizing

18:09

an entire animal down to one

18:11

length estimate and one weight estimate

18:14

is so challenging. Yes.

18:16

Well, you think about humans, we have

18:18

a wide range of sizes. Yeah. And

18:21

a lot of times you can't tell because

18:24

what I've found very often is people will

18:26

give a range of size estimates. So they

18:28

say, oh, it was somewhere in the five

18:30

to seven meter range. But

18:33

then sometimes what happens is people will say, oh, it

18:35

was up to seven meters long. It's

18:37

like, well, really what they were saying is

18:40

we think it was about six plus or

18:42

minus one meter. They weren't saying that within

18:44

the population, they ranged from five to seven

18:47

meters. They were saying, we don't know how

18:49

big it was. It was somewhere in the

18:51

five to seven meter range. So finding the

18:53

primary sources where the actual estimates come from,

18:56

or better yet, if you can find the

18:58

actual individual bones and see how big they

19:00

are and do a consistent analysis comparing different

19:03

members within these dinosaur groups, then you

19:05

can kind of see, okay, well, if

19:07

I'm saying Stegosaurus is 30 feet

19:10

long and I'm saying Kentrosaurus is 20 feet

19:12

long, but they had the femur that was

19:14

the same length, they should probably have a

19:16

much closer length estimate. Mm-hmm. We'll

19:19

see what kind of feedback we get when the book comes out. Yeah.

19:22

There's a couple where I wonder what people will say.

19:26

But that's a nice segue to our book segment, which

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to 500 500 that's

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text imagine. 500, 500. So

22:03

thank you, Garrett, for that nice segue into our book

22:05

segment. It

22:07

was unintentional, but I can pretend it

22:09

was intentional. Yeah. I've

22:12

mentioned before we've gotten to read a lot of

22:14

dinosaur books lately, and thank you to the authors

22:16

and publishers who've sent them our way. And

22:19

I just wanted to mention a couple more

22:21

of this episode, specifically the nonfiction dinosaur books,

22:24

because so far we've talked about kids' books

22:26

and fiction books. And of course, we can't

22:28

leave out the nonfiction books. There's probably more

22:30

nonfiction dinosaur books than fiction

22:32

or kids' dinosaur books. Oh,

22:34

maybe not kids. That's

22:36

hard to say. But most kids' books are

22:38

nonfiction dinosaur books. True, true. I'm

22:42

talking about nonfiction books for adults. Stay

22:45

tuned. We will also be talking

22:47

very in-depth soon about a

22:49

particular nonfiction book. And in

22:51

fact, we'll be doing our own version of a book club

22:53

around it. We'll be sharing more details. Yeah, we're going to

22:55

try out a book club. That'll be fun. Yeah.

22:58

All right, so the first book I want to

23:01

mention is A History of Dinosaurs in Fifty Fossils

23:03

by Paul Barrett, which I

23:05

think is a really good overview and a

23:07

nice focus on the fossils. In

23:09

the book, it talks about what is a dinosaur

23:11

as well as the origins and history of dinosaurs,

23:13

like their rise and fall, if

23:15

you will. Now

23:17

I just think of the Steve Broussati book. It

23:20

also goes over the main types of dinosaurs,

23:22

dinosaur biology, like how they breathed and walked

23:24

and what their brains looked like. And

23:27

each chapter focuses on a single

23:29

dinosaur fossil. It's

23:32

not a definitive list, but it reflects the author's

23:34

interest, as he says in the introduction. Yeah,

23:37

if it's only 50 fossils, you're not going to

23:39

be able to cover that many dinosaurs. Yeah. But

23:42

they include megalosaurus, mentellosaurus,

23:45

heurisaurus, coelophysis, mesospondylus,

23:49

pantedrachae, which is

23:51

a pretty newly discovered one, just to name a few

23:53

of the fossils. That's a lot of Southern

23:55

United Kingdom, which makes sense for

23:58

the author. Yes. But

24:00

then of course you've also

24:02

got famous ones like Stegosaurus,

24:04

Triceratops, Diplodocus, Spinosaurus, Maesora, Tyrannosaurus

24:06

rex. There's a whole

24:08

chapter called End of an Era. And it talks

24:11

about the history of when the fossils found and what we've learned

24:13

from studying it. It's got really nice

24:15

paleo art as well as images of the fossils.

24:19

Yeah, and it's a good answer to Ryan

24:21

the Biochemist's question. We had an episode

24:23

a couple of weeks ago where they

24:26

asked about a book where you could

24:28

see the actual fossils rather than just

24:30

reconstructions. And this book I

24:32

think fits that bill pretty well. Yeah,

24:35

yeah, there's a cool Coelophysis photo in

24:37

its death pose. There's fossils

24:39

of Nyasosaurus, which I don't think we

24:41

often see pictures of that one.

