4. Glossopteris

Welcome to the wonderful world of palaeobotany with our first fossil plant, the 'tongue fern' Glossopteris. This episode we talk about gymnosperms and how this fossil helped piece together the theory of Plate Tectonics. Plus dancing dinosaur footprints for our Random Fossil Fact.

6/21/202325 min read

Today on the show we are exploring the wonderful world of palaeobotany, with the Permian-aged plant, Glossopteris! This episode we talk about gymnosperms, high latitude forests and piecing together the theory of plate tectonics.

Pals in Palaeo presents Glossopteris

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This is Pals in Palaeo, the show where we dig into the form, function and family history of your favourite fossils. I'm your host, paleontologist, science communicator and budding palaeobotanist, Adele Pentland

You can stay up to date with me and my terrible dad jokes on Instagram by following me on Instagram @palsinpalaeo.

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Pals in Palaeo acknowledges the Traditional Custodians of the land throughout Australia and their connections to land, sea and community. We pays our respects to the Elders past, present and emerging, and extends respect to all Aboriginal and Torres Strait Islander peoples today.

This episode was recorded on Koa country, in Winton, central western Queensland, and fossils of Glossopteris are known from sites across Australia, and overseas

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OK confession time: I kinda knew even before I started the podcast that I'd sort of gravitate towards doing episodes on topics familiar to me. So, lots of episodes on vertebrates and fossils from the Cretaceous and since we've done a couple vertebrates back to back I figured it was about damn time we have a break from animals with backbones and head to uncharted territory and dive into the "no bone zone".

That's a term I've appropriated from the Monterey Bay Aquarium in California, an incredible organisation with a legendary online presence that also works with researchers on cutting edge science.

So I want to plant a seed, literally, and focus on Glossopteris a fossil plant from the Permian, so the time period just before dinosaurs appeared in the Triassic.

Today's episode was also partly inspired by another podcast called Just The Zoo Of Us with Christian and Ellen Weatherford. Their show is a complete and utter delight, it's on extant species of animal so stuff that's still alive today and they don't just focus on charismatic megafauna but on their show they really try to strike a balance and talk about invertebrates and fish, animals that don't have the same PR as a keystone species.

So yeah, that's kind of why I wanted to cover a fossil plant from a time period that pre-dates the dinosaurs. I wanted to break free from this holding pattern of my own making and I figured it was also time to cover something that isn't uniquely Australian but found at other fossil localities elsewhere in the world.

I also wouldn't be a palaeontologist and I wouldn't be speaking to you today if I hadn't met a palaeobotanist and palynologist by the name of Dr Chris Mays. A palynologist by the way is someone who studies fossil spore and pollen grains.

Chris or Maysy taught me for second year sedimentology, so the soft rock course at Monash University and he also taught the palaeontology unit, which sigh this is gonna sound cliche but it literally changed my life.

The funny thing is, I didn't get the best marks in our palaeontology course. I don't think I even came 2nd overall, but I did get the best marks in our palarobotany prac course. Essentially it was a mini assignment, but the student who got the highest marks received a piece of petrified wood Chris had collected during fieldwork from the Chatham Islands.

The Chatham Islands by the way are a tiny set of islands off the coast of New Zealand, about 800km to the east of the South Island, which is almost 500 miles. So yeah, people I think I live in a remote area but the Chathams are next level.

Anyway, after that I really wanted to do palaeontology and wanted to get into honours and work on a project with Chris as my supervisor. And uh, yeah. The rest is history. In case you're wondering, I still have that piece of petrified wood by the way.

It's on my desk next to a bunch of other fossil themed knick knacks, including a Lego model of Ferrodraco I was given by a colleague.

Although I was inspired at uni to study palaeontology because of a palaeobotanist, I have zero experience when it comes to fossil plants. Of course I can pick when I've found a fossil plant in the field and know what's a good specimen for a museum collection, but that's about it.

