11. Fossil Skinks

Join Adele and Dr Kailah Thorn, the Australian lizard queen on an odyssey through the fossil skink record! We discuss the indestructible shingleback lizards, fieldwork at Lake Frome, lizards bulldozing through fields of flowers and the biggest skink from Australia, Tiliqua frangens aka the mega chonk. Plus facts on Proegernia mikebulli, the the oldest skink ever found in Australia and an ancestor to the modern bluetongue from the Oligocene (25 million years old), as well as Egernia gillespieae named after fossil preparator Dr Anna Gillespie

Adele Pentland

11/8/202372 min read

Adele: Today on the show we are chatting with Dr Kailah Thorn an expert on fossil skinks and the Australian lizard queen. This episode we talk about the indestructible nature of modern shinglebacks, fossils from Lake Frome, lizards bulldozing fields of flowers, and Tiliqua frangens aka the Mega Chonk.

Pals in Palaeo presents Fossil Skinks with Kailah Thorn

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Pals in Palaeo recognises First Nations People as the original biologists and ecologists of this land and their oral histories which record Australia's megafauna. In particular we recognise the Buandig, Bindjali, Ngarrindjeri, Boodjamulla people and the connections First Nations people have with the land, sky, waterways and their 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 Whadjuk Nyoongar country, as well as Koa country, and the fossils skinks discussed in this episode were found in sites across Australia.

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This is Pals in Palaeo your backstage pass into the world of palaeontology.

I'm your host, the Ms Frizzle of Aussie Palaeo Adele Pentland. You can keep up to date with the show by following Pals in Palaeo on Instagram.

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Today's episode is chock full of info on fossil skinks and I am bursting to introduce you to Kailah BUT first I am bound by state law to tell you a Random Fossil Fact. It's written in the constitution of the show, article 51 section B written in fine print.

Today's Random Fossil Fact comes from the Curator Mammalogy at the Western Australian Museum, Dr Kenny Travoullion. So this episode is broken up into 2 interviews, one recorded at Palaeo Down Under 3 which was in Perth and we recorded the 2nd part virtually. Now, it just so happens that when we recorded Part 2, Kenny had a new paper come out on biofluoresent mammal fur.

Ok so this a little bit convoluted but just stick with me because there's going to be a massive pay off at the end. Ok so, first things first: a group of researchers discovered that the Platypus, which is a weird type of mammal endemic to Australia had biofluoresent fur. And everyone thought, OK, well male Platypus they have a toxic spur and when western scientists first saw taxidermy specimens of the platypus they thought it was a joke because they look so strange. So everyone was like "yeah, okay that kind of checks out. It's pretty onbrand for the platypus.

Kenny though, being the brilliant scientist that he is, decided to test out whether other specimens, other mammals, had biofluoresent fur so he took a UV torch through the collections at Boola Bardip the Western Australian Museum and he made a staggering discovery.

We got a hint that a big paper was in the works, but you might have missed it. So in 2022 there was an article written by Zoe Kean and Lucie Cutting from the ABC and they were inspired by the platypus study and wanted to figure out whether the Thylacine also glowed.

Now the Thylacine, also known as the Tasmanian tiger, went extinct in 1936 after it was wiped out in Tasmania by Europeans, by colonisers, but, as it turns out Thylacines also have biofluoresent fur.

And they're not the only ones. Dr Kenny Travoullion and colleagues published a new paper in Royal Society Open Science, titled All-a-glow: spectral characteristics confirm widespread fluorescence for mammals.

That paper came out the day Kailah and I recorded Part 2 of this podcast interview and since Kailah and Kenny work together at Boola Bardip, at Western Australian Museum, it was a no brainer to share this fact as the fact for today's episode.

Kenny and colleagues found that 125 species of mammal, from 27 orders and 79 families have biofluoresent fur. It's a trait more common in nocturnal animals, which kind of makes sense, as well as things that live in trees, on the ground and burrow.

I love this paper because not only does it incorporate extinct and living animals which is a big theme for today's show, but it also challenges pre-existing ideas and you know we're all about that here on Pals in Palaeo. I'll post a bunch of links in the shownotes so you can read more, including the paper by Travoullion et al. which is in open access so anyone can check that one out.

We've talked fluorescence in fur, let's now shift gears and talk scales and skinks with Dr Kailah Thorn.

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Adele: This is Pals and palaeo, the show where we talk about the form, function, and family groupings of some incredible fossils. Today on the show, I have a really special guest, Dr. Kailah Thorn.

Kailah: Thanks for having me.

A: No worries. We are currently recording, it's the first day of Palaeo Down Under 3. So it's really exciting time to finally be back in person and seeing some amazing talks on palaeontology.

K: And this is your first time at Boola Bardip as well?

A: Yes.

K: Yeah. WA Museum. Pretty snazzy. So we pinched one of the rooms to record in. Yep.

A: It kind of helps that Kailah works here as well. So what is your current position with the museum?

K: Yeah, so my current position is akin to like collection manager at other museums, but at the WA Museum our title is technical officer and I work in terrestrial vertebrates. So I look after the birds, mammals, reptiles, and amphibians, which is pretty diverse and pretty exciting. So I get to work with living animals. I get to make them not living animals and then process them to make skeletons and skins, which then become references for palaeontology, which is something that I used a lot for my PhD. And it's really nice to see how it's done and to be able to contribute to that kind of stuff.

A: Yep. So mostly bones, not sort of the taxidermy side of things?

K: Oh no, the whole lot.

A: Oh, the whole lot. Okay, wow!

K: So I got to learn how to pickle frogs and lizards, which is kind of cool, and how to take tissue samples. And I'm now responsible for tens of thousands, if not hundreds of thousands of frozen tissues in negative 80 degree freezers for genetic work. I also get to process study skins. So I don't do full mount taxidermy.

The museum has a taxidermist for that, but we make study skins where we'll… yeah, basically skin the animal and then we dry the skin out using borax and then stuff them so they're roughly their right shape but they're kind of just like a sausage. We pin them to a board and they dry in that fixed shape and then they go into the collection afterwards.

So they're pretty easy to look after and pretty easy to do as a process. Time consuming but simple. And we also prepare skeletons. So the mammal skeleton collection is, it's a pretty standard collection type. There's lots of skeletal mammals, which is really handy if you're a palaeomammologist.


K: There's lots of skulls and teeth and post-cranial bones in collections across Australia. Some bird skeletons already exist at WAM, but the collection could definitely use expanding. Most people use study skins for birds as well. And reptiles in Australia, one of the reasons why it's so hard to study fossil squamates is that we don't really create reptile or frog skeletal collections.

And I can testify that it's an uphill battle to convince any neo-herpetologist or just a herpetologist who works on living stuff to not immediately pickle everything. So that's been one of the fun parts of my job is slowly convincing my boss, Paul Dowdy, that every lizard we catch doesn't immediately need to go into formalin and ethanol. If we have extras or something unusual, we can also freeze them and then turn them into skeletons later.

