7. Arenaerpeton with Lachlan Hart

Adele chats with Australian Museum palaeontologist Lachlan Hart about the new Triassic temnospondyl species he named, Arenaerpeton supinatus! A fossil discovered in a sandstone block by a retired chicken farmer, that went on display as part of the Dinosaur World Tour in 1997. 

We discuss the shocking secret world of these extinct animals, including cannibalism in amphbians, horns, tusks, and toxins. Just when you thought it was safe to go back in the water... 

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Transcript

Today on the show we are talking about the new ancient amphibian species Arenaerpeton supinatus. This is fresh science, this is hot off the press. The paper describing this new fossil friend came out TODAY. Honestly, it doesn't get much better than this

Pals in Palaeo presents Arenaerpeton with Lachlan Hart

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I'd like to acknowledge the Traditional Custodians of the land throughout Australia, in particular the Darkinjung People as well as the Gadigal People of the Eora Nation. I recognise First Nations People as the original scientists, engineers and technologists of this land and recognise their connections to land, sky, water and community. Pals in Palaeo pays our respects to the Elders past, present and emerging, and extends that respect to all Aboriginal and Torres Strait Islander peoples today.

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Today we are once again talking temnospondyls. And I know what you're thinking "Adele, we've already heard about temnospondyls, these weird ancient amphibians" and yeah I realise Koolasuchus comes up in every other episode, you're probably sick to death of hearing me talk about them but hear me out! OK so I originally wanted my next amphibian to be Beelzebufo from the Cretaceous of Madagascar. You might be familiar with the so-called devil frog or demon toad if you've seen the 2nd season of Prehistoric Planet. Anyway I was at Palaeo Down Under 3, at the Early Career casual hang out session and it was at a brewery, having a great time and our guest on today's episode Lachlan Hart mentioned he'd listened to the episode on Koolasuchus. I also just want to give a shout out to Isabella Donato another awesome palaeo at the University of Adelaide who listens to the show. It really means a lot to me whenever someone says they listen to the show, let alone other palaeos doing kickass science. But yeah! Lachlan and I were chatting, he said a bunch of nice things about what he thought of the Koolasuchus episode, as well as something that needs fixing up, but more on that later, and he also wanted to see if I was keen to have him on to talk about a new temnospondyl he's been working on from the Triassic. And like, how could I say no?

Not quite the same as someone offering to fully fund a dinosaur dig for an extra 3 years in exchange for a helicopter ride and signing off on a bit of paperwork, but still!

So yeah, that's a peak behind the curtain and glimpse into the chaotic behind the scenes of making the podcast. I'm really good at making plans but terrible at following through but the upside of talking about another temnospondyl is that we get to cover these ancient amphibians in a little bit more detail. Including the fact that some temnospondyls had tusks, horns and there's recorded evidence of cannibalism. On top of that, it's a fossil with a surprising origin story, and you know I'm a sucker for that.

I hope your sufficiently psyched up for this killer interview with Lachlan but before we get into all that, first things first, it's time for the random fossil fact.

If you want to keep up to date with the latest and greatest dinosaur research, check out I Know Dino with Garret and Sabrina and if recent advancements in evolutionary biology is more your thing, tune into Common Descent. Meanwhile if Pals in Palaeo was a radio station, we'd be playing golden oldies. To me finding a paper published 10+ years ago on something kind of niche that's still really cool and relevant to today... I dunno it's kind of like going to the op shop and you find an amazing book for like $5. And it's a first edition. Something about the thrill of the chase and combing through old stuff in search of treasure... it's very similar to being out on a dinosaur dig and searching for fossils. You're on the lookout for these long lost relics, sometimes you walk away empty handed and don't find a single thing, other times you hit the jackpot.

Anyway I'm sure you didn't tune into this episode to hear me talk about the parallels between palaeontology and second hand stores, you're here for facts on fossils.

Today's Random Fossil Fact is something pulled from my conversation with Lachlan and it's on temnospondyl cannibalism. There's a few recorded cases of this behavior, but today we're going to zoom in to talk about the extinct amphibian Apateon gracilis. The evidence is pretty damning by the way, there's literally bones of a small Apateon in the gut of a larger individual.

The paper describing this was published by Florian Witzmann in 2009, in the journal "Fossil Record", and as always I'll chuck a link to that in the shownotes, that one's free to read too.

Witzmann noted that many modern amphibians eat members of their own species, sometimes it's kind of common, other times it's brought on by a change in the seasons but normally, it's the eggs and larval stages that get picked on. Which makes sense right? They're the smallest, and the easiest to catch.

Just to provide a bit of background to Apateon, it's a type of temnospondyl from the Permian of Germany and it belongs to a group called the branchiosaurids, and the adults grew as large as 15 cm from head to tail, so if you're not familiar with the metric system, that's half a foot long. So they're not as big as the new Triassic temnospondyl we'll here about later on in this episode. They're just, little.

Some members of this group, the branchiosaurids are so well preserved that you can see what's going on with their gills, and it looks like their gills were set up to trap plankton swimming in the water and eat them during their teenage phase.

The adults though were eating fish and yeah, other branchiosaurids, so this includes other species, and conspecifics too. Conspecifics is just a fancy word that means, members of their own species, or the same taxa.

And like a lot of amphibians alive today, this particular species, Apateon went through metamorphosis. So the eggs would have been laid in water, there would have been an aquatic larval stage or "tadpole phase" and then the adults lived on land. Pretty cool to think that this iconic life cycle has been going on for millions and millions of years.

So yeah, in some groups of temnospondyls, their bodies went through some big changes throughout their life cycle, and as their bodies changed, they also switched up what they were eating as well.

Here's the kicker though, even after metamorphosis, in the adults of Apateon, the teeth are on the small side, they're kind of delicate and packed close together so they're more suited for eating plankton and filter feeding. So yeah it's kind of surprising to find evidence of cannibalism in that particular species.

The author of the paper Florian Witzmann noted that cannibalism in amphibians sometimes gets triggered by changes in the environment, the big one being when a water body starts to dry out. This not only pushes whatever's living in that water together, but there's less food available too so all of a sudden, friends or family become food.

There's also been instances where these bone beds are discovered, and they’re just jam packed full of amphibians that all died at the same time. Obviously very tragic, but they do make spectacular fossils...

But yeah I heard Lachlan mention that during our conversation, just very casually that temnospondyls were cannibals, or at least some where and I had to learn more. That's not even the weirdest thing about them, like, not even close. I learned heaps when I was chatting with Lachlan and I think you will too. Let's go back in time and explore some Triassic temnospondyls and learn about Australia's newest fossil amphibian.

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Adele: This is Pals in Palaeo, the show where we talk to the experts about some of the fresh and exciting discoveries being made in palaeontology. For today's episode, I have a really special guests, fellow PhD candidate, Lachlan Hart. How are ya? 

Lachlan: Yeah, I'm good. How are you? Thanks for having me. 