So if you're a botanist and work on fossil plants, just turn the podcast off now... no, I'm kidding. That was a joke. Please though, go easy on me because I didn't study botany at uni, but don't turn off the podcast.

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Random Fossil Fact

Before we get into the weeds and discuss Glossopteris, first up is our Random Fossil Fact. Some palaeontology themed podcast bring you news, I bring you facts that have aged like fine wine. When the fossils have waited millions and millions of years to be discovered, what's another few years on top of that?

I also appropriated that saying, it's something Dr Tom Rich, Curator of Vertebrate Palaeontology at Museums Victoria says to me sometimes.

Anyway, today's Random Fossil Fact is the first fossil dancefloor from the journal Scientific Reports, and published by Martin G Lockley and colleagues in early 2016.

So a pretty prestigious journal lead and Lockley is badically THE expert when it comes to fossil tracks. Ichnology, the study of trace fossils, isn't just about footprints.

You can find all sorts of impressions, including resting impressions (or as I like to think of them, butt prints), feeding traces made from animals lunging into soft sediment or bird beaks probing into the ground and burrows.

Trace fossils also includes fossil feacs or coprolites, regurgitalites or fossil vomit, eggs... I'm probably missing some other ichnofossils but, just think of anything that indicates the presence of an organism. As opposed to a body fossil, which like the name suggests, is direct evidence because it's literally the body, or part of it.

Ichnofossils can reveal a lot about animal behaviour, for example, fossil footprints can be used to determine the speed and size of an animal. It's basically like forensic science, but prehistoric. Think, CSI Gondwana.

This paper is about more than just footprints, but something much more rare: dinosaurs dancing. The title of the paper sums it up better than I ever could, it's:

"Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs"

These authors discovered scoop mark and hummocks at four different sites across Colorado, specifically from the Dakota Sandstone which is late Albian-Cenomanian in age, making it about 100 million years old, give or take a few million years. The tracks are attributed to theropod dinosaurs, since they're the only animals walking around on two legs that can make something that size.

The scrape marks are all symmetrical but vary in shape: some are oval and others paired claw marks and the size differs too: they're anywhere between 0.75 to 2.00 m long and 0.50 to 1.25 m wide.

So that'd make the scrape marks between 2 and a half feet to 6 and a half feet long, and 1.6 feet to 4.1 feet wide. The depth also varies in size, some are pretty shallow at 5cm or 2 inches, but others are up to 25cm or a foot deep.

The scoops have clear claw marks at their deepest points, which could only be made my an animal dragging its claws along the ground.

As the name of the paper suggests, the main theory is that these were made by theropod dinosaurs doing a boot-scootin boogie to attract members of the opposite sex, like we see today in some species of modern day, ground nesting birds.

Which is super impressive because Untouched by the Veronica's didn't come out until 2007. Only joking, although I am a woman possessed when that song comes on, I've been known to bail out on a conversation and run, literally run to the dancefloor when I hear it. That, and Footloose. Can't help myself.

Lockley and colleagues came up with a few alternative explanations, suggesting these might be nests. But there's no evidence of eggshells and when you compare this site to fossil dinosaur nest sites, they vary a lot in size, depth and the scrape marks are a bit more random. By contrast, known dinosaur nest sites and fossil colonies are very evenly spaced and consistently shaped.

Alternatively, they might be the result of hungry or parched dinosaurs digging for food or water, or territorial scrape marks made on an attempt to ward off would-be adversaries. Again, it's not outside the realm of possibility, but based on the behaviour of modern day birds and their courtship rituals we observe these same scrape marks, albeit, on a smaller scale in specific areas or "display arenas".

In terms of figuring out which theropod made this tracks, that's another kettle of fish. It's almost impossible to figure out which animal made which track. We don't know which species made these, but yeah it was a large theropod so that's the same group T. rex belongs to.