24:44

It's pretty incomplete. Yeah, there's

24:47

a beautiful Titanosaur egg and the inside of

24:49

it, which is now filled with brightly colored

24:52

agate. Nice. Had to bring that one

24:54

up. I

24:57

think that's the one, is that the one that

24:59

was in their collection at the Natural History Museum

25:01

in London and then they discovered that it was

25:03

a dinosaur fossil? Yes, it's

25:06

a pretty cool one. And

25:09

then the next book I wanna

25:11

mention is called Macroevolutions Reflections on

25:13

Natural History, Paleontology and Steven J.

25:15

Gould by Bruce S.

25:17

Lieberman and Niles Eldridge. It's

25:20

a book of 13 essays and it

25:22

examines how paleontology intersects with pop

25:24

culture, philosophy, music, and the history

25:26

of science. And

25:28

it's all with an eye on the career and legacy

25:30

of Steven J. Gould, who's

25:33

known for his science and popular science, mainly

25:35

300 essays in the Natural

25:37

History Magazine. And in

25:39

terms of evolutionary biology, he

25:42

developed along with Niles Eldridge,

25:44

the theory of punctuated equilibrium

25:46

where evolution has these long

25:48

periods of evolutionary stability that's

25:51

infrequently punctuated by swift periods of

25:53

branching off. Yeah, it's really interesting.

25:55

It is. So the authors knew

25:57

Gould really well, they say so in the preface.

26:00

They worked together for decades. And the

26:02

essays, they're easy to read. They weave together

26:05

science with personal stories. The

26:07

first essay, for example, is called The Three

26:09

Musketeers of Macroevolution. Although

26:11

it sounds like that caused some trouble because I quote,

26:14

never join a gang, especially in academia. There

26:20

are kind of gang-like groups in

26:22

academia sometimes. Yeah. So

26:25

there's all kinds of references

26:27

ranging from Steven Tyler from Aerosmith

26:30

to Ernest Shackleton, the Antarctic explorer,

26:32

to the mighty mighty boss tones,

26:34

Emmanuel Kant, the Lion

26:37

King, Beavis and Butthead, Jaws,

26:39

all kinds of ways to tie it

26:42

back to paleontology. Sounds like

26:44

a good book. Yeah. It was definitely

26:46

entertaining. I might have to read it. Sabrina

26:48

reads most of the books that we get because she reads

26:50

so much faster than me. You eventually read

26:52

them too. Yeah. It takes me a

26:54

while. If you

26:58

ever have a book in audio form, that's

27:00

the way to get Garrett to consume

27:03

it quickly. I'm all about those

27:05

audio books. Also sometimes I get

27:07

my various apps to read me

27:10

text so that

27:12

I can get through it faster. All

27:16

right. And now on to our Dinosaur of

27:18

the Day, Sugeosaurus, which was a request from

27:20

Paleo Mike 716 via our Patreon

27:23

Discord. So thanks. It

27:25

was a therosinasauroid dinosaur that lived

27:27

in the early Cretaceous in what's

27:29

now China in the Xiago Formation

27:31

and the Zhongguo Formation. To

27:34

me, it looks really vulture-like

27:37

but obviously supersized with

27:39

the neck and the head. Well, it

27:42

doesn't have a bald head, but it's

27:45

just the way it's standing in

27:47

the Paleo art is vulture-like,

27:49

but it's also kind of Skeksis-like. Yeah.

27:52

I think Skeksis is a good description. From Dark

27:55

Crystal. Although a lot more people probably know what

27:57

a vulture looks like than a Skeksis. You

28:00

never know. Maybe we should explain

28:02

what a Skeksis is. Yeah. How

28:04

do you even describe what a Skeksis is?

28:06

It's basically a dinosaur in the dark

28:09

crystal, which is a Jim Henson movie

28:12

and later TV show, but they're

28:14

sort of creepy

28:16

creatures that are sort of featherless,

28:19

but it's sort of, to me, it's kind of implied

28:21

that they're decaying kind of.

28:23

So it's like they're missing their feathers not

28:25

because they're non-avian dinosaurs, but because they've just

28:27

lost them because they're not doing

28:29

so well. But

28:31

yeah, they have big arms and big claws

28:34

and stuff. And I think that does make

28:36

them pretty therosinosaurus-like. Yeah. I

28:38

think also the paleoart that I saw

28:40

of pseudosaurus makes it look a little

28:43

hunched. But

28:46

pseudosaurus in

28:48

life didn't really look like a Skeksis

28:50

in that it, I don't

28:52

think it looked like it was decaying. Yes.

