Join Adele and guest Dr Nathan Smith on an adventure through the Jurassic forests of Antarctica (180 million years ago) as we talk about one of the coolest dinosaurs, Cryolophosaurus (the overlooked cousin of Dilophosaurus).
We also touch on pterosaurs from Madagascar, fieldwork in frozen lands, the advantages of a pompadour and why this theropod is nicknamed Elvis!
Links:
A Crested Theropod Dinosaur from Antarctica
Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution
The phylogeny of Tetanurae (Dinosauria: Theropoda)
This episode is brought to you by Dinosaur Trips! Explore the world and see the best museums, meet experts and even dig up real dinosaurs. For more info visit dinosaurtrips.com and email zach@dinosaurtrips.com about the Badlands and Beyond Trip.
Dinosaur Trips
It's been 66 million years. Why wait any longer? Join an upcoming trip!
Pals in Palaeo @palsinpalaeo
Host: Adele Pentland @palaeodel
Online Store
Transcripts
The Pals in Palaeo Cover Art
Jenny Zhao Design @jennyzdesign
Crumpet Club House@crumpetclubhouse
The Pals in Palaeo Theme Music
Hello Kelly @hellokellymusic
Podcast Producer + Editor
Jean-César Puechmarin @cesar_on_safari
Podcast Editor
François "Francy" Goudreault @hellofrancy
Join Adele and guest Dr Nathan Smith on an adventure through the Jurassic forests of Antarctica (180 million years ago) as we talk about one of the coolest dinosaurs, Cryolophosaurus (the overlooked cousin of Dilophosaurus).
We also touch on pterosaurs from Madagascar, fieldwork in frozen lands, the advantages of a pompadour and why this theropod is nicknamed Elvis!
Links:
A Crested Theropod Dinosaur from Antarctica
Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution
The phylogeny of Tetanurae (Dinosauria: Theropoda)
This episode is brought to you by Dinosaur Trips! Explore the world and see the best museums, meet experts and even dig up real dinosaurs. For more info visit dinosaurtrips.com and email zach@dinosaurtrips.com about the Badlands and Beyond Trip.
Dinosaur Trips
It's been 66 million years. Why wait any longer? Join an upcoming trip!
Pals in Palaeo @palsinpalaeo
Host: Adele Pentland @palaeodel
Online Store
Transcripts
The Pals in Palaeo Cover Art
Jenny Zhao Design @jennyzdesign
Crumpet Club House@crumpetclubhouse
The Pals in Palaeo Theme Music
Hello Kelly @hellokellymusic
Podcast Producer + Editor
Jean-César Puechmarin @cesar_on_safari
Podcast Editor
François "Francy" Goudreault @hellofrancy
Today on the show, we're talking about our first theropod dinosaur, Cryolophosaurus! This episode we talk about ancient Antarctica, fieldwork in the frozen tundra and the dinosaurs from the Early Jurassic.
What’s cooler than being cool? Ice cold
Pals in Palaeo presents Cryolophosaurus
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Welcome to Pals in Palaeo the show filled with facts on your favourite fossils. Each episode, we talk Form, Function and Family Groupings, plus prehistoric pop culture at the end of each episode.
I'm your host, paleontologist and PhD student, Adele Pentland. You can keep up to date with the show by following me on Instagram @Pals in Palaeo. Let's get into today’s episode
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Pals in Palaeo acknowledges the Traditional Custodians of the land throughout Australia, and recognises their connections to land, sea and community.
I'd like to pay respect to the Elders past, present and emerging, and extends that respect to all Aboriginal and Torres Strait Islander peoples today. This episode was recorded on Koa country, in Winton, central western Queensland.
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I'm very excited to be talking about fossils from Antarctica on today's episode. You might’ve realised that a lot of the time the show focuses on fossils found in Australia because, I'm Australian and I think we've got some cool stuff that's severely underrated but, I thought it was time to expand our horizons.
Still I wanted to talk about something that doesn't get a lot of airplay and Cryolophosaurus ticks all those boxes.
My gut feeling, is that if you walked up to someone on the street and asked them, "what's a dinosaur from Antarctica?" they'd be surprised to know that any fossils have been found there at all, and its not just penguins.