If you want to find out more, and see photos of the scrape marks, I'll put a link to the article in the show notes, as well as another article summarising the paper from The Conversation.

From the dancefloor to the forest floor, let's go further back in time now and head into the Permian to talk about Glossopteris.

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It's time to talk about the form, function and family grouping of Glossopteris. This was a prolific fossil plant that thrived during the Permian period, with its earliest appearance in the fossil record dating back to about 299 million years ago.

It was found throughout the southern hemisphere during this period but went extinct during the end Permian mass extinction event, about 252 million years ago. The end Permian mass extinction event has also been given the fun nickname, 'The Great Dying'. Because it's the most intense mass extinction event to date, life was nearly completely wiped out.

It's estimated that between 90-95% of species went extinct at the end of the Permian, so if you ever get the chance to go back in time, highly recommend you skip that part of Earth history.

If you want to hear me talk more about this pivotal moment, please let me know I'm @palsinpalaeo on Instagram, if you request this as an episode topic it'll be at the top of the list because there's a lot of research on it, and it's not fair that the end Cretaceous mass extinction event gets so much attention when THIS ONE, this one's the biggie.

Let's talk about what the hell Glossopteris is because I think I've only referred to it as a plant up until this point. Broadly speaking, Glossopteris was a tall woody tree, so imagine something a bit like a conifer but with broad leaves instead of the thin needle-like leaves pine trees are known for.

Just to be clear, we're not completely sure what the full thing looked like, because that fossil is essentially a unicorn in that it is rare, and virtually non-existent.

As palaeontologist and palaeobotanist Dr Anne-Marie Tosolini, a senior lecturer at the University of Melbourne explains, piecing together different plant fossils can be quite difficult:

Anne-Marie: With plants, it’s a bit more of a puzzle to put the pieces of the plant back together, so it’s quite different to finding fossil animals. Often you’ll find the leaves quite separate from the roots or the tree trunks, or the fruiting bodies. So, roots, for example are given a completely different name to the leaves and they’re known as Vertebraria, um, they actually look a lot like a segmented vertebrae, so that’s why, it’s always been a challenge to work out what kinds of roots and branches and tree trunks matched with the leaves.

Adele: Sometimes you can find part of a tree stump in situ which is Latin for in life position. But the chances of a whole tree being found in situ, with leaves still attached after millions of years is pretty low. Still, the best fossils are the ones we have. We can learn a lot just by piecing everything together, and the fossil record is also full of surprises.

I was delighted to find out there's been fossil Glossopteris leaves still attached to their stems. The paper was published by Pigg and Taylor in the American Journal of Botany in 1993.

The fossil was discovered in a very remote location, the central Transantarctic Mountains in Antarctica.

Kind of makes sense that you'd find such an exceptional fossil in pristine and untouched wilderness, although you'd be surprised what turns up even nowadays with building works and stuff like that. I'll put a link to that paper in the shownotes, but unfortunately that one isn't in open access. If you have a subscription to that journal though or you're affiliated with a university you might be able to still get access to it. Um, I try not to do this too often but yeah, this paper's pretty special so I just had to mention it.

Unlike most of the other fossils we've talked about on the podcast, Glossopteris is known from multiple specimens and it comes in a few different shapes and sizes. If you just search for it in Google you'll probably see photos of fossil leaf mats, which looks how it sounds, they're basically a slabs of rock with leaves fossilised on the surface.

Now, you might be wondering, how do palaeontologists and in this case, palaeobotanists tell the difference between different species?

It's based on a combination of shape, size and the structure of the veins, or the lines that branch off from the centre or the 'midrib' as it's known. Glossopteris leaves are longer than they are wide and tear-drop shaped. The leaves vary a bit in size, ranging between 2 to 30 cm so less than an inch to about a foot long.