Adele: No worries. Thank you so much for making time. I chaotically decided at the last minute that recording today as a spur of the moment thing would be an absolutely great idea. And I'm so lucky that you decided to accept the invitation. You're currently a PhD candidate at the University of New South Wales. 
 
 Lachlan: That's right. Yeah at UNSW and jointly at the Australian Museum as well. 
 
 Adele: Yep. So you're supervised by Dr. Matt McCurry. 
 
 Lachlan: am that's pretty much it. I've actually been really blessed because of COVID and related things. I've had a few changes to my supervisory panel over my PhD tenure. But Matt has been the one constant through the whole thing, which is really good, because he's the one that knows the most about my project. 
 
 Adele: Yeah. And before we hit record we were chatting before… So did he already have this project sort of lined up? We're here to talk about a very special new temnospondyl, an ancient amphibian. But you've also worked on fossil crocs before.
 
 Lachlan: So I was finishing off my master's thesis at UNE. And I was coming towards the end of that, and also thinking was going to do next. And so I'm originally from Sydney, when I was living up in Armidale, to do the masters and I thought I'd really like to move back to Sydney to be with family. And so I contacted Matt at the museum, and I asked if he had any PhD kind of projects in mind that the student could do. And yeah, he said, “Well, what you want to work on?” Like, well, “I've worked on crocs before I'd like to continue working on Mesozoic stuff. If it's possible, but it doesn't have to be crocs. He said, “Well, we don't have that much croc material. But what we do have is a really great temnospondyl material.” I’m like, “Hmmm, that sounds interesting.”

I hadn't really worked much on temnospondyls before. I knew what they were but I hadn't worked intensely on them, so that was kind of how it came about. It was a bit of a challenge to get my head around all the taxonomy and the literature of another brand new group, after just spending three years learning all about ancient crocodiles. And yeah, and one of the projects that Matt had in mind, in fact, the very first project that Matt had in mind for me to work on was this new fossil that we're going to talk about today.
 
 Adele: Yeah, I should say for anyone who hasn't listened to the episode on Koolasuchus, temnospondyls are ancient amphibians. Their body plan is kind of similar to a croc? Would that be fair to say?

Lachlan: Yeah. So I've heard them described is a bit of a mix between a crocodile and giant salamander? Their postcranial skeleton definitely looks more croc-ish. So the variation that we see in temnospondyls is in their skulls. So that's where we see the most difference. So there are some that have heads that kind of look like crocodiles? So animals like Paracyclotosaurus and Eryops had very long skulls, like crocodiles. And then there's other ones like Koolasuchus that had more parabolic, brevirostrine skulls like a giant salamander. 
 
Adele: So yeah, sort of quadrupedal. So four legs rolled out and long tails. But then the heads are quite distinct from species to species. But there are a few things that unite them. One being ornamentation in the skull. So instead of just smooth bone surface, it's a crazy sort of pattern. 
 
Lachlan: Yeah, kind of wrinkly looking. It's very distinct. Once you see a couple of them, it's very easy to kind of pick out temnospondyl skull bone. Because of that very wrinkly looking texture. They also have a sensory canals that kind of go deep into the roof of the skull, which is kind of cool, which they probably used for sensing stuff when they're swimming around in the water. 
 
Adele: So able to detect electric currents and like the movements of the muscles of other animals around them? 
 
Lachlan: Yeah, potentially kind of analogous to what sharks can do today. They've got that umm… That… 
 
Adele: Ampullae of Lorenzini? 
 
Lachlan: That one, yeah. The Ampullae of Lorenzini, the like the sixth sense of sharks have. So it's kind of analogous to, that or maybe even more like something that I think a platypus has something similar as well, where they have these… It's like sensory perception when they're in the water because platypuses? Platypi? Platy… I don’t know… They’re fairly blind and so they use these different sensory things to kind of feel their way around when they're foraging for food in the water. So yeah, temnospondyls, perhaps use these in a very similar way, although I think their eyesight may have been put a bit better than a platypus. 

Adele: Yeah, I suppose with temnospondyls as well. Their eyes aren't sort of facing forward in line with their jaws. Are they kind of like looking upwards at the water above them a lot of the time?
 
 Lachlan: Yeah, so again, this is another variation in between species of temnospondyls. Some have their eyes really close to the front of their snout. Some have them really close to the back of their head. Some have them kind of at the midline. Some the eyes have kind of migrated down towards the sides. So a bit like what you might see in a dinosaur with the eyes on the sides, but yeah, with a lot of them, the eyes are kind of placed on the top of their head.
 
 So like modern amphibians, like frogs and salamanders do. Some salamanders – not all. Maybe frogs is a better analogy. But they have almost frogs have the eyes kind of plopped right on the top of their heads. And then they can look up when they're in the water and they can just kind of poke the head up a bit and their eyes are kind of poking out. There's evidence by looking at temnospondyl skulls, that there were quite a lot of muscle attachments to the bottom of the eyes. So they were probably able to kind of pull their eyes but down a fair bit into their skulls.
 
 Adele: Is that to help with eating? Or not.
 
 Lachlan: I don't know, maybe it was more of a protection thing. But yeah, by them had like quite a large muscle attachment point for the eyestalk which is interesting.
 
 Adele: Yeah, that's absolutely wild and something that they don't really think about in terms of looking at a fossil skull. “Oh, I wonder how far it can reject its eyeballs.” But I say that because I work on pterosaurs and it's just not a consideration.
 
 Lachlan: Yeah, so apparently into their mouth.
 
 Adele: That's what I've heard with frogs. That fact still haunts me today.
 
 Lachlan: Yeah, so they were very, very weird animals.
 
 Adele: Yeah. And I feel like Australia as well, because the fossil record here is more extensive than it is in other places around the world. It just stands out more as being even weirder.
 
 Lachlan: Yeah. So Australia is really weird because these models were actually around before the dinosaurs. They arose during the Carboniferous period, but they really had their hey-day in most places in the world except Australia during the Permian period. And at the end of the period, as a lot of people know that’s when we had the biggest mass extinction that ever occurred in Earth's history. Over 90% of living things died or something during “The Great Dying”, but temnospondyls survived. They're one of the few vertebrate groups that actually survived that end Permian mass extinction event. Prior to that there's hardly any record of them at all in Australia. And then after the Permian extinction events, so the next period is the Triassic. In the Triassic, they're going bananas. You’re tripping over temnospondyls in Australia in the Triassic In fact, we don't find much else in Australian but temnospondyls in Triassic terrestrial strata which is very odd.
 
 Adele: I feel like Australia will sometimes just be late to catch onto a trend starting back with a temnospondyls. So Australia's kind of noteworthy because well Siderops was found in I'm gonna say the 60s? Not sure if that's right?

Lachlan: 1983 it was finally described, I think the fossils, I think the fossils would’ve been found before that though. Because it's a complete skeleton, especially back, then it took quite a long time to work on describing things because they didn't have all the fancy computer technology and high quality photographs and 3D stuff that we have today, a lot more old fashioned palaeontology.