I mean, yes penguins are dinosaurs because birds are descended from dinosaurs but you know what I'm trying to say here.
There's a real air of mystery about Antarctica and while searching for fossils in such a remote part of the world is a lot of work, as we'll discuss later, there's a big pay off. - - -
Before we talk about Cryolophosaurus, we've gotta ease into the episode and start with our Random Fossil Fact as a warm up.
As the name suggests, it's not normally related to the rest of the episode but today I thought I'd try something different and attempt to tie today's fact in with the main topic, Cryolophosaurus.
Today's Random Fossil Fact is that western scientists found pterosaur fossils from Antarctica before Madagascar.
Just so we're all clear, pterosaurs AREN'T dinosaurs. They're flying reptiles. And calling this group 'pterodactyls' instead of pterosaurs is equivalent to calling all dinosaurs 'Tyrannosaurs'. Let that sink in for a minute. It's all kinds of wrong. So stop mislabelling things and join the winning team.
And in case you're wondering why I care so much about pterosaurs and getting their name right, it's because I mostly work on them. They are my favourite animals but yeah, that's probably because I spend so much time working on them.
And hey, who knows? In 20 years time I might be working on something completely different and I'll have a new favourite. But, for what it's worth, David Attenborough is also a big fan of pterosaurs.
I can't remember if they were his favourite animals overall, or just his favourite extinct animal, but yeah. He knows a lot about animals and is a man of discerning taste, so he probably knows what he's talking about.
Anyway, I did not mean to bring David Attenborough into this so let's actually talk more about the random fossil fact. So the first pterosaur fossil from Antarctica was mentioned in 1994.
Almost a decade later, the first pterosaur remains from Madagascar, two teeth were described in 2003.
I was shook by this fact since it's so stinking hard to collect fossils from Antarctica. This is mainly because most of the rock outcrops are covered in ice. Not only that, but obviously there's limited infrastructure on Antarctica itself, and you can't just hop on a plane and get there.
Even though the teeth from Madagascar have been described, the Antarctica pterosaur from the Jurassic is still waiting in the wings.
Seriously though, it's been almost 30 years since the Antarctic pterosaur was collected, and as of this recording, the specimen has never been fully described.
I've got the inside scoop that a team of researchers are working to remedy this and having seen a cast or replica of the specimen myself I can't wait to hear more about it.
That first Antarctic pterosaur was also found with the only known specimen of, you guessed it, Cryolophosaurus. And with that, let's turn our attention to theropods and talk more about this very cool and unusual dinosaur.
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Before we talk about the Form and Function, I want to get into some basic facts and talk more about the discovery of this dinosaur.
Cryolophosaurus is monogeneric, so there's only one species within the genus.
By the way, if you have trouble remembering what monogeneric means, and you're a Simpsons fan like I am, think back to the Monorail episode, where he's explaining what monorail means. "mono means one, and rail means rail" and in the words of Lyle Lanley, that concludes are intensive training.
Non Simpsons fans, you're gonna have to find your own way of remembering mono means one.
OK so the OG Cryolophosaurus specimen, the holotype specimen, was collected from the Central Transantarctic Mountains in 1991 from rocks dating back to the Early Jurassic, in this case, these sediments are 180 million years old.
What's cool about this, is that this is super early in the evolutionary history of dinosaurs which makes it an incredibly important research specimen. It also makes the relative size of this theropod even more impressive, but more on that later.
In the Early Jurassic most of the world's landmass is stuck together forming the massive supercontinent Pangaea.
I should also point out that in the early Jurassic Antarctica isn't covered in ice.
So when Cryolophosaurus was alive, it was living in a forested environment. The climate during this time, would've been similar to modern day southern Chile with humid conditions and mild temperatures.
Cryolophosaurus was collected by a team of American researchers from Augustana College, with members of the expedition party including, William Hammer and William Hickerson, the two paleontologists who went on to name and describe Cryolophosaurus, as well as David Elliot, the person who originally found the specimen. Elliot by the way is spelt with two L's and one T.
The Cryolophosaurus holotype specimen includes part of the skull with articulated mandibles or lower jaw bones, and nine teeth from the upper jaw.