Anne-Marie: Leaves of Glossopteris are very beautiful, and they look quite modern. So when students look at the Glossopteris fossil leaves, they often ask, “are these modern, flowering trees?” or some ask, “are these eucalypts?”. So, it’s remarkable their anastomosing veins are really, very advanced for their time. They were probably very good at photosynthesizing but they were over 100 million years before any flowers appear.

Adele: As far as leaves go, they can get to a pretty decent size. If you've seen fossils on display at a museum or university, especially those in the southern hemisphere, chances are you might’ve seen these IRL. Pretty sure we used to have some in the hallway of the geology building at my old uni.

If you want to get technical, the genus Glossopteris, only applies to the leaves. So even though there are probably fossil cones from this same species, in the literature, they're referred to the broader family of Glossopteridaceae. Again, it might be because things have already been named and then later it was found that they actually belong to the same species but I'm just spitballing here. I don't know. I don't make the rules.

Those Glossopteridaceae cones I mentioned before are analogous to pine cones on conifer trees and the cones of cycads. So imagine something pretty tough, maybe a bit on the woody or chewy side, so not something you would want to eat.

The other form Glossopteris fossils comes in, for better or worse, is coal. Intense pressure and temperature conditions has transformed the forests of the Permian into a fuel source exploited across the southern continents.

Anne-Marie: Another really interesting thing about Glossopteris is that it’s key in our understanding of plant evolution. It was a significant element in swamp flora that formed important Permian coal measures right across the southern hemisphere and these have been used as critical energy resources for over 100 years, but, helps us understand the evolution of what’s known as gymnosperms, before flowers had even evolved.

Adele: Most of the Permian-aged coal deposits across what used to be Gondwana are made up of gymnosperms like Glossopteris. And there were tonnes of them.

If you think of peat, which is essentially decaying plant matter, spelt P-E-A-T, you would need 10 m of peat to make a 1 m layer of coal, and when you think about how much coal there is, there would have been millions and millions of Glossopteris trees throughout earth history.

Out of all the fossils we've talked about on the show so far, this one has probably affected the most lives, based on the economic impact alone.

The bulk of these coal deposits were made from what used to be trees, with Glossopteris growing to estimated heights of 30m which is almost 100 feet tall.

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As far as I can tell there isn't anything else I need to mention regarding the physical form of this fossil so let's talk about how this influenced how this organism functioned.

Pretty self-explanatory but like modern plants today Glossopteris used its leaves for photosynthesis, converting water and carbon dioxide from the atmosphere into sugars and oxygen.

It's also assumed that Glossopteris was deciduous, based on the sheer volume of fossil leaves that are found together. If you look closely there's really nothing wrong with these leaves for the most part, they're not sickly looking or anything like that, so why get rid of them?

Well, like deciduous trees today this is typically triggered by a change in the seasons and more common in trees at mid to high latitudes, so getting further away from the equator. The reason for that, is the winter months are hard, so hard, that holding onto their leaves during this period is more of a liability than anything else.

So it's just easier to get rid of all of them, and start again when the growing conditions are more favourable.

This interp is backed up by the patterns we see in the growth rings of Glossopteris trees. So you can count the rings to figure out how old the tree is, but also look at the thickness of each ring to see what else is going on.

What I mean by that, is, the thicker the ring, the better the growth season. Glossopteris grew the best during the spring and summer season but growth just about ground to a halt in autumn and winter.

Glossopteris trees grew to massive heights, because they're vascular plants but I'll get to that in a minute when we talk about the evolutionary history of this species. But basically the fact that they had secondary lignin or bark on the outside, which essentially formed the scaffolding for them to grow and helped them get ridiculously tall, again maxxing out at 30m or almost 100 feet.

Growing tall is an important adaptation that allows plants to compete with others in their environment for sunlight, and once they get to a certain size, they're less likely to be eaten by herbivores. Bark is the botanical equivalent of growing a tough skin, and again offers protection from predation from insects and fungal pathogens and stuff like that.