Adele: Probably would have had to write their manuscripts on a typewriter and then mail it to the editor.

Lachlan: Yeah, and the level of detail in the illustrations in those old manuscripts, it blows my mind. Like, I'm a very bad artist. I can't draw very well. And so when I see the drawings that these palaeontologists did with these papers that I'm reading, Like wow. I couldn't ever draw anything this accurate to this amount of detail.

Adele: Yeah, no, I feel exactly the same way. That level of I guess understanding of the anatomy as well. But some of them look better than photos to be honest.

Lachlan: Yeah, they are.

Adele: So Siderops is from the Jurassic of Queensland, which was really weird because temnospondyls were thought to have been basically completely wiped out at that point.

Lachlan: Yes. So even though they survived the end Permian extinction, it was believed that they probably died out at the end of the Triassic. There was no evidence of them at all surviving the end Triassic extinction, which was still an extinction event. Just not quite as major as the end Permian one. But then they found Siderops in not even the earliest Jurassic sediments in Queensland. It's kind of Early–Middle Jurassic sediments in Queensland, which is just insane. There's essentially a near complete skeleton, and they thought, “Well, this has to be the last one”. This really weird one just came and survived into the Jurassic. And then not long after that. It was like here's a challenge to the rest of the world. And they actually found other temnospondyl fossils that were even younger than Siderops in Southeast Asia. Then they thought, “Well, okay, these had to be the last ones!”

And then as your listeners would know, Koolasuchus popped up and finding Koolasuchus in Early Cretaceous sediments in Victoria. I read somewhere I think it was Tom Rich that compared it to… It'd be almost the same as finding a Tyrannosaurus rex alive today because there's literally a 60 million year age gap between Siderops and Koolasuchus which is almost the same age gap between T rex and us. So that's what puts it into a bit more perspective.

Adele: I had never heard it described that way but that is… It's hurting my head a little bit and I love it but oh my gosh. So in Australia, we've got Triassic, Jurassic, Cretaceous temnospondyls. They've been found in Victoria, as we said, with Koolasuchus. In Queensland with Siderops. Before you started your PhD. How much did we know about temnospondyls in New South Wales?

Lachlan: Not too much compared to what we know about especially the Queensland temnospondyls because that's where we find the majority of our Triassic temnospondyl fossils particularly in a place called The Crater, which is kind of I'm gonna say kind of central west Queensland but I might be wrong. Your Queensland listeners will probably correctly but yes, it’s the Arcadia Formation.

Adele: Everyone has a different definition of what Central Queensland and what's western Queensland, let's not get into it.

Lachlan: Queensland! Somewhere in the outback in Queensland is this really great place where they found lots of temnospondyls. And the only temnospondyls that we know of from Victoria is Koolasuchus. There's a couple known from Western Australia as well, but as far as New South Wales stuff goes, there was one juvenile temnospondyl fossil found from the Central Coast. There's one isolated jaw from an enormous one called Bulgosuchus, which was found at Long Reef, which is kind of on the coast, not far from the centre of Sydney. And then there was this other one, which I mentioned a little while ago called Paracyclotosaurus, which was an enormous crocodile shaped temnospondyl that was found in the early 1900s. And then the holotype of that was shipped off to the British Museum of Natural History. Because that's what they used to do back then. So we don't even have it, but we have the cast of it.

Adele: Do they still have it?

Lachlan: Yep they still got it.

Adele: Okay, I know what with pterosaur fossils. Sometimes stuff was sent out in the mail, and then no one knows where it is, it was lost in the post.

Lachlan: Yeah, they couldn't have posted this because the holotype was these massive ironstone nodules that they found in a brick pit in St. Peter's, which is one of the suburbs of Sydney. You can still see it on display at the British Museum of Natural History actually. They cast out the skeleton out of like the natural mould that was inside those ironstone nodules, and they put on display. It's this massive crocodile looking temnospondyl. So that's pretty much it as far as temnospondyl taxa from New South Wales goes and nothing kind of linking it to the temnospondyls that persisted right through to the end. So Siderops and Koolasuchus are both members of a family called Chigutisaurs, and we had nothing in New South Wales that was kind of linking the whole family history of these late survivors together. 
 
Adele: So attempts to try and throw together the temnospondyls, the Australian record in phylogenetic analyses… Because there wasn't many fossils, was it difficult? 
 
Lachlan: Not particularly difficult, because we still have a good record of this particular family that we're talking about from other places in Gondwana. So there's a number of species known from both South America and India, that kind of at that point in time kind of tie the whole story together. But it was still weird that we didn't have anything known from New South Wales. 
 
Adele: I really do want to talk about this new temnospondyl, which you presented at Palaeo Down Under 3. It was amazing. I had to follow you presenting as well, which was kind of nerve wracking, because it was like, “Ah! Oh my god. How am I gonna top this?” It was such a good presentation. 
 
Lachlan: Thank you. 
 
Adele: But you also published on an isolated tooth from Talbragar. Is that right? 
 
Lachlan: That's right. Yeah. So that was that was the very first paper I got out of my PhD. And that was part of tying this whole story together. So the fossil fish beds of Talbragar are a really known fossil site in New South Wales. They're one of the few Jurassic deposits that we have. But previously, all they pulled out of there, as far as vertebrates go, were fish, and that's why they're called in the fossil fish beds. And this site has been excavated for over 130 years. And this is by museum people and fossickers and amateur collectors. Yeah. So they were pretty certain that they weren't going to find anything else besides fish, and insects and plants there. And then a few years ago, on a routine fossil trip out there, one of the dig team found this little tooth and it caught the eye of the others there. And they thought, “Oh, that doesn't really look like any of the fish teeth that we have seen from the fish that we know from Talbragar”. And Matt collected it and put it to the museum collection. And then I started my PhD and he said, “Hey, you want to work on this? I don't think it's a fish tooth. Can we have a look and see what it is.” So we got it micro CT scanned. 
 
It's tiny. The actual tooth is about the size of half your pinky nail. Yeah, so we micro CT-ed it. And it turns out that it had this characteristic enamel pattern that we see in temnospondyls. So there's an enamel pattern called plicidentine, which is the unfolding of the external enamel of the tooth that gives temnospondyls what is quite characteristic of them. In fact, it's what gave them their original taxonomic name, because they used to be called labyrinthodonts, referring to the labyrinthine in-folding in this enamel. Yeah, so I saw this in these micro CT images at different slices as well in this one little tooth and I’m like, “that’s a temnospondyl tooth.” 
 
So we found temnospondyl tooth in these Jurassic sediments, that people didn't think there was any tetrapods in at all. So yeah, it was a cool little tooth and cool little story that kind of fit really neatly within my whole PhD, which is very lucky. 
 
Adele: Yeah. It's crazy to think that after 130 years of excavations by so many different people, a site can still have its secrets. 
 