There’s also a bunch of bones from the rest of the body including neck vertebrae, ribs, dorsal vertebrae or backbones, tail bones, both upper arm bones, bones from one of the forearms, part of the pelvis, and part of the hindlimb down to the ankle. Altogether a decent number of bones in the postcranial skeleton, some are shaped more like earlier dinosaurs, whereas others are more like typical theropods of that time period.
In 1994 Hammer and Hickerson briefly described Cryolophosaurus as a new species of dinosaur and made mention of a single pterosaur bone and fragments of a basal sauropodomorph. By the way, a basal sauropodomorph being an early relative of the ancestors to sauropods.
In the 1994 paper, they stated all the fossil material was from the Falla Formation. But based on a later paper of theirs published in 1999, plus the museum catalogue records, all their stuff is actually from the Hanson Formation. Just want to put that out there for hard-core fans that really want to know what the origin story of this theropod dinosaur.
Cryolophosaurus is from the Early Jurassic and remains to this day, one of the few dinosaur species known from Antarctica. The other being Glacialisaurus hammeri, the basal sauropodomorph I just mentioned, which was named and described more recently by Nathan Smith and Diego Pol in 2007.
There’s reports of a second Cryolophosaurus skeleton from a conference abstract, published by Nathan Smith and colleagues in 2013, but we’re still waiting to hear more on this 2nd specimen.
Getting back to the 1994 paper published by Hammer and Hickerson, I want to get into the etymology of Cryolophosaurus though, since it's just such a cool name. Etymology by the way, is just a fancy way of saying what the name means and how it got its name.
So the genus name, Cryolophosaurus: cryo means frozen, loph means "crest" and "saurus" means lizard. All together that name means the frozen crested lizard, and,
The species name of Cryolophosaurus, is "ellioti" and honours the contribution of David Elliot who found the first Cryolophosaurus.
I can't talk about the discovery of this fossil without taking a quick detour to discuss what it's like to conduct fieldwork in Antarctica.
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So, let's talk about Frozen Fieldwork
Fieldwork presents a range of challenges, but I'm pretty sure collecting fossils in Antarctica is equivalent to, I dunno playing legend of Zelda on hero mode.
You know, resources are scarce, if you're in what could be a dangerous situation you have to be really careful about how you do things, because if you're too reckless, then it's game over.
Obviously, not just anyone can waltz into Antarctica and grab whatever the hell they want: there's a lot to consider both in terms of the logistical side things, but also the environmental impact.
Personally, I've never been to Antarctica so I couldn't tell you what it's like, so I thought I should ask an expert. And who better to tell us what it’s like to do fieldwork in Antarctica, than Dr Nathan Smith.
Nathan Smith: This is Dr Nathan Smith, curator of the dinosaur institute at the Natural History Museum of Los Angeles County. Well I’ve been fortunate enough to participate in three expeditions to Antarctica in 2003/2004 field season, in the 2010/2011 field seasons that were based out of the Beardmore Glacier region, that’s when we were working on the Cryolophosaurus quarry, but also more recently in the winter of 2017/2018 when we worked out of the Shackleton Glacier region, in sediments older than these dinosaur-age sediments. We were mainly focused on the Permo-Triassic boundary, and collecting lots and lots of really great vertebrate fossils from the Early Triassic of that region from a number of different sites. And yeah, logistically, there are a lot of challenges, there’s a lot of planning and prep that has to go into getting down to Antactica in the first place. A lot of things have to go right, you know, not just with allocating the money but allocating the resources whether that’s helicopter and flight time. The housing challenges from moving people from various places throughout the world down to New Zealand, then down to McMurdo Station in the dormitories there, and then getting set up at a remote field camp. So it is a pretty big undertaking. I’d say those challenges are often greater than actually working on the side of the mountains down there or dealing with things like the weather which you kind of just have to plan a lot of downtime and extra time for. But there’s a lot of moving parts when it comes to doing fieldwork in Antarctica and so, being prepared for those and being flexible is one way that we deal with it. A fun comment that I like to reiterate from one of the staff members down there that does a lot of our camp planning and survival training for us once talked about the importance of putting together plans when we’re doing expeditions or when we’re doing day trips and things like that and he says “you have a plan, so you know what you’re departing from” because, nothing goes exactly according to plan but you still need that preparation to ensure you’re going to be safe and successful.