The Glossopteris forests (say that 5 times fast) grew at mid to high latitudes, so closer to the geographic poles, and not at the equator. Presumably the trees resembled a conifer in shape, so imagine a Christmas tree which is tapered at the top.

It grows to that specific shape to get as much of that low angle light as possible. If you've visited anywhere near the Arctic, or live in Northern Europe you'll know what I'm talking about with low angle light. The sun just sits a bit lower in the sky, compared to the equator, and that also changes with the seasons.

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Family Grouping

We've talked about Form, we've talked about Function, now let's dive into the Family Grouping of Glossopteris.

Broadly speaking, Glossopteris is a vascular plant, meaning that it transports sugars and other nutrients around using a series of tubes. Chances are if you see a plant today and it doesn't look like it's 95% water and can grow over 30cm or a foot, it's probably a vascular plant. Off the top of my head, the things that aren't vascular plants are algae, mosses, hornworts and liverworts.

Glossopteris is a type of Gymnosperm, which in Latin literally means, "naked seed". In fact, during the permian period, angiosperms or the flowering plants which are the most common land plants on Earth today hadn’t even evolved yet. As Anne-Marie explains, Glossopteris also differs from modern conifers, even though both are types of gymnosperms:

Anne-Marie: Glossopteris are key to understanding plant evolution and during the Permian period, which is known as the Palaeozoic era, there were only gymnosperms around, there were no flowers. And so, they were quite different to the conifers we see today, and they were probably closer to other seed plants known as seed ferns like cycads are probably the only remaining plant surviving today from that whole lineage. Ginkgo actually is another example actually

Adele: Definitely want to also cover Ginkgo in a future palaeo plant episode even though yes, there's still one species alive today.
Unlike most other plants today, gymnosperms don't have flowers, and they don't have fruit. Like I said, you could probably eat a Glossopteris cone, but why would you?

It probably wouldn't taste very good and wouldn't be super nutritious. Remember, it's important not to get caught up in doing something to the point where you forget to ask yourself, 'is this a good idea?'

Glossopteris was a perennial plant, meaning that they lived for more than a year. Which makes sense, right? Gotta live for more than a year to get to those big sizes.

I couldn't find an exact number of different species but there's over 70 species within the Glossopteris genus. Just to zoom out, Glossopteris belongs to the Family Glossopteridaceae, and was described waaaay back in 1828. In terms of human history and our understanding of palaeontology, we've had a long time to get familiar with Glossopteris, and in fact, this fossil was fundamental to our understanding of geologic processes.

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I teased at the very start of the episode that the theory of plate tectonics was proven to be true, with help from Glossopteris. As palaeontologists started to unearth more and more fossils it became apparent that there specific patterns and certain similarities between some regions in that they had the exact same types of fossils, despite the fact that they are now separated by oceans.

So for a while there, it was a bit of a mystery as to how and why Glossopteris was found in Australia, New Zealand, Antarctica, South America, Africa and India. These continents of course were once connected and together, formed the southern supercontinent Gondwana, which we mentioned in the episode on Anomalocaris.

Anne-Marie: lossopteris was one of the key fossils that was discovered on South America and Africa, showing that they used to be joined together, as well as Australia and India, even though India is no longer in the southern hemisphere. So the remaining piece of that jigsaw puzzle was to see if Glossopteris was preserved as a fossil on Antarctica, the last frontier.

Some beautifully preserved fossils have been found from Antarctica, preserved in 3D, in silica, and this has helped to build a whole picture of Glossopteris trees.

Adele: It just goes to show that fossils can also help build our understanding of Earth through time, and palaeontological discoveries were key to our understanding of Plate Tectonics.

This theory was originally introduced as the theory of continental drift and championed by meteorologist Alfred Wegener in 1912. When he first presented this idea, it didn't have a lot of traction, and basically wasn't accepted during his lifetime.