Lachlan: Yeah. And like it was a bit funny trying to work out how this one… and it’s not even an entire tooth, it’s the crown of the tooth. And so this one little broken tooth, how did it even get there in the first place? 
 
Adele: Because temnospondyls don’t shed their teeth… Do they? 
 
Lachlan: Yeah, they do. They do, actually. 
 
Adele: Okay, I thought I remembered something about the teeth aren't in sockets, but I could also be misremembering. 
 
Lachlan: They're not technically in sockets, but they have like tooth growth that’s kind of alternating? So every time they have a set of teeth that's in their jaw, they have a second set that's kind of pushing through, and the original set fall out. 
 
Adele: Yeah, it's still replacing old teeth with new teeth. It's just more like a conveyor belt but it's still ensuring that there aren't big gaps in the teeth because prey might then be able to escape if there's a large enough gap. That makes sense. But then do they also have denticles on the roof of the mouth? 
 
Lachlan: Yeah, some do. And some also have really large fangs in the roof of their mouth or tusks, sometimes they call them and some of these could be as big as your thumb.
 
Adele: Why? 
 
Lachlan: Catching fish, maybe? I don’t know. Some even had them like in their lower jaws. So they had these big tusks pointing upwards, that grew so large in some species that when they closed their mouth, the only place that these upward facing tusks ago was through their nostrils when they shut their mouth. 
 
Adele: That seems really counterproductive. 
 
Lachlan: Yeah, so they're closing their mouth. And yeah. That was something I learned when I first learned about temnospondyls. So they had these really unusual teeth. 
 
Adele: I knew they were weird, but it's good to talk to you because you actually know your stuff. But my gosh, like they just get weirder and weirder. Anyway, I guess that's part of their mystery and the charm. 
 
Lachlan: Yeah, they’re, they’re very strange. They're an extinct group that does have living relatives in living amphibians. But what we see in living amphibians is so far removed from what temnospondyls were, that it's hard to make inferences based on what we see in living amphibians. And it's hard to find appropriate analogues for what we're looking at. For example, if you're looking at theropods, and you want to look at theropod feet, you can go and look at an emu or a cassowaries feet because they're still theropod feet. But the modern frogs and salamanders don't have tusks. 
 
Adele: Honestly, tusk was not on my bingo card of words to pop up in today's interview.

Lachlan: Haha. Well, you learned something today! 
 
 Adele: Yep. Okay, let's just get into it. This new temnospondyl, it was discovered by accident? 
 
 Lachlan: Yes. 
 
 Adele: And it's sort of the finale for your PhD. 
 
 Lachlan: Yeah. So as I said, it was like the first project I gotten is basically the last thing I'm working on before I submit my PhD. So it took quite a long time for me to work on this. And I wasn't the first person to look at it either. When it was first discovered in 1997, a whole bunch of scientists have looked at it since then, and just haven't had the time to work on it and describe it fully. And so I was lucky enough to get to work on it was discovered by accident. But yeah, a man who was a retired chicken farmer bought a bunch of rocks from the local quarry at Kincumber on the central coast of New South Wales, to build a retaining wall at his house. 
 
 And they turned up one of these rocks and hosed off the mud, and this nearly complete skeleton of an amphibian was just sitting there. 
 
 Adele: That's absolutely wild. So… sort of touched on before, like other people had tried to work on it, did more preparation need to be done to the specimen before the science could happen? Or…
 
 Lachlan: Yeah, apparently, the original block that it was in was over a tonne. So very heavy, but the fossil wasn't spread across the entire face of that block. And so it was cut down with a rock saw, it's still very heavy, it still weighs 300 kilos. I've never tried to lift it myself. And I don't want to because I don't want to get a hernia, but yet still very heavy, very dense sandstone, and very hard to manually prep. So I tried to manually prepare the fossil when I first started working on it. And if you look at the photos of the fossil, you can see these white lines. This kind of white halo around some of the fossil where I've tried to attack it with the prep tool, but it just wouldn't prep. 
 
 Adele: You've made your mark. 
 
 Lachlan: I made my mark on it. Yeah, it just wouldn't prep. I'm not a sedimentologist or anything like that. But I think it has something to do with maybe the density? 
 
 Adele: It sounds like that could be a chemical cement binding the sand grains together. But yeah, in terms of it not separating nicely from the bone, there could be a density or a lack of density contrast between the fossil and the surrounding sandstone. That's my guess anyway, I'm not a sedimentologist either. 
 
 Lachlan: Yeah, that was my educated guess. I spoke to a few other people who knew more about it than I did, and they kind of agreed with me. And that was actually confirmed even more so. So after the manual prep was a bit of a fail, we decided, well, let's try to get this the X-ray-ed. So we took it to a covert X-ray facility. We got special permission that would never be granted to anybody again. And we use high powered X-ray scanners normally reserved for the scanning of shipping cargo to see if we can penetrate the fossil with those x ray beams and see the details. So one thing I didn't mention is that the fossil is lying on its back. 
 
 Adele: So you’re kind of looking at it on its belly, and then it's on its back. So you can't see its back.
 
 Lachlan: Yeah, or the top of its head or its eyes or any of these sutures of the skull, which most vertebrate palaeontologists will tell you that they're some of the most important features in the skull of any vertebrate for diagnostic reasons. Yeah, so we took it to this X ray facility and we attempted to get X ray scans but just like we had with the manual prep, very little definition between the bone and the matrix that was surrounding it. So I was kind of left to take some good photos of it and draw some lines around what I thought the bones were and describe it from there.

Adele: So if the prepped block is now 300 kilos, which would be about 660 pounds, how big is the fossil within that?

Lachlan: From the nose of the fossil or the edge of the snout to what's preserved it’s about 94 centimetres. It's missing its tail, so it would have been over a metre long when it was complete.

Adele: So it's about 3.3 feet long. So not a massive animal, but still pretty sizable.

Lachlan: Yeah. I mean, there are Chinese giant salamanders that are kind of in the same size range as far as length goes. But one really cool thing about this one is that because it's on its back, we can see its ribs, so we can kind of see how thick or heavy set that was. And just by looking at the ribs, we can see there's a much more robust animal than a giant salamander. And the other thing that we can kind of look at and make inferences about how thick it was is that we have, it's actually the outlines of soft tissue.

Adele: That's absolutely mind-blowing. I had never considered that you could get soft tissue preservation in sandstone. I don't know why, but for some reason, I just thought it was a limestone concretion thing.
 
 

Lachlan: Yeah. I mean, again, I don't know the geochemistry behind it. I just know that I look at the fossil and I see this nice shadowy black outline around the ribs and there's a little bit in the head and there's a little bit kind of around one of the hands that we have preserved. And yeah, that's all soft tissue. And so we can kind of have a look at it and say, well, this is the extent of the ribs and this is the extent of the soft tissue, which extends quite a fair way away from the ribs, which can kind of tell us a couple of things. One thing that can tell us is that that's maybe how fat the animal was in real life. Maybe he was just kind of plump. Or it could tell us that perhaps after the animal died, the corpse was subject to bloating, like a lot of things do when they die. And so because it bloated, that would have stretched out its skin and its fatty tissues surrounding the body a little bit further.