A: Yeah, that's sort of wild for me to think about all these different facets. Even though I'm a palaeontologist, I work on a group that is now completely extinct. So even just, you know, the tissue samples and all these things and relating it back to modern day groups is just something that completely sort of goes over my head. And you sort of in this role, having come from a background of working on fossil skinks is what you did your PhD on?

K: Yeah. So I was…

A: at Flinders?

K: Yeah.

A: Oh, I got it right. Look at me go. I get the universities and South Australia mixed up all the time. It's a real problem.

K: Hey, well, I mean, they're merging two of them, so it's about to get more simple.

A: Yep. I said that to my husband the other day. I'm like, “Oh! I have less stuff to remember!”

K: So yeah, I did my PhD at Flinders, but I kind of started in WA. I did honors with the WA Museum and then went to do PhD at Flinders and then now came back to WA for jobs. But yeah, so I worked on fossil tiliquans, which are blue-tongued lizards and their relatives. So they' social skinks. So like all the spiny-tailed skinks, blue-tongued, bobtails, shinglebacks, whatever you want to call them. Every state has a different name, sleepy lizards and they're ilk.

And they have a couple of, they have this really unusual family member called Corucia zebrata, which is based in the Solomon Islands, called the monkey-tailed skink. And they have really tall, wide head shape, a semi-prehensile tail, and live arboreally and eat foliage, which is so odd, right? For a lizard.

A: Classic island animal, just.

K: Let's just throw out the rule book for skinks, hey?

A: Let me eat plants.


K: I'm just going to be monkey-like. And they're quite common in the pet trade and locally, I think they're also eaten. But it means it's hard to do field work on those groups and to monitor conservation-wise how Coruciais doing, but it's a pretty cool animal.

And it also kind of helps us connect where living skinks possibly came from and how morphologically diverse they can be from Australia. So, yeah. So throughout my PhD, I had the opportunity to work on a bunch of different fossils. It was a combination of different places in Australia and different time periods. I think I managed to sample it quite evenly.

A: So how extensive is the fossil skink record? Like how many millions of years have they been around?

K: In Australia, it's a bit of a mix. So in terms of how well spread out they are and like how the oldest records are, we've got the oldest fossil skink found in Australia so far is Proegernia mikebulli, which was one of the chapters of my PhD thesis.

I just published open access. Proegernia was pretty fragmentary. It's from the Namba formation, which is a Lake Frome basin in sort of central South Australia. Basically we did field work out on the side of salt lakes. The weather was rough-

A: It sounds very- oh, I was gonna say it sounds picturesque.

K: Oh, it is.

A: Maybe not.

K: It is. And you know, if you go there and it's overcast and relatively cool, it's a really nice place to do field work. There's no pesky vegetation in the way. You can pretty much get everywhere in four wheel drives. You don't have to do big walks. And when you do it's flat. So that's great.

But when it's hot and when it's sunny, there is no shade. The tallest trees are sort of these scrappy, sort of, she-oak-y things. We were stringing up tarps one year because it was like 45 degrees in the shade and trying to do full work in the dark in the morning so that you can knock off by about 10 a.m. And it doesn't really work that well, but, you know, none of us died. We made it through and we have pretty good fossils to show for it.

But yeah, so that site's fairly old. It's sort of like 27 and a half million years.

A: Oh wow, OK.

K: And it's a pretty diverse sort of… Lake Edge deposit where we've got a combination of aquatic animals. So there's crocodiles, lungfish, turtles, and other kinds of fish as well, as well as Obdurodon, so the early platypus, which is pretty cool, and dolphins, which is really neat. So Eric Fitzgerald has published a paper on some of the dolphin bits that have been found out there.

A: That's a wild card since we don't have… dolphins here in Australia.

K: In central Australia.

A: Freshwater, I'm guessing.

K: Yeah, so that's pretty neat. And then, you know, in and amongst all of this freshwater deposit, you've also got some of the animals that have been living around this water source. So we hypothesize that they've kind of been washed in to these sort of concentrated lenses, or they've died on the side of the lake during a period of drought or something like that, and then been buried by flash flooding, silt or something.

A: Yeah, sort of using the rocks as well to piece together part of the story of this animal. Is it showing sort of signs of being moved, like in terms of the way the bones are laid out?

K: Kind of disarticulated in a complete mess and they're jumbled up among. So we called it the fish lens when we're in the field because it's this sort of lens in our lakeside deposit that's almost entirely fish bone, which looks very different to terrestrial vertebrate bones, where fish bone kind of looks… sort of waxy and partly translucent in this deposit. Most of them are sort of spines and vertebrae. And they're just, yeah.

A: And spines would be like bones from the fins themselves?

K: Yeah, it's like the rays and things like that.

A: Yep.

K: And then, yeah, in the fish lens, we're finding all these aquatic fragments, bits of turtle shell, but then also some of the really small terrestrial vertebrates. So there's tiny little early sort of Dasyurid type things.

A: Sorry, what's that?

K: Oh, so like tiny little marsupial mice are kind of shaped animals with little pointy teeth.

A: Oh OK.

K: There's small possums, but these are all representatives of big marsupial radiations today, but they're so early that it's kind of, they are all sort of melding into one at this point. So, you know, possums and kangaroos are all looking kind of similar, well, at least to my eye, because I don't work on fossil mammals anymore. And they've got early thylacinids from out that way as well. A lot of the sort of early animals that eventually ended up becoming, you know, wombats and diprotodons and things like that, are like members of those groups. They're sort of like sheep sized at this point in time. All the mammals are significantly smaller. And it's also really cool. They found koalas on the side of the lake as well. So koalas are a pretty ancient group. So it's a super diverse deposit and there's like crocodiles and…


K: Yeah, it's a really cool palaeo environment and yeah, more and more stuff still coming out about it, even though people have been looking at it since the sort of 70s. Well, earlier than that, but a lot of bulk of the work was done around the 70s and Tom Rich took the army out there to do some digs at one point. So…

A: It sounds like something Tom Rich would do. I feel like he's been across a lot of Australia. I know there's stuff that he's collected from Queensland, like way back in the day. And of course, Dinosaur Dreaming as well.

K: Yeah.

A: Good on ya Tom.

K: He's just sort of like, “there could be something cool here. I'm just gonna throw all my energy at it and hope for the best” and lucked out. Yeah.

A: Oh, that's awesome. It's so funny that you mentioned mammals because when I see skinks and fossil skinks, I think of you now.

K: Yeah, we don't talk about the mammals times, the dark times. No, yeah, so my gateway to palaeontology was when I was at UWA where I was doing zoology in undergrad. I did three weeks of osteology in second year, Zool subjects. They don't teach that anymore, but it was like not that much anyway. And I thoroughly enjoy working with bones. And I said, how do I get to do more of this?

A: Oh, so you weren't one of those kids who's like, I'm gonna be a palaeontologist.

K: I mean, I was one of those kids, but then it was kind of like-

A: I should get a real job?

K: Yeah. And everyone's just sort of like, well, that's not gonna be a real job. You know, my parents have pretty practical real jobs, you know, like I grew up in a country pub because they own and run a family business. And then my mom ended up doing nursing. And so it's very, very practical jobs, not really like blue sky stuff.