Part of this is because Wegener was missing a mechanism driving continental drift. He had correctly identified what was happening, but was struggling to explain how it was happening. The scientific community at the time was also reluctant to accept this theory, because Wegener was an outsider: he wasn't a geologist, he was meteorologist.

This was during a time when science was "a gentleman's pursuit" so I'll put it this way, back in those days I wouldn't have had a thriving career as a palaeontologist, because for one thing, I'm a woman, and secondly, I'm half Asian. It was very elitist back then and we obviously still have a way to go but yeah, scientists can be snobs sometimes.

Wegener was an outsider, but his unique perspective was his biggest strength and asset, ultimately helping him to see the world as it is. There's a lesson to be learned here: the more we embrace different backgrounds and ways of thinking, the better we can tackle complex problems.

Wegener's theory was widely accepted, or as I like to think of it, became geological canon in the 1960s, with the discovery of magnetic anomalies on the ocean floor, which they found accidentally. During that time, during the Cold War, they were trying to focus on finding submarines but instead accidentally learned about the geology of the ocean floor.

Through this inadvertent detective work, they found the missing mechanism to Wegener's theory: subduction and spreading zones on the seafloor. The spark notes summary is that ocean crust gets heavy at a certain age and sinks, partly pushed by the formation of new ocean crust in other spots.

I'll leave it at that, this is a palaeontology podcast. For more on subduction zones, see our sister podcast, gals in geology. That's... not an actual podcast but bloody hell I wish it was. If someone wants to start a gals in geology podcast, go for it.

Getting back to our plant boy, fossils of Glossopteris, as well as the freshwater reptile Mesosaurus and the bulky dicynodont Lystrosaurus, which in the words of Steve Brussate, the last one's built like a quarterback linesman. The distribution of these three fossil organisms is really difficult to explain, based on their current distribution.

But when you push the continents they're found on, together and in the right order, it makes perfect sense. There's a very good reason why the eastern coast of South America looks like the western coast of Africa. They were once connected but split apart during the breakup of Gondwana.

So if anyone tries to tell you "palaeontology is basically stamp collecting", set them straight. It's, so much more than that. Understanding ancient life can tell us a lot about how our Earth has changed over million of years, and give us insight into how it'll continue to change in the future.

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We've talked about the form, function and family grouping of Glossopteris, and taken a quick, unexpected detour to discuss large-scale geologic processes through the theory of plate tectonics and this is normally the part of the episode where I mention where you can find out more about the fossil covered in the episode, list the documentaries its featured in, etc. etc.

As you can probably work out, I don't have a name for this section of the show. Uh, I was thinking of calling Fandom, but that doesn't sound right either, I don't know if I'm using that word right, but yeah, if you have any ideas, let me know, @palsinpalaeo on Instagram because I don't know what to do.

Anyway, fossil plants and plants in general don't quite get the same airplay and attention that vertebrates get. I'm certain that if there's a doco that features ancient life from the Permian, there'll be Glossopteris in the background.

Maybe even getting eaten by a herbivore. If you know of an example, please share your wisdom with me, you can tag me on Instagram @palsinpalaeo and I'll try to catch us up in a future episode. Otherwise you can tag me in any palaeontology or science memes.

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Before we wrap up with thank yous and some final recommendations, I wanted to take a second here to make a couple announcements:

First off, I’m.. absolutely blown away by the response the podcast has gotten, and wanted to say thanks to everyone who’s listened to the podcast and a special thank you to everyone who’s left a rating or review, or shared the podcast through social media. You’re the best.

I really didn’t know what to expect when I started this. I mean, I figured that my friends who knew I was working on this were going to tune in, but I thought maybe, to begin with, there’d be like 20 or so people who knew me IRL and that’d be it.

But yeah, if you’ve sent me a really sweet message just know that I’ve saved it as a screenshot in my phone, in a folder called, “knocked down 7 times, back up 8” and as you can probably tell, when I’m having a really tough time, I go back through those messages.