Adele: Yeah, so I should also say, so the soft tissue is sort of like a black kind of gunky colour, but the bone, I'm guessing, is like a whitish colour?
 
 

Lachlan: Yeah, most of it. Some of the bone is, especially in the head, some of the bone is not preserved as clearly as the ribs and some of the vertebrae are, which again made trying to work out what bones were what in the skull very difficult. It's also crushed, the skull is quite crushed. Again, making description a bit of a challenge, Adele *laughing*

Adele: It's funny, sometimes I'll be working with one isolated bone trying to figure out where it fits in an animal's body and kind of be wishing I had something more complete to work with. But the more material you have, I guess, the more the pressure's on to try and do something with everything that you have. And when the best x-ray scanner in the country doesn't work, well… Yeah, you just kind of have to do what you can with the fossil that you have. 
 
 Lachlan: Yeah, and especially with this one. So when it was first discovered it caused a bit of a media frenzy. It was in about 20 different newspapers around the world, the New South Wales Premier calling it a national treasure. It generated a lot of public interest. They even put it on display at something called the Dinosaur World Tour, which was this Canadian touring dinosaur exhibit that just happened to be in Sydney at the start of 1997 when they found the fossil. And so yeah, they put it on display there and I actually went there as a young kid with my parents and my little brother. So I would have seen that fossil and then more than 20 years later, I ended up working on it for my PhD.

Adele: I forgot to ask you this at the start because we immediately just started talking temnospondyls. But when you were younger, did you want to be a palaeontologist when you grew up?
 
 

Lachlan: I did. It crossed my mind and out of my mouth every day of my life when I was a young kid. So I was obsessed with dinosaurs from an early age. I'm a pre-Jurassic Park baby, and so I was obsessed with dinosaurs before Jurassic Park, and then it came out, and then everyone was like, “Oh, yeah! We like dinosaurs too!” So then I wasn't so weird. 
 
 Yeah, I wanted to be a palaeontologist, and then I finished primary school, went into high school, and found out that being a palaeontologist and liking dinosaurs and stuff like that wasn't a very cool thing to do. And so I kind of pursued other avenues of interest like music and stuff like that for a little while. And when I finished high school I went into teaching. So I did a teaching degree and I was a primary school teacher for over a decade. 
 
 Adele: So then what lured you back into the world of palaeontology? 
 
 Lachlan: I don't know exactly what the trigger was that made me think, you know what, I really should go back and chase my original dreams and live what I wanted to live. And maybe I was there in the classroom every day telling my students, “Whatever you want to do, you can achieve it!” And I'm standing there thinking, “Well, when I was your age, I wanted to do something that's not what I'm doing now”. Then I made the decision to start studying again. Initially, I did it part-time while I was still teaching, and then eventually I had to give up being in the classroom altogether to pursue research and palaeo as a more full-time pursuit.
 
 Adele: At that stage, was that when you started doing your Master's at University of New England?
 
 Lachlan: I was still teaching in the classroom for a little while, while I was doing my Master's. I was doing that kind of part-time and doing my Master's part-time and then gave up fully once I started the PhD.
 
 Adele: So you study full-time and get a stipend and all those good things?
 
 Lachlan: All those good things. I also work part-time at the Australian Museum and I teach in the School of Education at UNE as well. 
 
 Adele: Awesome. What's your role with the Australian Museum?
 
 Lachlan: I'm a technical officer in palaeontology and the project that I'm on is actually working on something that's completely removed from my PhD. Which is good because that means it doesn't affect my stipend. And I'm working on the McGraths flat deposit, which is a Miocene lagerstätte that was recently discovered not too far from where the Talbragar site is actually.
 
 Adele: Yeah. Did that come out this year sometime?
 
 Lachlan: I think it was maybe the very start of last year, the original site description paper? And there's been a few more papers leading on from that describing the new species of fossil insects and spiders and stuff that have come from there.

Adele: Oh yeah, the spiders are spectacular. I'm an arachnophobe. I freak out whenever I see like a big hairy spider. I can look at a redback and be like, “Hmmm, don't touch”. But yeah, even I have to admit, they're stunning fossils.
 
 

Lachlan: Yeah. So I'm pretty lucky that that's the job I get to do when I'm not thinking about temnospondyls. I get to sort out fossil insects and go and smash rocks and find new ones inside rocks.
 
 Adele: Yeah, that's awesome. Getting back to temnospondyls, we've been talking about this incredible new specimen in sandstone from the Kincumber Quarry. How does it stack up compared to some of the other temnos from Australia? Do you think it's a new species?
 
 Lachlan: Yes, it is a new species. Am I allowed to name my new species right now or do we…?
 
 Adele: Yeah, I reckon go for it.
 
 

Lachlan: Okay, so we're going to call it a new genus and new species actually. So the genus name is Arenaerpeton.
 
Adele: As of this recording, the paper isn't out yet, but I will be good. I'll wait and do everything right and wait until embargo. I feel like I get to play journalist. Like this is very exciting for me to have an exclusive, not an exclusive, but...

Lachlan: This is the first time I'm talking about it, so it's fantastic. Yeah, so we're calling it “Arenaerpeton”, which means “sand creeper”, referring to the sandstone block in which it's found. And the species name is “supinatus”, which means “lying on its back”, because as I explained, the fossil's lying on its back. So yeah, Arenaerpeton supinatus is going to be the official name for the Kincumber Retaining Wall Amphibian.

Adele: The Kincumber Retaining Wall Amphibian is also like a great name.

Lachlan: It is.

Adele: But Arenaerpeton, it's fitting that such a spectacular fossil that generated so much hype when it was initially found will finally have a scientific name. Have its moment in the sun as it were and it'll be put on public display as well?

Lachlan: Yeah, so the Australian Museum have had it in their collection since 1997 and now that it's finally been described and named. Towards the end of this year, around December-ish, they're saying that it's going to go on to display in the museum so people can come and have a look at it and yeah, just marvel at this amazing fossil that I got to work with.

Adele: And you're obviously going to see it when it's on display. You're going to get a photo with it.

Lachlan: Absolutely, I'll get a photo with it. Just like I got a photo with my family walking to the Dinosaur World Tour all those years ago, I'll recreate the photo with my little brother and we'll do it again. It's going to be a special moment for me. I went to the Australian Museum all the time as a child growing up in Sydney and to have a fossil that I actually named and described to be on display there is just something else.

Adele: Yeah, it's really cool when you get to have that moment of knowing you've made your mark in palaeontology and I guess being part of inspiring the next generation of palaeontologists as well. Who knows, there could be kids that see the fossil and 20, 30 years time maybe there will be an X-ray scanmer and that will be powerful enough to see the dorsal surface. You know, there's a whole world of possibilities.