Adele: Even after months of planning, most trips don't get the green light.
One of the biggest reasons why research trips to Antarctica don't go ahead is because of safety concerns. Which is fair enough, because honestly, there is no sense in putting anyone in harm's way, even for science.
Another big factor is a lack of funding for proposed projects, but that's an issue not just with Antarctic research but science in general.
Other than that, the field area might be too far away from the nearest base, and there might not be enough room for the equipment needed on the supply ship. Again, it's not like there's a flight leaving every hour to Antarctica, everyone on that vessel needs to pull their weight and work together.
Which brings me to my next point: even though there are support staff like radio operators, plumbers, chopper pilots, doctors and electricians, the scientists on each team need to be properly trained and familiar with their own equipment.
So scientists are given first aid training, probably a bit more than just your basic first aid course but they also need to understand how to use radios to keep in contact with home base and 4 wheelers or quad bikes.
Help might be hours away, so it's good to know how to change a tyre or fix the motor on your vehicle before you set out to collect specimens.
I'm sure there's a bunch of other things to consider but all this to say, Antarctic fieldwork isn't for the faint hearted.
We've heard about the challenges of fieldwork in the frozen tundra, but let's go back in time and talk more about what Antarctica was like when Cryolophosaurus was alive.
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Before we get into form, function and family, let's zoom out and get into what Antarctica uses to be like.
It wasn’t just Cryolophosaurus running around during this time, as Dr Nathan Smith explains, we know of other creatures from this time period:
Nathan Smith: Well, we’re still only scratching the surface of what the Early Jurassic vertebrate fauna of Antarctica was like, because all of our information comes from that Cryolophosaurus quarry on the side of Mt Kirkpatrick, right? You see, the animals and fossils we’ve recovered from there. We know Cryolophosaurus is probably the top predator running around at that time, but we’ve also got evidence of a large long-necked sauropodomorph dinosaur, Glacialisaurus, as well as some smaller animals including the wing bone of a flying reptile, a pterosaur that’s from that site as well and also a tooth from a tritylodont so, not a mammal itself, but on the lineage leading towards mammals. And these tritylodonts are pretty ubiquitous in a lot of late Triassic and early Jurassic vertebrate faunas, so not too surprising to see it pop up there. We’ve also recovered more dinosaur material from My Kirkpatrick that hints at the existence of several new species of long-necked dinosaur, but it’s not going to be surprising to me at all, if we get more time down there and are able to explore more sites that we flesh out what the Early Jurassic world of Antarctica and its inhabitants looked like in even more detail.
Adele: When Cryolophosaurus was alive, Antarctica was not covered in ice, BUT it was still near the south pole at high latitudes. Which means that in summer the days are long, and in winter, the days are short.
As Antarctica was will within the polar circle during the early Jurassic, that means that Cryolophosaurus lived in an environment that flourished in spite of weeks if not months of continuous darkness.
Now, when we say polar today we typically think of it meaning a frozen environment. You know, South pole, north pole, polar express, you get the picture...
As soon as I say anything like that I bet you're thinking about snow, and ice. But that's not what it means. ‘Pole’ just refers to being high latitude and basically as far away from the equator as humanly possible.
Again, I feel like such a broken record but Antarctica has not always been a continent covered in ice. The reason why it's like that today is because of ocean currents, specifically the Antarctic Circumpolar Current which circles around Antarctica, and stops warm water from the equator getting down there.
The timing of the development of the Antarctic Circumpolar Current is a bit contentious, but as a rough estimate it was somewhere between 40 and 20 million years ago, after Antarctica fully separates from South America, which forms the Drake Passage.
But, like I said before, in the early Jurassic, 180 million years ago, Antarctica was covered in forests with mild temperatures but on the humid side.
We don't know a lot about this ancient ecosystem because fossils are hard to find, but compared with other theropod dinosaurs from the early Jurassic, Cryolophosaurus is no slouch, it's a pretty big animal.
And on that note, let's talk more about what this animal looked like.
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FORM
Broadly speaking, Cryolophosaurus is a bipedal theropod dinosaur, so a dinosaur walking around on its back two legs.