The other announcements I had is on Koolasuchus which we covered in episode 2. So if you missed that one, Koolasuchus cleelandi is a massive extinct amphibian and the state fossil emblem for Victoria, which is a state in Australia. Now, the science surrounding that fossil is still solid, I didn't stuff up there, BUT I did muck up some of the extra facts at the end of the episode. So I wanted to take a second to acknowledge that, I'm far from perfect and I just wanted to highlight that science is self-correcting.

What I mean by that, is that as new information comes to light, it's OK for our view and understanding of things to change and evolve and grow. At its core, this is how scientific research works, and I'm going to always do my best to bring you accurate information that's up to date.

This sounds super dramatic now, but it's really nothing major, I promise! Most of what I said is true, but at the end of the episode on Koolasuchus, I was talking about pop culture stuff, mentioned Yowies and was saying how I struggled to find stuff at the Melbourne Museum gift shop. Yowies by the way are like a kinder surprise, it's a chocolate treat and there's a toy inside with assembly instructions and information

BUT, there is no Koolasuchus Yowie. There is a temnospondyl yowie, but it's based on Siderops from the Jurassic of Queensland. So a different state, and a completely different time period with millions of years betweenthem. Now, I'll probably end up doing an episode on Siderops at some point but yes, they are different species.

As for the Melbourne Museum gift shop, as it turns out, they do have some cool stuff featuring Koolasuchus! Shout out to Jack O’Connor and Jessica Campbell for letting me know what I was missing out on.

To be honest, when I was at Melbourne Museum in January, I was basically running around like a headless chook. If I saw this merch, it wasn’t really on my radar because I was completely distracted. Professor Kliti Grice who I mentioned in the Koolasuchus episode was there on a research visit, and I really wanted to make a good impression.

Anyway, for anyone who's interested, there's Koolasuchus enamel pins and even a birthday card in the Melbourne Museum gift shop.

Jessica also mentioned that the new Gondwana Garden at Melbourne Museum has replica jaws of Koolasuchus that visitors can touch. They're pretty hard to miss since they're bright blue. Like I said in Ep 2 the real Koolasuchus holotype jaws are on display, and speaking of Pals in Palaeo alumni, there's also an Anomalocaris model, and fossilised mouthparts on display too! They're just around the corner from Koolasuchus.

Jack O’Connor had some notes on the anatomy of Koolasuchus as well as merch. Honestly, I'll probably get Jack on the podcast at some point to talk about the work they did during their honours on Zygomaturus which is a giant marsupial and close cousin of Diprotodon which I seem to mention every second episode. AND we’ll probably expand on the form and function of Koolasuchus because they’ve made an amazing 3D sculpt of Koolasuchus too and honestly know more about this ancient amphibian than I do. By the way, you can check out that 3D model on their Instagram which is @jackocdesign, all one word, I’ll pop that up in the shownotes, but in terms of tangible, real world Koolasuchus merch

There’s a Koolasuchus figurine made by CollectA and it SUPER detailed. Not only does the head have some of that ornamentation that we talked about in episode 2, but that also extends to the pectoral girdle, so the clavicles or collarbones of Koolasuchus. Again reflecting the real world morphology of this fossil.

And, there’s even tiny hooked denticles on the inside of the mouth of this figurine.

That’s something I didn’t touch on in the podcast, but in this case, denticles are toothlike-projections. Denticles can also refer to the tiny serrations we see on teeth, like in theropod dinosaurs.

Getting back to Koolasuchus though, these denticles are on the palate, or the roof of the mouth, and because they essentially act as a bunch of tiny hooks, this would have made it difficult for prey to escape once it grabbed them with its massive wheelie bin shaped head. Again, arent you glad you don't live in the Cretaceous?

Anyway, my final footnote for the Koolasuchus episode is related to Function, rather than form. Remember when I was trying to temnospondyls swimming and compared them to crocs? Can we play some flashback music?