Lachlan: Yeah, and they'll be able to describe it better than I ever did. And that's great. Because science is self-correcting and that's what we want to do. You know, every time we put something forward, it's a hypothesis. I'm hypothesising that this is the new species and this is what the anatomical details that I can see, this is what they tell us. When we can see more of what's hidden in that rock, then I'm sure they'll learn more about this pretty amazing animal.

Adele: I'm sure there will also be people who study soft tissue preservation that will be clamouring to work on this as well. You mentioned that there's a little bit of soft tissue around the torso area as well as the hand. I'm pretty sure I know the answer to this from your talk at PDU3, but does it have webbed hands?

Lachlan: So we can't see that much, unfortunately.

Adele: No!!

Lachlan: I like to think that most temnospondyls did have webbed hands because...

Adele: Makes sense.

Lachlan: Especially the ones that lived from the Triassic onwards spent most of their time in the water. The ones that lived prior to that, during the Permian, animals like Eryops, spent more time on the land, but most post-Permian temnospondyls were more obligately aquatic.

Adele: So if they're spending most of their time in water, I'm guessing a lot of amphibians they would reproduce in the water. Does that mean they would also be hunting in the water as well, you reckon?
 
 Lachlan: Yeah. So the really cool artist reconstruction of Arenaerpeton that we got done has it chasing a common fish in the Sydney Basin called Cleithrolepis. So that's probably what most temnospondyls are doing, hunting fish or other small prey. There's evidence of cannibalism in temnospondyls, eating the larval forms of even the same species, basically hunting down anything that was smaller than them in the water.

Adele: That's very on-brand for amphibians. I think, I can't remember what species it is off the top of my head, but I know there’s one species of frog, and the dads have their babies in their mouth. But if they want to mate with another female, they just swallow their babies to get them out of the way. It's absolutely brutal.

Lachlan: That's gnarly. That's great. Yeah, amphibians are, they're not going to win any parent of the year awards. Let's put it that way.

Adele: So the new paper describing Arenaerpeton, I'm assuming your PhD supervisor, Matt McCurry, is a co-author on the paper. Is there anyone else who helped you with it?

Lachlan: Yeah, so the project was given to me by Matt and he helped me through the whole process and so yeah, definitely thanks to Matt for that. But also we had Bryan Gee, who is not based in Australia, he's based in North America, who is pretty much like one of the world experts in temnospondyls, who was really helpful in helping work out some of those finer details of the anatomy and the phylogeny. And also Pat Smith from the Australian Museum as well. He doesn't work on vertebrates, but now I'm teasing him saying he's actually a vertebrate palaeontologist now because he's got a paper coming out in the Journal of Vertebrate Paleontology. Pat's a trilobite guy. loves his trilobite, but he's also a very good biostratigrapher and he's got quite a good brain for geology. And so Pat was really helpful. Just kind of working out what was going on geologically with the Arenaerpeton specimen.
 
Adele: Yeah, so it was discovered accidentally. In terms of actually figuring out, specifically where it came from, it wasn't really an easy task.
 
Lachlan: So they don't know exactly where in the quarry the rock came from. And they never found the other half, the counterpart to the fossil. So they can only kind of guess, but from what Patrick could see and he explained to me when we looked at the fossil is that there's a fair bit of information in it that kind of can tell us a little bit more about how the fossil was deposited. Of course there's quartz sand in it because that's sandstone, but there's alternating intervals of carbonised fossil plant material in it and that combined with like no real cross-bedding in the fossil, low grain size, sharper grain angles, all that type of stuff kind of tells us it's probably a low energy environment. It's not traveling down a really fast stream. 

Adele: Yeah, that makes a lot of sense because even though the skull is crushed, the animal is in life position or in situ and the vertebrae, the bones that make up the spine, they're just one after the other.
 
 Lachlan: Yeah, and the ribs. So the vertebrae and the ribs and part of one of the big bones of the chest called the interclavicle, they're all as they would have been in life. Anyway, that all came from the brain of Patrick Smith. He's pretty good with that type of stuff. I also give a shout out to our paleo artist. We mentioned the paleo art before. So our artist's name is José Vitor Silva. He's a Brazilian palaeo artist. He's done some art for me before. The last two pieces of art that I had commissioned, Vitor did those ones as well for me, which were when I described-
 
 Adele: The first one being Isisfordia molnari?

Lachlan: Yeah, the Isisfordia molnari. So he did that one.

Adele: That's the croc.

Lachlan: Yeah, that's the croc. Other one was he did a piece of art for... Last paper I put out, we investigated body mass estimation techniques in temnospondyls. And so he did this really cool artwork of two fat temnospondyls sitting on a balanced scale, because we were kind of examining the mass. So yeah, he's a really great artist and easy to work with and yeah. Hopefully his artist's reconstruction will go up next to the fossil in the museum when it goes on display as well, which would be fantastic.

Adele: You'd be crazy not to. It's stunning and I've said this before in other conversations with friends, nothing makes fossils come to life like good palaeoart.

Lachlan: Yeah, that's true. And one really clever thing about this piece of art is that when you see it, it shows the underside of the animal. And as you remember from the earlier discussion, the fossil is only preserved from the belly up. And so instead of getting about what the top of the animal looked like, if it had horns or what its dermal ornamentation might have looked like.

Adele: Oh my God, I forgot they had horns.

Lachlan: Oh yeah, they had horns. But we don't know if Arenaerpeton had horns. So because of that, this really clever piece of palaeoart, because we just see it from the belly up as we see the fossil. So we're not making any inferences that aren't there.

Adele: We had a little bit of a conversation at Palaeo Down Under 3, because you actually listened to the Koolasuchus episode. And when you said that, part of me was like, “Yay!”, but also, “Oh no!”, because I'm not an expert in temnospondyls. You said something to the effect that Koolasuchus probably wasn't eating dinosaurs.

Lachlan: Yeah, I mean. It definitely wasn't ambushing dinosaurs, in my opinion. There's a lot of evidence to suggest that Koolasuchus and other broad-headed temnospondyls, ones that had heads that are very similar in shape to modern giant salamanders, were actually suction feeding their prey. Because that's what modern giant salamanders do.
 
Adele: So I don't think we've touched on suction feeding on the podcast before, but my understanding is that by opening the mouth really quickly, that then creates a vacuum and it kind of sucks food towards it. Does that kind of sound right?
 
Lachlan: Yeah, that's pretty much it. So it's been observed in some temnospondyls that we have really good mandible and cranial fossils. That, from what we can see from the muscle attachments is that they didn't swing their jaws downwards like most other animals do when they open their mouth. They actually swing their cranium upwards. And so that's why a lot of us that work on temnospondyls refer to them as having heads like toilet seats, because if you imagine how a toilet seat opens...

Adele: Oh! I thought it was a shape thing!
 
 Lachlan: It's also a shape thing, but it's also the swinging of the lid.
 
 Adele: I never made that connection!
 