28:55

We don't really know what it looked like with all

28:58

that stuff on it, but it did probably not have

29:00

tons of huge feathers on it, although

29:02

it did have sort of bird-like proportions

29:04

sort of roughly kind of like an

29:06

ostrich or something with a longer tail.

29:09

But you would have been able to see its

29:11

big fingers rather than them being covered in wing

29:13

feathers. Right. And it had very

29:15

long arms and claws and it walked on

29:18

two legs and it had a long tail.

29:21

Being a therosinosauroid, it was an herbivorous theropod,

29:23

which I think that's probably why I like

29:25

this group so much. Because usually

29:28

you think theropods think carnivores. Mm-hmm.

29:31

Yep. It adds to the weirdness. Yeah.

29:34

It's double weird because it looks like one of

29:36

the most ferocious theropods because it has these huge

29:38

claws, but it turns out

29:40

that it probably just wanted to eat plants.

29:43

Yep. Maybe they were more for defense.

29:45

We don't know for sure because some herbivores are

29:47

pretty ferocious, but it wasn't being ferocious to eat

29:49

things. Yes. And

29:51

fun fact, therosinosaurs were first thought to

29:53

be giant turtle relatives. Which

29:56

is very different from what we think

29:58

now. Yeah, they thought the claws were

30:01

like flippers. Yes. So, Sugisaurus was large.

30:03

It was estimated to be up to

30:05

20 feet or 6 meters long and

30:08

weigh over 3 tons. And

30:10

it helps show that their xenosauroids got

30:13

large early on. It also had one

30:15

of the longest known upper arm bones

30:17

of any theropod. I

30:20

guess a lot of theropods, nonavian, should

30:22

say, when we talk about them, we talk

30:24

about their short arms. Sugisaurus

30:26

had a wide body. It

30:29

probably waddled and

30:31

had a large belly, as well as

30:33

robust legs and a short tail, long

30:35

claws and a long neck, and a beak. And

30:38

it may have had some feathers that's

30:40

based on its relative Bapiosaurus having

30:43

been found with feathers. Its

30:46

vertebrae weren't that light. They

30:49

weren't really pneumatized or hollow.

30:52

Maybe that's why it probably waddled. I'm

30:55

guessing the waddling probably had to do with the wide gut and

30:57

the shorter legs. Yeah, that would make more

30:59

sense. The

31:02

type species is Sugisaurus

31:04

megatheriodes. Sounds like megatherium,

31:06

like the big ground sloth.

31:08

Well, that's what it refers to, is

31:10

that it looked like the giant ground

31:13

sloth, megatherium. That's another good way to

31:15

describe it, in addition to Skeksis, which

31:17

is a ground sloth. All

31:19

kinds of fun ways to describe

31:21

this one. The genus name means

31:23

Sujo lizard. It refers to Sujo,

31:26

which is the old name for the Geochron area

31:28

where the fossils were found. There

31:31

were two specimens found during fieldwork in 1999 and 2004, and then it

31:33

was described in 2007 by

31:37

Dacengli and others. If

31:39

you put it all together,

31:41

Sugisaurus megatheriodes means giant sloth-like

31:43

reptile from Sujo. The

31:46

authors said that Sugisaurus might be the

31:48

same as Nanshungosaurus, that's

31:50

in quotes Bolini,

31:52

which is a therazinosauroid named earlier that was

31:55

found in the same area, but it's known

31:57

from very few fossils, so it's hard to

31:59

conclude. compared the two. And maybe

32:01

the fact that there were so few fossils made them

32:03

put it in quotes because they're a little spurious

32:06

on whether or not it's valid. Seems so.

32:09

The howl type of sujursaurus is a

32:11

partial skeleton, no skull was found. It

32:14

includes a right upper arm, right

32:16

shoulder, partial ribs, parts of the

32:18

hips, and ten back vertebrae, ten

32:20

backbones. And then a more

32:22

complete skeleton was described in 2008 and that includes

32:25

more back vertebrae, the hips, part of the neck,

32:27

and both femora, or thigh bones. Those

32:30

are the fossils that were found in 2004. They

32:33

know that both of these come from

32:35

the same dinosaur, sujursaurus, because both of

32:37

them, they found the left pubis and

32:39

they found that they looked the same.