So I thought, yeah, well, you know, “maybe this is a thing” and I enjoy it. And I was, I did quite well in the pracs and that subject. And the lecturer Jamie O'Shea was like, ah, well, if you like working with bones, I supervised a PhD project of this woman called Natalie Warburton. And the other supervisor was Gavin Prideaux. You should go and email Gavin Prideaux, he has this email address, can ask him about how to get into doing bones and palaeontology.

And a previous student who had gone through the exact same degree as me, the same combination of majors, which was Aidan Couzens. And so I emailed both of them and Aidan was like, pick up geology, it's a really good combo. And then Gavin was like, you should come over and do the Flinders Vertebrate Palaeontology subject, which at the time was like a summer intensive school. So it was two weeks down in Naracoorte. And it was run by Liz Reed at the time when she was at Flinders.


K: And I had a blast. It was...

A: It sounds so fun. It's like palaeo summer camp.

K: Yeah. And, you know, and like some of the people that were in that topic that didn't end up doing palaeontology for whatever reason, I still know and sort of see them around doing other cool sciencey things. So I think the person who gave me a lift from Naracoorte back to Adelaide so I could fly home, was like Erinn Fagan-Jeffries, who now works on wasps and taxonomy.

So Laura, who was on that field trip, is now doing engagement stuff with the South Australian Museum when she can as well. So you meet a lot of interesting people in summer schools. And then I came back and wanted to keep doing palaeo. And I made a connection with someone at the university from geology, Jenny Bevan. And she said, “Oh, well I know some palaeontologists in WA. My husband works at the WA Museum and he's head of Earth and Planetary Sciences.”

There's two palaeontologists at the museum. Michael Siverson, who works on sort of Cretaceous sharks.

A: He's the like the fossil shark guy in Australia.

K: And Alex Baines, who wasn't a staff member, but he's basically been at the WA Museum since he did his PhD there.

A: Oh, so part of the furniture.

K: Yeah, basically. And Alex works on Quaternary rodents.

A: So that's recent.

K: Yeah. He focuses on rodents, they're his thing, but he likes palaeoecology. So changes in community composition through time as tracked by like presence, absence, and abundance of small mammals in cave deposits. That's Alex's bread and butter. And I really liked that topic because that's kind of what Flinders was doing down in Naracoorte. I really liked sorting through tiny little bones or micro vertebrates.

A: I find it super relaxing.

K: Yeah. Just doing any sorting.

A: Yeah. You can just kind of chuck on a podcast, like get lost in it. Yeah. And it's not like prepping because I know sometimes it's like, okay, if I do this wrong, I will destroy this.

K: Yeah.

A: But it's just like, oh, it's just in the wrong pile.

K: Yeah.

A: You know, it's very low pressure.

K: Yeah. Prepping is high pressure and you can get very frustrating when you stuff something up or something's not working or if it's a really difficult fossil. Whereas sorting is just so forgiving. There'll be a giant pile and you slowly chip away at it.


K: Yeah. And then you get to sort everything into nice, neat little sorted piles and vials and then label them. And that makes me happy. It's like, how did you get into collection management? OCD.

A: I like order.

K: Yes, things must be labeled. So, yeah, so that's basically what I ended up doing my honours on was specifically palaeoecology of small mammals, because Alex Baines was my supervisor. So it became very intimate with various cusps on rodent molars.

A: And they're super diagnostic. It sounds weird. Like every group has their weird little idiosyncrasies of this one area here, this is where all the IDs for all species is.

K: Where the magic happens. Mammalogists are still obsessed with teeth. It's like.

A: I mean, it helps that they find them quite often because they fossilize quite well being a hard thing that they used to eat.

K: They’re kind of spoiled actually. Yeah. Which is probably why, if you're looking at Cenozoic deposits in Australia, mammals have been the most heavily studied group. Birds and reptiles not so much and until sort of semi recently. And so it's kind of really exciting to have moved away from mammals, even though like, you know, I don't dislike them, you know, but there's a lot of people working in that space and herpetology, like reptiles was always my love. That's why I did zoology originally. And to be able to get into reptile palaeontology was, was pretty exciting.

A: So transitioning from mammals for honors into herps, reptiles. Fossil skinks for your PhD. Were you still doing palaeoecology or were you sort of sort of niching down and focusing on, you know, one particular specimen at a time?

K: Yeah, good question. Sometimes I ponder that myself. So I went from this palaeoecology background and wanting to work on reptiles and I found a paper by a woman called Marcy Hollinshead who was supervised by like Jim Mead and Chris Bell to work on fossil skinks from the Devil's Lair deposit. So Devil's Lair-

A: That's a great name.

K: Yeah, so it's actually, it's an archeological deposit, so we can't really work on it anymore, but she wanted to see if she could identify the fossil skinks and if there was any sort of palaeoecological trend in that deposit. And she used that sort of genus level identifications for the tiliquans, so the blue tongue lizards and their relatives, and then tracked that through the layers of the pit, which was really cool. And I read that paper and was like, this is really neat. I like how simple sort of-


A: It's very pragmatic.

K: Yeah, so the characters that she figured out in this paper, which is a chapter of her PhD, were from looking at a bunch of reference specimens, she was able to say, well, this genus has this combination of characters that it's unique, and then it could basically eliminate other ones. And got a basic trend out of it. And I wanted to do that.

A: Palaeontology is often just a process of elimination.

K: Yeah.

A: Sometimes it's more just ruling things out to be like, what am I looking at?

K: Yeah, pretty much. And I really liked that paper. And I basically asked… At that time, this was before I started my PhD, but I'd moved to Flinders and had been working there for a couple of years at that point, just as a technician for Gavin. And I asked the question like, “Hey, I really liked this paper and I'm enjoying sorting the reptiles from the Nullarbor caves. Any chance I could do this for a PhD?”

And Gavin's like, that's a superb question. No one's asked that before. I'll put you in contact with Mark Hutchinson and Mark was like a giddy school kid apparently. He was super excited about it. He'd already written this project proposal like 10 years prior and was waiting for someone to ask.

A: Really? Oh, that's so funny. Convergent on the same idea.

K: Yeah, he was like, I really want someone to work on this group of fossil reptile.

A: It's so great, but he wrote it down, but you didn't know about it either. No. It was just something that you were genuinely passionate about.

K: Yeah. So kind of just, and I'd been helping out with the pracs that Mark Hutcherson had run for a couple of years. So I'd met him before.

A: That always helps.

K: And we'd sort of, you know, we work well together in the pracs and I ask good questions and actually made him miss a ride home once because we got stuck talking about a python vertebrae for about half an hour.

A: So that's always good as well because another thing with PhDs that some people don't consider is that you're going to be with that supervisor for at least three years. You want to have a really good working relationship with them.

K: You need to vibe!

A: You need to communicate clearly.

K: Yeah. And yeah, I definitely hit it off with Hutcho nerding out about ripped. He's a walking encyclopedia. I could ask him any question and he has the answers and...