 Lachlan: Because a lot of them, their heads were quite thin comparatively, so not very deep skull.
 
 Adele: Kind of pancake-y.
 
 Lachlan: Yeah, kind of pancake-y. Like a big broad toilet seat. And so it's lifting up the toilet seat from the top and leaving the mandible underneath, which had, like I said, those gnarly fangs and tusks and stuff ready to catch anything that went in there. And yeah, because it's lifting up this really broad sheet of bone and skull upwards, that's creating that vacuum that's sucking things into its mouth as it's eating.
 
 Adele: That's absolutely nuts and wild. If we go back in a time machine, we don't have to worry about Arenaerpeton or Koolasuchus potentially eating us because the physics just wouldn't work. 
 
Lachlan: Yeah, look, I'd probably still go swimming with one. Those teeth are still kind of scary. 
 
Adele: I bet they would have some sort of mouth bacteria. 
 
Lachlan: Oh yeah, for sure. And probably be kind of slimy and... 
 
Adele: They could be toxic as well. 
 
Lachlan: It's in their family tree, right? So they potentially could have had venom glands or anything like that. Like who knows? That type of stuff doesn't fossilise. 
 
Adele: You've got soft tissue there. That's your next project. 
 
Lachlan: Yeah. But regardless, I wouldn't go swimming around if there's three and a half metre long amphibian with the head the size of a garbage bin lid. It just doesn't sound like a place I'd want to be. They can tell you that they're placid and that they're not going to bite you, but you still don't want to stick your foot in the water to find out, do you?
 
Adele: Anything with a mouth can bite you, essentially.
 
Lachlan: Yeah, and look, just because they were feeding by suction doesn't mean that they couldn't bite things the normal way either. Just have like a little nibble, see if it tastes any good. Although I don't think they're too picky.

Adele: In terms of taxonomy, Arenaerpeton, it seems that it's actually not that closely related to Siderops, which to me was surprising because… Even though at this point in time Australia is still part of the big supercontinent Gondwana, I'm still kind of assuming, “Oh, well, the ones in New South Wales, surely they would be closely related to the ones in Queensland! Or failing that Victoria!”, but it also seems that that might not be the case.

Lachlan: Yeah, so it's still within the same general family group, the Chigutisaurs as Siderops and also Koolasuchus who are hypothesised to be quite closely related. But it is more closely related to a couple of taxa from South America and India. So there's a temnospondyl called Kuttycephalus from India and one called Compsocerops which is from Brazil. And they're the two closest relatives to Arenaerpeton.

Now when I first saw that and saw that it wasn't that closely related to Siderops, I was also very confused. I'm like, “Oh, hang on, what's going on here?” But then when you think about it in the whole big picture, this thing was living in the Triassic period as part of Gondwana and so were these other two that I just mentioned, the ones from Brazil and from India. And so, it's closely related to the animals from the same family that were living at the same time! There was some sort of divergence that happens in the group that eventually sprung Siderops and Koolasuchus, I guess.

Adele: Yep. So Siderops and Koolasuchus are still closely related to one another, according to your analysis? Or did like Arenaerpeton kind of shake things up a little bit in terms of other related taxa?

Lachlan: It didn't shake things up too much. The problem with Koolasuchus is that we can't really put it into any kind of phylogenetic analysis because there isn't that much known of it. So the holotype of Koolasuchus is more or less just a mandible. There's been no described cranial material of Koolasuchus at all. There's a few little post-cranial bits and pieces that were described at the same time as the mandible, but they're not very taxonomically informative. And so that's a bit of a problem with Koolasuchus is that you can't really put it reliably into any phylogenetic analysis without the entire analysis having a heart attack. But Siderops we can. As I mentioned, Siderops is like a near-complete skeleton. And so that's included in a lot of analyses of temnospondyls. When I put Arenaerpeton into it, yeah, it didn't shake things up too much. We still have what we hypothesised originally as the most basal or most ancient member of that family group, which is also from Australia. It's one of the Triassic ones from Queensland, an animal called Keratobrachyops. And then apart from that, it hasn't actually stuffed things up too much.

Adele: Well, that's nice. Nice change of pace for an Australian fossil to not cause the phylogenetic analysis to have a heart attack. I know that, that has sometimes been the case with ornithopod dinosaurs come to mind. Because it's quite basal and quite early branching, but yeah, nice to hear.

Lachlan: Yeah, even like Muttaburrasaurus is still a bit of a weirdo, isn't it? Amongst all like, ornithopods which is kind of strange. Yeah. Because like, yeah, we have great material of it.

Adele: Yeah, I believe there's, off the top of my head, there's the holotype, there's referred specimens as well. We were talking before we hit record, just about every museum in Australia has a cast of Muttaburrasaurus. Like I technically live closer to Muttaburra than I do to Winton. Don't tell anyone I said that, it's a very well-guarded secret. But when I went down to Tasmania with my mum and there was a Muttaburrasaurus on display, I was like, what are you doing here? I've travelled hundreds, thousands of kilometres… to see my neighbour! What's going on?

Lachlan: Yeah, and it is a bit of a weirdo because they still can't place it properly phylogenetically, I think. And that's odd to me because, like we mentioned, it's got really great material. Sometimes the other issue with a lot of these Australian prehistoric animals that we put into these analyses is that the material is really isolated and not very diagnostic. There are a number of Australian dinosaurs and other Australian fossil animals known from single bones and they're given a taxonomic name. It's hard to put something like that...

Adele: Work out what's what.

Lachlan: Yeah, especially when it's like just the proximal end of a femur or something like that and that's given a scientific name like how can you code half a bone into a phylogenetic matrix that has 120 characters of the entire skeleton?

Adele: Or how do you make sure that, that femur isn't the same species as a hand bone? You don't at the end of the day. Another kind of issue as well, I guess, is if Australia is part of the big southern supercontinent Gondwana and our neighbours are South America, Africa, Antarctica and New Zealand, if we don't know a lot of the fossil record from eastern Gondwana… you know, New Zealand and Antarctica, well it's hard to make sense of the family tree when you have so much missing.

Lachlan: Yeah, and I think it's only been recently, comparatively speaking, that the connections that Australia has with Mesozoic faunas from other parts of Gondwana, especially the dinosaur faunas, are very similar between Australia and South America. Is that the same with pterosaurs?

Adele: Yeah. Pterosaurs are also weird, though, because they can fly. I'm guessing temnospondyls can't fly.

Lachlan: No, there's one weird thing that they can't do. Haha. I could have just dropped a bomb shell there and said, yeah, they could also fly. But no, they could swim, they could walk on land, they ate their babies. They did not fly.

Adele: Once this new temnospondyl is out, are you then completely done with the group or are there maybe some more temnospondyl things for you to work on? You don't have to give anything specific away, but should we keep an eye out for more papers?