It's a medium sized theropod so about 5.5 to 6.5 metres long from nose to tail, which is equivalent to 18 to 21 feet.
Estimates on the weight range between 350 - 465 kilograms. If you're not familiar with the metric system that'd be about 772 - 1025 pounds.
Even by today's standards, this is a predator you wouldn't want to mess with.
It's even more impressive when you consider that most big dinosaurs are from the Cretaceous period.
I mentioned before what bones we have from Cryolophosaurus, and I don’t want to get to bogged down with details, but basically, some bones look more like earlier theropods. The femur, for example, looks a lot like Dilophosaurus, but I’ll leave it at that and come back to this idea when we talk about Family Grouping.
Like most theropods, Cryolophosaurus was carnivorous and mostly ate meat, but there were theropod dinosaurs that were plant powered. Definitely have plans to cover one of these in a future episode, but for all intents and purposes, Cryolophosaurus is like your typical theropod dinosaur.
But unlike most theropods, Cryolophosaurus has a distinct crest on its head, which is why it's sometimes referred to as the pompadour dinosaur or, simply Elvis.
The crest on the skull of Cryolophosaurus is a bony structure that sits just in front of the eyes and sticks upwards.
The crest is an extension of the nasal and lacrimal bones, two of the many bones that make up a dinosaur skull. The skull of a dinosaur is made up of roughly 60ish bones but, in many cases there's a left and right, say for example there's a left lacrimal and a right lacrimal. Hope that makes sense.
To look at it, the crest is noticeable but not super tall, and is defined by a series of vertical ridges. Honestly, it kind of looks like a crinkle cut potato chip or crisp.
That, combined with like, a slicked back hairdo. You can totally see why this dinosaur is nicknamed Elvis. The crest on the front of the skull is what makes this dinosaur so iconic, but there’s a bit controversy surrounding the purpose of this structure.
Nathan Smith: We’re not entirely sure what the crest of Cryolophosaurus would have been used for or what its function was. We can be pretty confident that it didn’t kind of play any combative role – right? It’s a pretty delicate crest and it’s probably not being used kind of bash skulls with any other dinosaurs. Our best guess is that it’s probably related to some kind of signaling role. Whether that’s kind of recognizing conspecifics, or as a sexually dimorphic display feature?
The problem, as it often is, with dinosaurs like Cryolophosaurus is that we don’t have enough specimens to test some of these hypotheses in more detail. But to date, that’s probably our best and it belongs with a group of dinosaurs that also has a lot of interesting crest shapes that are usually made up from some of the same bones. So it’s not like Cryolophosaurus is unique in that regard.
Adele: So when we say conspecifics, that’s just a word that means members of its own species. And as for a sexually dimorphic feature, I kinda hinted at this in the Ferrodraco episode but a sexually dimorphic feature is just a flex. It’s something pretty to look at, that an animal has, that it then uses to attract a mate. Hopefully I’ve done justice and been able to paint you a word picture and describe the Form of Cryolophosaurus. And, since we’re talking about what possible role the crest might have had, let’s now pivot and talk about Function.
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FUNCTION
Since I described the crest, or even just hearing the name ‘Cryolophosaurus’, you've probably been wondering, what’s with the crest? Like, why does it have it? What purpose does it serve?
OK, so one of the most obvious explanations for such a bizarre and distinct crest is to impress and attract a mate. This explanation pops up a LOT when studying really weird bones that seem to have no logical exclamation. It also comes up when we have enough fossils from a particular species and there seems to be 2 distinct forms in the adults.
Another possible explanation is that this structure evolved and helps with species recognition. This is important because, again, Cryolophosaurus looks like your basic, starter kit theropod.
It makes sense that this could lead to some very awkward situations where
Whatever the case, there seems to be a selective pressure on having a crest
Since we basically only have the one specimen of Cryolophosaurus, we can't really say for certain if its crest is for sexual display or species recognition, or something else entirely.
That said, it doesn't look like it is related to intraspecies combat, which is just a fancy way of saying fighting over mates. Why? Simply because it isn't that strong. That, and it's in a weird place. Plus there aren't signs of this crest breaking or healing, which is what we see in some horns and the tail clubs of some ankylosaurs.