K: We both got excited about weird little niche things about reptile osteology, which was, it was really good. And even now, like he messaged me today about something and I was like, “Oh, I can't give you an answer because I'm at a conference.” And he was like, “Oh, which conference?”

And I sent him a photo of the sort of lineup of speakers that I'm surrounded by tomorrow afternoon with other palaeoherpetology talks and Mark's like, “Oh, give them all big wet sloppy kisses from me.” Cause he knows them all. So it was really nice.

A: Yeah. The really nice thing about Palaeo Down Under 3 as well is that like the aussie palaeo community is pretty small. So even if you don't know people to begin with, it's not long before you…

K: Yeah. And even like, I think cause I was helping distribute all the goodie bags and name tags, there were so many people who I know their names and their faces.

A: Or you follow them on Twitter or Instagram, whatever it is.

K: Yeah. And so you just, or you know them through other people.

A: Exactly.

K: So like, I don't work on invertebrates, but I know who Pato is. And you know, we have friends in common because he's done full work with Aaron Camens. And so like, Pato walks in and I was like, oh, I saw your bag and I had to hand to him sort of he got to cut the queue, but it's like, and he's like, “Oh, Kailah.” And I'm like, “I don't think we've ever actually had like a long conversation,” but we know-

A: It's funny, and there's other moments as well, like, oh, we actually haven't met in person, but I've chatted to you heaps. Yeah.

K: Yeah, that's also really nice. It's been really nice to sort of meet people through emails, through either collection inquiries or research questions or just, yeah,

A: It's been nice to thank people in person, being like, “Oh, you helped me out with this random thing. Thank you so much.”

K: I think we're a pretty accepting bunch.

A: I think we all know how weird we are.

K: Yeah. And we just go with it.

K: We lean in to the niche. But yeah, so I, for my PhD, we had to try and figure out how we're gonna identify these reptiles and sort of build on, originally what Marcy did, and then take that and apply it more broadly across Australian deposits.

And to do that, we needed to figure out how to identify fossil lizards. And so I never actually got to do any palaeoecology during my PhD as sort of chapters for my thesis. It was always-

A: You were too busy doing other stuff.

K: Just doing core concept based methods to enable palaeoecology later. So how do I identify fossil skinks? And then applying it to different material through time. So I worked on describing a skink from Riversleigh. So we've got-

A: Is that the recent one?


K: That's the first one I put out. So that's 15 million years old. So that came out in 2019. So that's a Egernia gillespieae. We named it after Anna Gillespie, who's one of the preparators at UNSW.

A: Oh, that's gorgeous.

K: Yeah. Well, I mean, no one puts so much love, time and effort into preparing a tiny little skink like Anna did. It was amazing.

A: It's really nice as well when you know, you've just got like a good prepper who's got your back and it's like, I can leave it with them.

K: Well, I just saw the end result. So she had… this is material that someone had sent to Mark Hutchinson in the early 90s when I was a toddler.

And he just hadn't got around to finishing those publications. So he presented on this material at CAVEPS in 2013, which I saw and was excited about at the time. And then for whatever reason, didn't pursue it immediately.

And then… he basically had started working on it and then was like, “Oh, here you go. Here's something that's ready to roll.” And it was a really nice opportunity to work on material that was associated because reptile skulls, as you will know, fall apart into all these different little pieces.

A: Yeah. It's not like a human skull where it's just like lower jaw, the rest, one, like two units, essentially.

K: Mammals only fall apart if they're babies. So reptiles just continuously do it. And it's, you know, the bain of our entire field.

A: And I know with pterosaurs, it's like 30 bones-ish, or dinosaurs as well. It's like 30 bones for basically the two sides and stuff. And they kind of fuse together, but then they just kind of fall apart.

K: And there's no connective tissue. They just go every which way. And so, Riversleigh has exceptional preservation, which is why it's a World Heritage Area,

A: with Naracoorte.

K: Yeah, yeah. But the cool thing about Riversleigh is because it's sort of cemented in this limestone. So things come out the way they went in.

A: Oh, that's nice. So that was very considerate of the fossils to do that for us. I love it when they do that.


K: And so this lizard skull came out partially articulated and very much associated.

A: So in life position.

K: Yeah.

A: And then it had other bits with it.

K: Other bits with it. And so, and Anna had managed to keep it like that. So she's using acid, like, you know, an acid digestion. And then you sort of harden the bones as you start to see them. So the acid doesn't digest the bone only the limestone surrounding it. And she saw these lizard bits coming out and did an amazing job keeping them together.

And keeping them associated with one another so that when it came time to actually work on the material, we've got-

A: All that information is there, the context as well.

K: Yeah, from the skull and then some limb bones as well. And it was just, yeah, it was really cool to be able to work on that. And it ended up being a really nice sort of intro into palaeoherpetology for me, nice soft one, I suppose.

And then, yeah, Proegernia was definitely a lot more difficult. So yeah, Proegernia was the really nice super hot salt lake site, but all of those fossils were basically sorted from amongst fish bones. So they're tiny fragments of jaws. Everything's disarticulated.

We definitely don't have anything from associated individuals. So it was a case of, finding all the reptile bits, trying to figure out if we had more than one species or more than one morphotype, and they're all fragmentary and they're all very, very tiny. And that was a real challenge to wrap my head around.

A: For anyone who's not based in Australia and isn't familiar with what a skink, it's a lizard. Some of the big ones would be what? Like sort of hand size?

K: Yeah, so most skinks are around sort of two grams or less in body weight. It's shorter than seven centimeters, not including their tail. So the little lizards that you find calling on your brick walls and they've got shiny overlapping scales and they don't normally have a very noticeable neck. They're kind of-

A: Rugby player lizards.

K: Yeah, most of them aren't that chunky.

A: No, I meant the neck wise, but I do take your point.

K: But yeah, so the- kind of the lizards that everyone takes for granted. They have a fairly global distribution except for Antarctica, obviously. So in North America, they have like little blue-tailed skinks.

A: And they can drop their tail?

K: Yes, skinks can. They have a caudal autonomy, so they can drop their tails when they feel threatened.

A: Then the tail flails around as a distraction for the predator so that hopefully the predator doesn't eat the actual skink.

K: Yeah, geckos can do that too, but geckos sort of have like loose skin and they're sort of chunky looking, and they have...dull patina on their scales.


A: Yeah. I think of geckos as being like quite squishy.

K: Yeah, they look squishy.

A: Whereas a skink to me is kind of metallic.

K: Yeah, so they're shiny, they have reflective overlapping scales. And so a defining feature of skinks is that they have osteoderms, they have bony plates in their skin. So when we CT scan them, for example, they kind of look the same as on the outside because they're just covered in bone.

But yeah, most of them it's only very, very small and they're like little sort of ossicles inside each scale. So they're not like one big solid scale for each scale. But it forms as like an armor plating for them.

A: And osteoderms as well are something that's present in multiple groups of reptiles, in dinosaurs, in crocs, and-

K: A whole suite of different animals. So yeah, and osteoderms make it really easy. If you happen to get some sort of exceptionally preserved lizard, you can see the osteoderms and it'll give you an external shape of an animal, but we don't really have anything like that in Australia.