32:43

They also found an isolated tooth. Sujursaurus

32:46

lived on a warm semi-arid plain with

32:48

shallow temporary lakes. And

32:50

other dinosaurs that lived around the same

32:52

time and place include ornithomimosaurs like beishonglong,

32:55

tyrannosauroids like xionguanlong,

32:58

the small neoceratopsians like aurora

33:01

seratops, as well as hadrosaurs

33:03

and sauropods. I

33:05

love a big weird therosinosaur

33:07

or therosinosauroid, I should

33:09

say. Me too. Especially

33:12

when we can come up with all

33:14

these comparisons like sloth or skexis or

33:16

vulture. And

33:20

then I like having the juxtaposition with, like

33:22

we do today with our fun fact, which

33:24

is the smallest known microrafter that had a

33:27

thigh bone less than five centimeters or two

33:29

inches long. Just so different.

33:31

It's very small. This was

33:33

published in historical biology by Ranhui

33:35

Wang and Rui Pei. They

33:38

studied this nearly complete skeleton, it

33:40

includes most vertebrae, the complete tail,

33:42

ribs, left arm, both legs, parts

33:45

of the shoulder. The

33:47

tail has 29 bones or 29 cottle vertebrae. The

33:51

fercula, the wishbone is boomerang shaped.

33:53

I liked that description. And

33:56

then we've got the femur, the thigh bone that's

33:58

less than five centimeters long or almost two inches.

34:00

So this is

34:02

the smallest Trameosaur individual known from

34:04

the Jeho Bioda so far. Okay.

34:08

The smallest raptor from the Jeho Bioda,

34:10

which is, it's not like, oh,

34:13

that's an asterisk. That's just some

34:15

small niche area. The Jeho Bioda

34:18

is where most of

34:20

these bird-like dinosaurs are found. At least it's

34:22

the biggest spot where you'll find all these.

34:25

Yes, and microraptor is one of the most

34:27

common dinosaurs found there. So

34:29

out all the microraptors so far,

34:31

this is the smallest one. Out

34:34

of, I think, hundreds. Yes. Although

34:36

in the paper they said that a lot of

34:39

microraptors have been found, but not many have been

34:41

described or reported. So I'm wondering if

34:43

there's some even smaller ones in there. Yeah.

34:46

It was a juvenile, the smallest

34:49

known one. It was less than one year old

34:51

based on histology. There's some fusion

34:53

in the hip area though, whereas

34:56

some other parts of the skeleton are unfused, like

34:58

in the shoulders, ankles, and some of the back

35:00

vertebrae. And the author's caution, well,

35:02

this means that you can't

35:05

just use looking at bones,

35:08

skeletal fusion, seeing the bones that are fused

35:10

to decide if an individual is a juvenile

35:12

or an adult microraptor, and you

35:14

should use histology when possible. It's

35:17

just not always possible because histology means

35:19

cutting into the bones and not everybody

35:21

wants you to cut up their fossils.

35:23

Sometimes looking at fusion is the best you can

35:26

do. That's true. And even in this one, the

35:28

vertebrae aren't fused, so there's still some

35:31

clues. That's true. But

35:33

interestingly, the holotype of microraptor jowianis was

35:35

thought to be an adult or sub-adult,

35:38

and that's based on fused bones in

35:40

the hips. Oh, I see. I see where

35:43

they're coming from now. If you're looking

35:45

at just one part of the skeleton

35:47

being unfused or

35:49

fused, the other parts of

35:51

the skeleton could be different, telling a different story,

35:53

so you get misleading results. Right. Because in this

35:55

case, if they didn't do histology and they just

35:57

looked at the fusion in the hip area, you

36:00

might think, well, mycoraptor could grow

36:02

really small. Or name a new

36:04

species. Yeah. Or

36:06

a new genus, nanoraptor. Yeah. And

36:09

then there was one comment on the dinosaur

36:11

mailing list that the fusion in the hip

36:13

bones early on could help show that mycoraptor

36:15

was able to run at a young age

36:17

and it could maybe run just as well

36:19

as an adult mycoraptor. Sort of

36:22

showing priorities, the things that fused first because it

36:24

needed to get there in the development.

36:27

Also, its first toe was elevated and

36:29

not reversed. So that also shows that

36:31

as a juvenile, mycoraptor wasn't better suited

36:33

to be in the trees. It's

36:35

possible it didn't live any differently

36:37

from the adults since adult mycoraptor don't seem

36:39

to have any special adaptations for climbing trees.

36:43

So interesting ideas too. Yeah. Things

36:46

we know from the micro mycoraptor. Well,

36:50

that wraps up this episode of I Know

36:52

Dino. Thank you for listening. Stay tuned next

36:54

week. We'll have even more dinosaur news for

36:56

you. And in the meantime, especially

36:59

if you have a cool dino project

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Yes. Thanks for

37:11

listening and until next time.