So it seems that this feature isn’t particularly functional, and purely just for aesthetics. I’m not even mad, like I’m a total sucker for a guy with good hair and YES I realise this is the actual shape of the skull and not a hairstyle, but I think you’re picking up what I’m putting down.
Anyway, before things get any weirder, let's talk taxonomy and dissect the family history of Cryolophosaurus.
FAMILY
So when we zoom out, Cryolophosaurus belongs to a relatively obscure group of reptiles called the dinosaurs. You might have heard of them.
Dinosaurs have, historically been split into two major groups, the Ornithischia or "bird-hipped" dinosaurs, and the Saurischia or "lizard-hipped" dinosaurs. The names aren't really in-keeping with today's understanding of dinosaurs and the evolutionary history of this group.
What I mean by that, is modern day birds aren't descended from "bird-hipped" dinosaurs.
This is what happens when we come up with names and are stuck with them, despite the fact that our understanding of their evolution has changed a lot over the years.
Taxonomy is a mess, but bear with me, unlike other episodes, from here on out, this is going to be relatively painless and straightforward.
Ok so, theropod dinosaurs are probably the most famous dinosaurs. That's a hot take, I know, but keep in mind this is the group that includes Tyrannosaurus rex and Velociraptor. So you know, they're practically A-list celebrities as far as dead reptiles are concerned. Speaking of celebrities and controversy,
It's my civic duty to inform you that Velociraptor isn't as tall as you think, kinda like when guys lie about their height on their dating profiles. Jurassic Park grossly overestimated the size of Velociraptor, but that was based off the advice from the palaeontologist who was the main scientific consultant for the first phase of the franchise.
I’m sure I’ll end up doing an episode on velociraptor eventually, but yes, theropods are bipedal, they walk around on two legs and most (but not all) are carnivorous.
That's the broad group Cryolophosaurus belongs to, but if we zoom in, things get even more interesting.
So the first paper announcing the discovery of Crylophosaurus was published in 1994, but then, Hammer and Hickerson published a 2nd paper in 1996, describing Cryolophosaurus in a bit more detail. Off the top of my head the first paper was only a couple pages long, so the second has a lot of juicy details in it. The 1996 paper described Cryoplophosaurus as a type of allosauroid.
So that would place it within the superfamily, Allosauroidea, which is made up of four families: Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae.
If you’re a theropod superfan, you might have recognised some of those names I just mentioned, but more recent studies suggest Cryoplophosaurus is not an allosauroid. If anything, it’s more closely related to Dilophosaurus.
So in 2007 Dr Nathan Smith and colleagues published an in-depth description of Cryolophosaurus, including a phylogenetic analysis.
A phylogenetic analysis combines a lot of data on the shape and anatomy of the bones of various species, and uses that information to make a family tree.I like to think of phylogenetic analyses as being a bit like electricity, in that they follow the path of least resistance. Even though the same features can evolve independently in multiple groups, the simplest and most straightforward explanation is often true.
Describing the anatomy of a new species is one thing, but conducting a phylogenetic analysis and figuring out the evolutionary history of a group is arguably, even more important.
Getting back on track though, what Smith and colleagues discovered is that the next closest relative to Cryolophosaurus is a relatively famous dinosaur, Dilophosaurus.
Nathan Smith: The last work that we had published on Cryolophosaurus did suggest that it was the sister taxon or close relative of Dilophosaurus, from the Early Jurassic Kayenta Formation of the southwestern United States. Now there’s also work that posits Cryolophosaurus as the basal most, or earliest diverging member of the Tetanuran theropod group. And, in some ways, this isn’t a huge shift, we’re kind of talking about Cryolophosaurus kind of, moving up a couple pegs in the family tree of these meat-eating dinosaurs, one way or another. But as I eluded to, this is kind of an interesting time in theropod dinosaur evolution in the Early Jurassic we’re kind of transitioning from earlier forms, to the groups that are going to be taking over for the rest of the Mesozoic, so, regardless of where Cryolophosaurus ultimately falls out in that family tree, I think it’s going to be an important part of that story.