So it was a bit challenging to work on this group, but elsewhere in the world, they've found some pretty cool, like associated skeletons with all their osteoderms preserving external shape and stuff like that, which is nice.

Some of them can be taxonomically informative.

A: The osteoderms?

K: Yeah, so spoiler alert for my talk tomorrow, there's a spiny-tailed skink osteoderm in one of the Nullarbor cave deposits. There's no spiny-tailed skinks in that area of the Nullarbor anymore. And so these are coming from the Pleistocene unit. So it would have been a very different environment.

A: Pleistocene is how many million years old?

K: So Pleistocene is sort of like, I don't know, two and a half million to like 12,000 years ago.

A: Okay.

K: Yeah. But when we talk about Pleistocene, when the environment was different in Australia, the kind of time period I'm thinking is more like 50,000 years ago. So these deposits show more of like a woodland environment.

There were trees and tree kangaroos on the Nullarbor which is null arbor, no trees now. So very, very different. Oh! Other osteoderms that are taxonomically informative. This is a segue to big skink, which came out a couple of weeks ago.

A: Oh! I just thought of a question. So when you say the osteoderm on the tail is sort of diagnostic, is it a spike shape?

K: Yeah, it's a spike.

A: Okay.

K: So there's spiny tailed Egernia. There are multiple species of spiny tailed Egernia and they're about to be split even more, but they are like…


K: Crevice dwelling. So they have this neat little trick where if they are under threat, they crawl into a little crevice, they've got like sort of a flattened head and flattened body, but they're quite chunky sideways. They'll crawl in and then-

A: The flat head of reptiles.

K: They sort of crawl into this crevice and then they basically get a lungful and inflate themselves up. And then the spines mean that a predator can't pull them out because it sort of like grabs onto the rock. So it helps them sort of get a grip like Velcro or something. It just wedges them in and then they can't be pulled out.

A: Very cool.

K:So yeah, it's a nice tactic. They can do it in like trees and stuff like that as well. But yeah, that's kind of their niche. So I'm hoping to get it to species level from the spines because some of them have more of a sort of curve to them. Others are completely straight. They are at different angles.

But the observations that I've been reading about these are fused for taxonomic description, but I don't know how thorough the people were that were looking at this character, so I kind of want to revisit that myself at some stage, but I can definitely get it to genus because they're the only ones that have spikes in their osteoderms like that.

A: It's awesome. It's always good when, even if you don't have associate material, sometimes you just need the right bone.

K: Yeah, like for… anyone works on like fossil dragons, for example, one of the features that Mark Hutcherson told me about for Pogona, so bearded dragons. Working in South Australia, there's the two big Pogona. So there's the Eastern bearded dragon, which is Pogona barbata. And then there's the central bearded dragon, Pogona vitticeps. And the one bone, if you get it on its own, that can help you tell the difference between the two is the jugal.

A: One of the bones in the skull?

K: Yeah, so it's basically, it's the back of the orbit. So it's kind of like a cheekbone that goes from under the orbit sort of behind the eye and then comes up to the skull roof.

A: Yeah. So it's sort of framing, I guess, like the back of it being where the eye socket is.

K: Yeah.

A: So it would be not circular shape.

K: Yeah. Form one side of it.

A: If you have enough of it, you'll make a circle!

K: Yeah. There's sort of like a semi circle, sort of the side of the back of the eye. And then in Pogona it's like super fat going backwards. So I can't remember which way around it is. I have to look at another reference specimen, but one of them it's…


K: Really, really broad. And the other one is not so broad and has like a slightly different shape. So yeah, you can actually tell which species you have. And I was looking at some kangaroo island material and there shouldn't be any Pogona on kangaroo island. And I found a Pogona jugal bone and I was like, Da-da!

Because they thought they were thought to have been brought to the island by Europeans at some point. But we've got them in the Holocene. So they were actually there until relatively recently. And they’re not super common. So people hadn't noticed them.

A: So yeah, we've talked about Kangaroo Island before on the podcast. It's off mainland South Australia.

K: Yeah, so it's kind of looks like it connects with Flora Peninsula, but they have cave deposits. It's more like next to the palaeo Murray kind of thing. So it's right on the edge of the continental shelf. So yeah, when sea level wasn't as high as it was now, it was sort of still quite coastal and it was a different environment. And it's got a lot of fauna in the cave deposits that are sort of similar to Murray woodland and stuff, which is kind of cool.

But yeah, it would be really nice to do more palaeoecology with squamates there as well, but gotta do the “How do we identify them bit first?” That's kind of what my talk's gonna be about tomorrow as well, specifically like, “what can we do palaeoecology-wise with reptiles?” Where are we at and what do we need to figure out?

A: Is it sort of common these days to find multiple species of skinks in one area or can you find like different species sort of in the same area?

K: So in the living fauna, definitely multiple species, even within a genus. I've done one bush blitz trip where we're trapping living animals and having to identify it's like Morethias, it's a genus of skink that they like two of them look very similar.

And sometimes if they have an overlapping range, you're sitting there with a microscope out trying to count scales and it's a pain in the ass.

A: Wow.

K: Um, and Ctenotus is kind of the same. It's like, let's look at all these various different stripes. Cause Ctenotus is a stripe skinks. They generally like grassy plants or leaf litter. And. Yeah, basically stripe characteristics. So where the white stripe is in relation to a slightly darker stripe in relation to like, are there breaks in the stripes? So it looks more like bars or is it solid?

A: Oh, herps.

K: Oh my God. And then you've got to count like eye scales as well and like ear lobules. And it's very much nitty gritty under the microscope trying to identify what this is. And no one's even really looked at the osteology of that group yet, which I'm sure is.

A: It sounds like too hard basket.

K: Yeah. So and that is going to present.


K: A lot of problems when it comes to identifying their fossils, not just because no one's looked at their osteology, but because their osteology might be very cryptic as well. Or it might not be, you know, there might be things in the osteology that help tell species apart way better than their external morphology, but we don't know that yet.

A: That would be nice.

K: It would be handy, wouldn't it?

A: Yeah, it's hard. I mean, we try not to sort of walk into science with underlying assumptions, but yeah, you can't help it sometimes because you just… Every time you look at something and you get questions, it just makes more questions, even if you have some answers.

K: Yeah. That's like, no one's looked at this yet. This could actually be really useful. And everyone's like, off you go. You can work on it. And I'm like, oh wait, me on my own? OK.

A: Yeah, you're welcome to it.

K: It's a trap. But yeah, no, there are a bunch of people in Victoria that have been busily CT scanning every single lizard and snake in Australia in the hope to build a digital reference collection.

In order to ask these questions. And that's a huge amount of data, and it's not going to be immediately useful for fossils just yet. But in terms of actually looking at osteology, it's invaluable because they can do non-destructive comparisons using geometric morphometrics or, you know-

A: Geometric morphometrics being, I guess, like looking at the 3D shape of a bone and then-

K: Getting a computer to help them tell the difference. Yeah.

A: Work smarter, not harder.