“So it makes sense that it would have a powerful tail adapted for swimming and propelling itself through water”

As it turns out, this we now have fossil evidence for this behavior. So less than a week after the Koolasuchus episode dropped, a new paper came out, entitled:

“Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour” and that was published by David Groenewald and colleagues in the journal Plos One. Plus One is an open access journal so all of their stuff is free and I’ll also link to that paper in the shownotes, but basically, using 3D surface scanning techniques which we mentioned in our bonus episode on VAMP, they studied trace fossils, including fossil swim traces and body impressions.

Based on this evidence, the legs were tucked up near the sides and the tail pushed the animal forward, through the water, similar to how modern crocs swim today.

Now I should point out that these fossils are from the Permian, and these fossils are attributed to rhinesuchid temnospondyls. BUT Koolasuchus is a
member of the Superfamily Brachyopoidea, and is in the Family Chigutisauridae. So while it’s likely that Koolasuchus was similar in its swimming behavior, Groenewald and colleagues were in fact, looking at a different branch of the temnospondyl family tree.

Still it’s pretty cool to see more research on these loveable weirdos, and find some fresh research to back up what was an educated guess on my part.

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Last thing before we wrap up, I wanted to point you in the right direction and give you some podcasts recommendations if you're chasing more botany and plant science content.

If you want to learn more about gymnosperms, highly recommend Episode 155 of the Common Descent Podcast with special guest paleobotanist Dr Aly Baumgartner.

Love episodes with Aly, especially the 2021 Halloween series Common Descent did on speculative evolution where they tried to come up with ways of evolving monster plants. Think I requested we listen to that specifically in the car the night Harry broke his second collarbone and I drove him to the hospital.

If you want me to do more plant podcast episodes let me know, I'm @palsinpalaeo on Instagram, otherwise the Planthropology Podcast with Dr Vikram Baliga will scratch your itch.

If you're not sure where to start, might I recommend my favourite episode of Planthropology, which is number 74 with Ellen Weatherford who I also mentioned this episode. Again, Ellen and her husband Christian Weatherford are the hosts of the animal review podcast, Just the Zoo of Us.

Think that there's been a bit of cross over between the two shows but again my favourite Planthropology podcast episode was when Vikram and Ellen talked about grass-type Pokémon and the real world inspiration behind their designs. The banter between the two of them is delightful, it's worth listening to for that in itself.

Thanks for listening, I hope today's episode was enlightening, informative and just weird enough to keep your attention.

Don't forget you can get in touch with me online, don't be afraid to reach out and say hi, especially if you want to talk about fossils and palaeontology, I'm always up for a yarn. You can DM me on Instagram @palsinpalaeo

Thank you to Francy for editing the show, and a big thank you to the band Hello Kelly for our freaking amazing theme music, PSA they also made a song about Steve Harrington AKA the best character from Stranger Things.

You can listen to that song on their Instagram, their handle is @HelloKellyMusic and check out their latest album Sweet Nostalgia which is oon their website, on Spotify and anywhere you get good music

Shout out to Dr Chris Mays for starting me on this path, his enthusiasm for all things palaeontology and teaching in general is infectious. It had a profound impact on me, and there were others in my cohort that have gone on to do postgraduate research and yeah, it's amazing what impact a great teacher can have.

Finally, thanks to my buddy César for producing the show and keeping me on track. If you want to hear from him, checkout his podcast Death By Birding but beware there are swear words

Thanks again for listening, if this is the first time listening to the show I hope you enjoyed it and thanks so much for giving it a go. Pals in Palaeo will be back soon with a fresh episode soon but until then, just keep digging


Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs


Mysterious footprint fossils point to dancing dinosaur mating ritual

Anatomically preserved Glossopteris stems with attached leaves from the central Transantarctic Mountains, Antarctica

Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour


Pals in Palaeo on Instagram


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

Podcast Production/ Content Assistance

César Peuchmarin