Adele: I'm not gonna get into Dilophosaurus and what Jurassic Park got wrong BUUUT if you want, I'll do an episode on it. Pleeaase ask me to do an episode on it, I have thoughts and would love an excuse to do more reading on this iconic dinosaur. That or a whole episode on what Jurassic Park stuffed up since that's the second time it's popped up during the course of today's episode.
Sorry I love tangents and am easily distracted by new ideas. I have what's known as, shiny object syndrome. Ummm, where was I... oh yeah. The results of this phylogenetic analysis.
Smith and colleagues resolved Cryolophosaurus and Dilophosaurus as sister taxa. So if you look up a picture of this phylogenetic tree, Dilophosaurus and Cryolophosaurus split off, or branch off from the same point.
Now, fossils of Dilophosaurus are known from Northern Arizona, in the US, which these days is pretty far away from Antarctica. During the early Jurassic, you could walk from the US to Antarctica because both landmasses were *callback* part of a much bigger supercontinent, Pangaea.
But, more recent analyses don't support this interpretation.
Dr Matt Carrano who I’ve had the pleasure of meeting before and is incredibly knowledgeable and super lovely, his 2012 study placed Cryolophosaurus within this group called Tetanura, and more closely related to Sinosaurus from the Early Jurassic of China. Again, this seems like a ridiculous distance from Antactica, but there weren’t any oceans between these localities, so species could disperse quite easily.
This interp was corroborated by Hendrickx and colleagues in 2015, their results also indicated a close relationship between and Cryolophosaurus and Sinosaurus, in which they were basal tetanurans.
But more recently, in the Dilophosaurus monograph published by Marsh and Rowe in 2020 indicated that Cryolophosaurus is a derived or specialised type, of neotheropod.
Monograph by the way, is like, the academic equivalent of a directors cut.
Despite the fact that there's some disagreement about what broader group Cryolophosaurus belongs to, there's a bit of a pattern going on. It looks like Cryolophosaurus is most closely related to Sinosaurus and after that, Dilophosaurus is a close cousin.
That said though, in a couple years time I’m sure there’ll be a new take on where Cryolophosaurus fits in the theropod family tree.
As Dr Nate Smith points out, it’s actually not too unexpected for the phylogenetic position of this enigmatic theropod to change over time.
Nathan Smith: We originally thought that Cryolophosaurus might have represented a tetanuran theropod dinosaur, so you can kind of think of that as higher up in the evolutionary tree more closely related to birds. But, the more and more we look at the anatomy of Cryolophosaurus, more things seem to… to sync up with what we were seeing in the other Early Jurassic form, Dilophosaurus. So it was a little surprising but it’s also a really unknown or poorly known period of evolutionary time for these dinosaurs. So, having things bop around in different positions on the family tree is not too surprising.
There you have it, sometimes we don’t have clear cut answers when it comes to figuring out how different species are related to one another, and sometimes we just need another puzzle piece to get a clearer picture of what’s going on, other times, we just need to look at old fossils with fresh eyes.
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MISC.
Last thing before we wrap up, let’s talk about where you can find out more about Cryolophosaurus IRL and online.
Cryolophosaurus and the other fossils that were collected during the field expeditions lead by William Hammer were on display at the Fryxell Geology Museum at Augustana College until Hammer retired in 2017. After that the fossils went to the Field Museum in Chicago, Illinois but they are currently part of travelling exhibit going around to museums across the US.
If you're interested in seeing the Antarctic fossil material, I'll link to the Field Museum website which has a fact sheet, tour schedule and exhibit overview.
Otherwise it looks like the Fryxell Geology Museum still has a replica of Cryolophosaurus on display near the entrance and is 22 feet from nose to tail which is equal to 6 and a half metres in length.
If you hallen to know of another Cryolophosaurus at a museum you’ve recently visited or you've seen the travelling exhibit on the Antarctic Dinosaurs you can tag me @PalsinPalaeo, I’d love to share your photos.
Speaking of the podcast’s Instagram, there’ll also be a photo of me with a little Cryolophosaurus yowie.
If you're new to the show, or live outside Australia, Yowie’s are a chocolate treat kind of like an Easter egg but on the inside there’s a capsule with a little toy inside. Well actually, there’s little plastic pieces which you assemble to then make a toy.