K: Yeah. Um, and it means that they can come in and do very focused subjects on like target animal group.

A: And this would have implications for, I guess, like species conservation as well.

K: Yeah. So they can look at intraspecific and interspecific differences. So they might look at does an animal's skull shape change through its lifetime? Is skull or bone shape different between populations of the same species?

Or do multiple species have the same skull, in which case it's gonna be a nightmare when we get to the fossil record. But these are all questions that can be answered using these digital data sets where they can scan a whole bunch of stuff and then they can put landmarks on them and then a computer can look at distances between landmarks and tell them if.

A: Yeah, landmarks as in like, I guess you kind of, it'd be like if you had a fossil in front of you and then you put a bunch of like colored stickers on it and then it's trying to track-

K: So where does this bone join with this bone? Put a dot on it and then repeat.


A: And then seeing how that changes across the different groups and stuff.

K: But it's a statistically rigorous way of examining variation in shape.

A: Not just eyeballing it and being like, I think it looks like this. No, that way I suppose you actually have some hard data to say, yes.

K: I'm an eyeballer. So it's like, I watch people doing GM and I'm like, that's fantastic, go you.

A: I'm happy for you.

K: Yeah, I'm happy for you.

A: It's not for me.

K: But like, because I ultimately want to, I'm doing taxonomy where n equals one. So if you've only got one specimen. The geometric morphometrics can tell you that it's different from everything else, but generally we've already noticed that.

So we can describe how it's different from everything else. But if you've got thousands of specimens, it's not worth CT scanning all of them and using geometric morphometrics from the beginning. You can generally pick out what different morphotypes are there based on the combination of features like Marcy did.

And then maybe you'll find like, hey, there's actually, I keep seeing the same thing that looks the same throughout the deposit. I don't know what it is. It might be an extant lizard, then you can start using those methods to compare them. But up until that point, we don't really need to do that.

A: Or you haven't sort of done that in sort of your own research.

K: No, and I think it's, I think that the energy in to GM, because it is very time consuming and it produces heaps of data and it's super useful for like interpretation and validation of a lot of the sort of assumptions that I might have when it comes to identifying stuff, because it takes that length of time, I think it's better off like as an end stage of the overall analysis.

So for me, what I've been doing recently when I went to the Field Museum in Chicago is basically doing some bone sorting, pulling all the stuff out and being like, right, what have I got here?

How many different things are actually gonna be in this deposit? Can I get rough identifications on them? And then literally by putting them out in front of you on a desk, you can tell, right, well, this morphotype turns up a lot. This thing, which looks the same throughout the deposit, throughout multiple different deposits.

I don't know what it is, but I know that it's different from everything else.

A: Group A.

K: Group A, and then Group B and Group C, and you can separate them all out. And then later on, you can take photos or micro CT scan the best representative specimen for Group A and then figure out what it is compared to extant stuff. So that's kind of where I'm at and why I haven't used GM yet.

A: Oh, that's fair enough. And then, yeah, I mean, you recently had a paper that came out this year.

K: Yeah.


A: Mega chonk.

K: Yeah. The paper that took so long was one of the chapters of my PhD, which I submitted in 2019 and I graduated in 2020 in the middle of COVID. So I didn't get a ceremony or anything.

A: Oh.

K: Yeah, sadness. That's such.

A: Find you a puffy hat.

K: I have a certificate that I haven't even got framed yet. But-

A: Well, you have the satisfaction of being called doctor.

K: Yeah, I get the title, so that's fine. Yeah, so it was one of the chapters of my PhD. I'd been working on it since 2016 with a bunch of other people from the Flinders lab.

And Mark Hutchinson, my supervisor, who had found two pieces of this lizard before and worked with other people to describe them originally as two completely different animals. And so Mark loves this animal because it was weird. So it was originally described as a Aethesia frangens based on a partial sort of like half a mandible. So a dentary bone and part of the coronoid, which is sort of the site for muscle attachment that goes up to the skull.

A: So like the hinge for the jaw.

K: Not, the hinge that's further back.

A: Oh, okay.

K: But the coronoid is where the muscle attaches to pull the jaw close.

A: So it's got like a window.

K: That's like a triangle.

A: Oh, okay.

I'm wrong again. Hey, it's Adele. I just wanted to let you know that you finished listening to part one of this episode, but don't worry. Part two is coming right now. I just have to explain a couple of things.

So the first part of this episode was recorded in person at Boola Bardip or the Western Australian Museum during Palaeo Down Under 3 big palaeontology conference and we decided to try and finish off this episode virtually. Okay so if you hear a difference in the quality of the sound then that's why.

A: This is Pals in Palaeo. Again, this is part two with Dr. Kailah Thorn. So I managed to edit out a lot of some of the background noise of when we recorded at Boola Bardip, but there was a really annoying squeaky automatic door because we were in a shared public space.


A: And then after battling through forWhat felt like an hour, we decided that we both had enough and then we decided to go to the pub, which was an infinitely better decision to make. But we are back for part two.

We're gonna talk about MegaChonk, Tiliqua frangens. And yeah, it's actually been a couple months since we saw each other at PDU3. But I think as it turns out, we're gonna see each other again at another Aussie palaeo conference, CAVEPS.

K: Get excited. I'm super keen. Yeah, so I submitted a proposal for a themed symposium at this year's CAVEPS, and apparently it got up. So yesterday, the third circular came out, and there will be a palaeoherpetology symposium at CAVEPS, which is basically everything that is good about very, very dead reptiles and amphibians.

And when it was sort of announced in the circular all of a sudden I've got all these messages flooding my phone and that's it's not an understatement. I had like four or five messages come in being like, “Oh how do I get into this symposium” and “I'm like uh great question” because abstract submission has closed um but apparently it's happening so hopefully enough people submitted palaeoherpetology themed abstracts.

But yeah, it should be exciting. There's, I know quite a few people that I spoke to before abstract submission closed, that are going to be talking about really neat reptile and amphibian fossils from across Australia.

Some of them have updates on PhD projects. Some of them have started new things. Some of them are giving us neat insights into some New Zealand things and things that students have done. So it should be a pretty diverse session, I think. So, so far I've heard whispers of, everything from skinks to sea turtles to giant mesozoic amphibians and things. So yeah, it's all coming together.

A: I just… I don't know why I didn't think of this before, but that might even include me because I submitted an abstract.

K: Yeah, I think it'll be interesting to see what everyone's thoughts are on including dinosaurs in herpetology because they're not traditionally thought of as herps.


K: Like at an SVP conference, because they have their own, their whole own area. But in Australia, there's not a lot of people working on dinosaurs. So I suspect they might limit it to traditional herbs from the original sense of herpetology, which is creepy crawlies. So it'll be modern style.

A: Stuff that is actually still around to find alive out in the wilds as opposed to can't be doing that with dinosaurs.

K: Yeah. Or not necessarily. It'll be like. I think they might include squamates and amphibians and turtles and crocodiles, I suppose. But we'll see. It will depend on the diversity of talks, I suppose.