Lachlan: Yes, do keep an eye out. I'm going to be consistently working on this group. Now, hopefully for a long time. I've spent four years of my life getting to know them quite intimately. And so I'm not going to change groups again and go and work on dinosaurs all of a sudden. So yes, there are some more very exciting discoveries in Australian temnospondyl paleontology that will be forthcoming in the next little while. And if this one didn't excite you, then the next ones probably will.

Adele: I'm so excited for everyone to hear about this incredible discovery and all of the science that you've done on it. I think the media is going to absolutely eat it up. There just seems to be such a big appetite for paleontological discoveries across all the different groups that you can think of.

Lachlan: Yeah, we can chalk that up to a few reasons. Obviously, the people that came just before we started. So, for example, I worked on Lightning Ridge material for my master's, Lightning Ridge crocodile material. But the stuff that's come out of Lightning Ridge recently is all up to that team of people led by Phil Bell at UNE. We've got two new dinosaur species that have been named out of that stuff, and new crocodile species.

So there's been a lot happening that's been generating a lot of public interest in paleontology in Australia again and we're not seen as this barren wasteland where it's all flat and we just have trilobites. We have some cool vertebrate material too from the Mesozoic! So I count myself really lucky that I get to work on this stuff now. I haven't had to go out and dig up any of it. The material that I've worked on for my PhD’s all been in museum collections. Yeah, I just count myself really lucky that people come to me and see me as somebody who would hopefully do these amazing fossils justice in describing them and giving them a place in Australian paleontology.

Adele: It's very humbling to be approached by someone with an incredible fossil and be entrusted with the responsibility of describing it scientifically.

Lachlan: And both you and I have been really lucky that we've had that happen several times. You had it with Ferrodraco as well. It's just one of those things where… You don't dream of these things happening, especially when you're a kid and you're growing up and you want to be a palaeontologist, you don't think someone's going to come with you with this amazing fossil. Say, “Hey, look, this is an amazing fossil and now you can name it!”

Adele: It's a fairy godmother moment, essentially, to be plucked out of obscurity and say, “You're the one! Here, throw the ring into the volcano!”

Lachlan: Yeah, or, “Hey, there's this amazing fossil that's been in the museum collection for over 20 years that no one's described yet. Do you want to do a PhD on it?”

Adele: There's definitely a component of being in the right place at the right time, but you also took the initiative to search around and ask about what potential projects that you could work on.

Lachlan: Absolutely, and we've all got to be motivated to get where we're at, right?

Adele: 100%. We're not doing it because there's lots of money to be made, it's because we love doing it. And honestly, I can't imagine doing anything else with my life.

Lachlan: Yeah, absolutely. And like I said, it was a love that I had from when I was a kid. And yeah, hopefully discoveries like this can keep inspiring the next generation.

Adele: Yeah. If anyone is building a retaining wall and sees something strange, contact your local museum. And if it turns out to be a weird, fanged, tusked, possibly toxic amphibian. You know who to call. But yeah, is there anything you wanted to plug other than come see this amazing fossil when it is finally put on public display?

Lachlan: Yep. Keep an eye on the media that comes from the Australian Museum about when the fossil might come on display. Have a look at the paper when it is released and by the time this podcast is released, the paper should also be out. So it's going to be in the Journal of Vertebrate Paleontology. And yeah, I hope that lots of people come and see the fossil and are excited by it like I am.

Adele: Lachlan, thank you so much for being on the show and telling us all about Arenaerpeton supinatus, as well as Temnospondyls in general. I've learned so much about Arenaerpeton supinatus, as well as Temnospondyls in general. I've learned so much about these ancient amphibians and I cannot wait to see what new research you have on this amazing group of animals.

If you want to be in the loop and find out when Arenaerpeton supinatus finally goes on display, follow the Australian Museum, I'm sure they'll make the announcement in their newsletter and on social media so keep an eye out for that.

Hope you enjoyed hearing about temnospondyls... again. If I'd known they'd pop up again and again I would've asked Jenny Zhao who did the podcast cover art to chuck one in there but who knows. Maybe I'll get her to revamp the cover art for the show and it'll feature the greatest hits and fossils from the episodes with the most downloads.

By the way if you love the podcast cover art, there's a sticker of it, as well as a giant sticker sheet with the different dig tools, animals and fossils featured. You can find those in our online shop, just go to palsinpalaeo.com or check out the link in the shownotes.

If you want to support the show but money's tight or you're not into stickers, that's cool too! If you enjoyed the show and want to help spread the word, leaving a review and rating helps immensely. It takes, not even a minute and it helps the show rank higher when folks search for shows like this one.

The podcast wouldn't be what it is today with help from Francy, who edits the show and sings the theme song. He's super talented, you can find him on Instagram @hellofrancy and keep up to date with his various projects, otherwise his band called Hello Kelly are worth a follow. In terms of the new bands I've gotten into over the last 5 or so years, they're one of my favourites. If you haven't already go check out their album Sweet Nostalgia, it's heartbreakingly good. There's guitars, there's synths, it has everything you could ever want from a indie pop rock album and more.

Shout out to my buddy César Puechmarin, he helped me figure out what I was doing with the podcast when I first started and also edited our early episodes. He's phenomenonal, super knowledgeable when it comes to frogs and birds and his podcast Death By Birding is chaos but there's heaps of good info too so, if you've binged the entire back catalogue of Pals in Palaeo, definitely check out Death By Birding.

The podcast cover art came together through the magic of Crumpet Club House a collective of freelance creatives cofounded by Jenny Zhao who I mentioned before and Amy Franks, working with them was easy and effortless and I'm still in love with the podcast cover art.

Final thank you, is yours. I couldn't do the show if no one was listening, it's been super fun connecting with people who love palaeontology as much as I do and getting to share what I'm passionate about with folks who know about dinosaurs but aren't familiar with the stuff we find in Australia. Fossils are weird relics from past worlds and getting to share facts on them is one of my favourite things to do, so again thank you so much for listening.

It's been the best of times, it's been the blurst of times

Pals in Palaeo will be back soon to talk about new discoveries on old fossils but until then, just keep digging, look after yourself and I'll speak to you soon.
 
 
 REFERENCES
 
Random Fossil Fact
Cannibalism in a small growth stage of the Early Permian branchiosaurid Apateon gracilis (Credner, 1881) from Saxony

Arenaerpeton supinatus
A new chigutisaurid (Brachyopoidea, Temnospondyli) with soft tissue preservation from the Triassic Sydney Basin, New South Wales, Australia

Temnospondyl tooth from Talbragar
The first tetrapod remains from the Upper Jurassic Talbragar Fossil Fish Bed

Estimating temno body size
On the estimation of body mass in temnospondyls: a case study using the large-bodied Eryops and Paracyclotosaurus

McGrath’s Flat
The discovery of an exceptional new fossil site offers a glimpse into Australia’s ancient rainforests

Siderops
Siderops kehli - Giant Jurassic amphibian
 

Isisfordia molnari – Cretaceous croc
Isisfordia molnari sp. nov., a new basal eusuchian from the mid-Cretaceous of Lightning Ridge, Australia