I loved them as a kid, still love them now in my late twenties. I just thought it was really cool that they encouraged kids to learn about animals and care about things like fish, insects and jellyfish, not just mammals and stuff like that.
In terms of pop culture, Cryolophosaurus isn’t as popular as its close cousin, Dilophosaurus, but it does features in an episode of Dinosaur Train.
For the uninitiated, Dinosaur Train is an animated show for kids'. The Cryolophosaurus voice actor sounds like Elvis Presley, linking back to the nickname given to this dinosaur and the crest on the front of the skull looking a bit like a pompadour.
If kids shows aren’t your thing, but you’re keen to hear more about Cryolophosaurus, definitely check out episode 68 of I Know Dino! I’ve done a couple interviews with Garret and Sabrina and they’re both super lovely and know tones about dinosaurs so there’s hundreds of episodes you can listen to.
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That’s it for today, thanks for chilling with me and hearing all about Antarctica and Cryolophosaurus. As always I hope you learned something, otherwise hopefully you found my stupid dad jokes mildly entertaining.
And if this is your first time listening to the show, thanks so much for giving it a go, I hope you’re hooked and keen to check out our other episodes.
Pals in Palaeo is a team effort- I literally couldn't do Pals in Palaeo on my own, so big thanks to one of my best friends César who produces the show. He also just peps me up and gets me psyched to do the podcast so very grateful to have him onboard and part of this project
You can check out his old-school film photos of wildlife on his Instagram @cesar_on_safari, there’s underscores between those 3 words but I'll put a link to it in the show notes.
Big thanks to Hello Kelly for our theme music and special thanks to Francy for all our other tunes and editting the show. Hey, if you like pop punk and pop rock, definitely check out Hello Kelly wherever you get your music, whether it be Spotify or Band Camp - in particular their latest record, Sweet Nostalgia. I seriously have to hold myself back and keep from adding the title track from that record to just about every playlist I put together it’s so good. When I first heard it from another podcast, Creative Pep Talk, I think I listened to it back to back for 10 minutes, I couldn't get enough of it.
Special thanks to Crumpet Club House and Jenny Zhao for the covert art for the podcast. I’ve said it before but I'll say it again, the cover art really sets the tone for the show and we’re trying to do so, thanks Amy and Jenny.
And yeah, lastly, if you want to keep up to date with me and the show, follow me on Instagram @palsinpalaeo, there’ll be a goofy photo of me with my mini Cryolophosaurus for you to check out
Until next time, if you’re driving, drive safe. Otherwise yeah have a good one and I’ll speak to you soon
References
First record of pterosaurs (Diapsida, Archosauromorpha, Pterosauria) in the Middle Jurassic of Madagascar
Hammer & Hickerson 1994:
‘A Crested Theropod Dinosaur from Antarctica’
https://www.science.org/doi/abs/10.1126/science.264.5160.828
Hammer & Hickerson 1996
‘Implications of an Early Jurassic vertebrate fauna from Antarctica’
Hammer & Hickerson 1999
‘Gondwana dinosaurs from the Jurassic of Antarctica’
Smith and colleagues 2007
‘Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution’
https://academic.oup.com/zoolinnean/article/151/2/377/2630870?login=false
Carrano et al. 2012
The phylogeny of Tetanurae (Dinosauria: Theropoda)
https://www.tandfonline.com/doi/abs/10.1080/14772019.2011.630927?journalCode=tjsp20
Hendrickx et al. 2015
‘An Overview of Non- Avian Theropod Discoveries and Classification’
Marsh and Rowe 2020
A comprehensive anatomical and phylogenetic evaluation of Dilophosaurus wetherilli (Dinosauria, Theropoda) with descriptions of new specimens from the Kayenta Formation of northern Arizona
Field Museum Resources and Info:
https://www.fieldmuseum.org/traveling-exhibitions/antarctic-dinosaurs
The Pals in Palaeo Cover Art
Jenny Zhao Design @jennyzdesign
Crumpet Club House@crumpetclubhouse
The Pals in Palaeo Theme Music
Hello Kelly @hellokellymusic
Podcast Editing
François "Francy" Goudreault
Podcast Producer/ Content Assistance
César Puechmarin