We can fit all the reptiles in or there might be another big batch of dinosaur talks and you guys will get a themed session to yourself. But yeah, I'm excited to have everyone be hyped about palaeoherpetology because usually at a lot of these conferences it's one of the probably less well subscribed sessions and very few talks. So, um. It'd be nice for everyone to get together and be on the same page.

A: It's also just really good when you have people together that work on related, like loosely related groups around and talking to each other, because you touched on SVP, the Society of Vertebrate Palaeontology. The way their conference roles is, yeah, no joke. There's like three dinosaur sessions, I think, going on maybe at any one time. No, that can't be right.

K: Yeah, I think they're on three different days and it's like, it might even be at any one time there is a session on or at least a mesozoic reptile session.

A: There's a lot. Yeah. Crocs and pterosaurs were lumped together, but it's interesting because there's some convergent evolution between like some of the jaw shapes and forms of crocs versus pterosaurs. I don't know. It's just really good to sort of be out of your bubble a little bit and hear what other people are working on be able to, I guess, take learnings or methods from other groups and then apply it to your own.

K: Yeah, I think one of the best things about CAVEPS is because, I mean, being a relatively small conference, I think they don't usually get to 200 people. It is quite small. It's great for networking because of the intimacy of the group, but also there's no concurrent sessions. And it's kind of almost been an unwritten rule that CAVEPS is always just...


K: It's always one big room and every student is presenting on the same platform as every professor, to this, you know, theoretically to the same size audience because no one's really ducking out into the foyer to work on something or to sneak between two different sessions based on which is going to be the more popular talk.

So it's a really good platform for early career researchers, for networking and for being able to present to everyone rather than just, you know, their student peer group. And we're all pretty casual Australian palaeos, I don't think any of us are particularly uptight at all. So it's quite homey and welcoming. I'm really looking forward to this.

A: I'm looking forward to it.

K: Yeah. It'll be my first proper cave-up since like 2013, which is a scary thought, cause I realized that's 10 years. I went to the one in 2013 in Adelaide and that was great. And then I missed the Alice Springs one cause I couldn't afford to go that year.

And then I missed the New Zealand one cause I went to SVP in Canada that year. And then. The last one was SVP, but it was a pretty loose one-day workshop instead of a full CAVEPS . And then since then we've had COVID. So yeah, this will be the first full blown CAVEPS I've been to in 10 years.

A: I've never been to a full blown CAVEPS . I presented at the 2019 one at SVP in Brisbane and I was meant to, I was meant to be giving one of the early career research plenaries and I decided to take the bus that day.

And I was like, oh yeah, I'll get to the venue 45 minutes early. That should be heaps. That'd be fine. And there were climate strikes on that day. So I was like late for my own talk. It was awful. And then I had to like be like snuck into and let into the room. And I just grabbed the nearest seat next to me.

And cause I'm a bit of a dummy and I just kind of live out in the bush. I don't see a whole heap of Aussie palaeos, unless I'm at a conference, um, I was sitting next to Mike Archer and I had no idea. So that was a great time.

K: laughing

A: And then I was sitting across from Dr. Robin Beck, who was the editor for the paper that I had just published. And he kind of waved at me and I was like, “Hey dude” and then he like motion to his name badge. And I did the full on like cartoon double take.


A: I goofed many, many times, but it was all good. Um, but yeah, that was my fun experience at CAVEPS. So I'm kind of looking forward to going back to Melbourne, cause I'm from Melbourne originally and yeah, just seeing a bunch of talks about different things, it's great that there won't be two sessions running at once because it sucks having to choose between two talks you really want to see.

Maybe one is more relevant to you, but one is a good friend. And then having to sort of like choose which one's important or, you know, say to a friend, you go to that one and I'll go to this one. So yeah, I, I can't wait. I'm really looking forward to it.

K: Yeah. I think it's, it's really good because it's almost like you're forced to see stuff that's outside your comfort zone and learn about new methods or the same methods applied to a different group in a way that you might not have thought about. So I think that's yeah, that's another kind of good bonus of CAVEPS.

It's, you just sort of learn from everyone about everything, whether or not you were intending to do that. And it kind of broadens your horizons a little bit.

A: Oh yeah. I've felt the same way with PDU3, being able to hear so much about invertebrate palaeontology, which I just don't get a lot of these days. It was awesome.

A: And you were saying that like you had that moment with… Robin Beck where you were like he sort of pointed at his name badge and you're like “Oh my God”, I had that at my first CAVEPS with Natalie Warburton.

A: OH!

K: Yeah, because when I was doing my undergraduate one of our lecturers Dr Jamie O'Shea, he taught most of pretty much all of the osteology component of our zoology major. So we did three weeks of practicals looking at, actually might have been more than that, might have been more like five or six weeks, and looking at bones, which is why I eventually became a palaeontologist, because I loved that.

And he kept talking out in his lecture slides, which at the time were overhead projection sheets. And I'm not that old, he was just quite old fashioned. But he had all these overhead projections sheets that were figures from Natalie's PhD thesis. And he actually had one that was just like the cover page of her PhD thesis, where he'd talk about-


K: This cool stuff that she was doing, I don't know if it's PhD or honours, but the cool stuff that she did with marsupial moles and with tree kangaroos and looking at the evolution of tree kangaroos and how their bones were so different to, you know, like, regular hopping around kangaroos. And I just thought, oh man, this woman is amazing.

A: You were exposed to her work.

K: I was exposed to her work and he talked about her all the time and then… I went to CAVEPS in 2013 and I'd signed up for a natural history illustration workshop and I mean it was taught by, you know, like Trussler and Co. So they were, you know, there was the people teaching the workshop were, you know, pretty amazing.

A: Trussler as in Peter Trussler.

K: Yeah. And then we had, I'm pretty sure it was Trussler who taught it, which was amazing. And then I sat, but before the workshops even begun, I've sat down at a desk and we've got, you've got to write your name tag and then stick it to your shirt.

I've written my name tag and stuck it to my shirt and there's one across from me he's like “Oh Kailah! I’ve heard all about you” and I look up and it's like Natalie Warburton's on her shirt and I was like, “Oh my god Natalie Warburton knows who I am!”

A: laughing

K: And now we're really good friends so it's really weird to think about it like that but that was yeah chill it was to hear about like she'd heard all about me from Jamie as I'd heard all about her from Jamie and it was just really kind of cool to have this very informal introduction across the table in a workshop where we got to draw cool skulls and skeletons and stuff.

A: And chat as well I'm guessing because you two would have had heaps to talk about.

K: Yeah yeah it was really good and I mean Natalie is a fantastic illustrator so I think she sort of started that class just sort of to refine her skills a little bit and I was a complete noob but the workshop was really good my artwork ended up looking like art so that was nice.

I think I still have it some ways like a wombat skull that I did but yeah and it was such an informal setting in that everyone was sort of given tasks to do so our brains are sort of preoccupied with doing the illustration and so the talk was very casual it wasn't particularly academic but it was still you know, we're talking about what we're doing but it was in a very informal setting and people was interested in what everyone's doing but not asking like hard questions that you get after giving a talk for example.


K: Or a thesis examination or something like that. So yeah, it was a really good way to meet people. And I think this CAVEPS will be very similar whether we signed up for one of the museum collection tours or there's like a molecular biomolecules workshop and stuff like that happening this year as well. I think they'll have the same kind of vibe. It'll be a really good way to just meet people as well as getting some hands-on skills. So yeah, I'm looking forward to it.

A: Yeah. Even with, I keep talking about PDU3, because it was one of my highlights for the year. Even going around and we were allocated groups and going around Boola Bardip and seeing the collections at the Western Australian Museum, it just gave you the opportunity to be pulled out of your friend groups and just have the chance to randomly bump into someone and then have a really great conversation.

But you were doing an activity? I don't know. It was… It was really great. And then the collections at WA, at WAM are fantastic. I didn't get to see everything, but I'm really looking forward to being back in Perth and really like having time to go through it.

But then like maybe seeing some back of house stuff too, because I think you've got a couple of pterosaurs and some dinosaurs and stuff.

K: Yeah. I think the… I mean, all the dinosaur material from here is on display.

A: Um, Ah, okay. Already seen it. Tick.

K: I mean like, WA dinosaurs, other than the footprints, aren't exciting. But yeah, there are, I think there's some more footprint stuff behind the scenes, like casts and things, but yeah, there are some pterosaurs in the collection, which would be pretty cool. Most of it's probably been worked on or published, but there might be some fragments that haven't or...

A: Yeah, nah, I think it's all been published. But we're not here to talk about that. Before we, I guess, sort of move on from CAVEPs, we should say it's like late November. Does that sound right?

K: Yeah. I think it's the last week in November. And then I'm going to a herpetology conference the week after that.

A: Awesome. It's all happening.

K: Yeah. I'll be going up to Queensland.

A: Oh, just heading all around Australia.

K: Yep. I'll be in Adelaide the week before CAVEPs to see everyone. And then CAVEPs in Melbourne for a week and then Townsville for the Australian Society of Herpetologists meeting.


A: Awesome. Um, can I pick your brain and ask if you're going to be presenting at the palaeo herp conference in Townsville at all or?

K: Uh, I'm hoping to.

A: We're going to hear about Tiliqua frangens?

K: Yeah. Well, I mean, I think everyone will have seen the paper for Tiliqua frangens, but I think my plan, and this is going to be quite a lot rather loose cause I haven't written the abstract yet. Um, this is, you know, how these things go.

A: Oh, deadlines due in 48 hours. Oh, I should probably start.


K: Yeah, laughing a bit like that. For PDU3 I think I put mine in two days late. Yeah so for ASH I was thinking about just giving kind of like an overview of where palaeoherpetology is at in Australia, specifically focusing on fossil squamates because I think Roy might be coming to ASH so he can talk about his frogs.

A: Roy Farman, who is at… Is it UNE or is it UNSW?


A: I told you before I have trouble keeping track of different unis with similar sounding acronyms in the same state.

K: Yeah that totally makes sense. But yeah so I'll basically talk about where we're up to with fossil lizards and what they can do for modern lizard people because I think one thing that's sort of missed in the study of living lizards in Australia is, there's a lot of work on systematics and building phylogenies and looking at ecology and biogeography of all of these different, you know, hyperdiverse groups of Australian lizards, but there aren't really any fossils informing a lot of their models.

And I know that's not because they don't want them, they definitely would want them, but we just don't have the people to… We don't have the feet on the ground actually working on that stuff. So the talk is kind of to make people aware that some of these deposits exist.

There's just no one currently working on them and maybe engage like future students or just sort of get everyone's minds sort of warmed up to the idea of all the suggestion that these things can be worked on, not just by palaeontologists, but by herpetologists looking at bones.

So there's some people doing that in Victoria now. We've met some of the pretty cool students when they came to PDU3. And yeah, it's just kind of about getting more people keen on it. So that's what I'm hoping to talk about basically is where that sort of fits in.

So obviously frangens is gonna be mentioned because it's presenting all these cool morphological extremes, but the lizard itself, that species existed as this giant horned shingleback equivalent that was two and a half times the size or two and a half times the weight of living shinglebacks.


K: In the area that it lived according to the fossils that we have, that is where modern shinglebacks get their biggest. So there's some sort of resource there that after this lizard went extinct has allowed living lizards to grow to a bigger size.

And there's no real way that people would have, like they recognize that the lizards are bigger there and it's definitely, it's one of the youngest, like genetically youngest populations of shingleback lizards or bobtails sleepies depending on what state you're from.

There's a paper that says that these are the genetically youngest branch but they didn't really have any reasons for why they might be the genetically youngest branch but now that we have this fossil species there's no they don't overlap in time with living blue tongues anywhere in the fossil records so there was obviously a bit of competition going on that sort of kept them living in separate areas.

And then the minute the big guy goes extinct, it's free real estate. And now our biggest shinglebacks come from like Northern New South Wales and the Southern tips of Queensland. So fossils can tell us about what shapes our living taxa, which ultimately can feed into things like conservation and ecological management and stuff like that… so.

A: Yeah. I think you mentioned when we recorded at PDU3 that with some overseas fossils, they also have like associated material, which can help really help you work out how big this animal is because you know, you have the outline essentially in, was it osteoderms or?

K: Yeah. So some lucky buggers have their fossils like perfectly preserved in articulation or at least, you know in a nodule or something like that, you know, amazing. But yeah, for Australian squamates, we don't really have any sites that have that level of preservation, unfortunately, yet.

You know, they could be out there, we just haven't found it yet. So yeah, a lot of other places in the world have had a bit of a kickstart on, particularly things like, so the European Miocene fauna, there's a few sites where they have these really nice animals that are preserved, sometimes multiple animals in these really sort of low energy lakeside environment.


K: And you might have some lizards alongside, maybe some mammals and fish and invertebrates that lizards might have been eating at the time. And so they've got this really good idea of what that community looks like.

Like McGrath's Flat, you know, in New South Wales, there's this beautiful preservation, but they're getting a lot more reptiles in that because at the time that area of the world was warmer and wetter and they had more reptiles. It wasn't like modern Scotland. But yeah, in Australia, even though we had that similar style of environment, our continent has had a hell of a lot more erosion because it's so low and flat.

And our sites just didn't preserve in the same way. Riversleigh is about as close as it gets and they are getting a beautiful articulated and associated material of reptiles out of Riversleigh which is like Egernia gillespieae that I've spoken about previously.

But yeah, I mean one site is fantastic or one locality I should say because Riversleigh’s multiple sites.

And McGrath's flat is exciting and I'm really hoping that at some stage Matt pulls a lizard out of the bag and says, “Kailah, can you come and look at this?” And I'll be like, “ah!” But yeah, it's, it would be fantastic.

A: That would be lovely. That makes a lot of sense because they've got insane like spiders and insects and stuff and what else is going to eat them other than each other?

K: Yeah, exactly. I mean, probably birds. They've got a feather and they have fish, but you know, like a frog would make sense from that site. A lizard would make sense from that site and I'm not expecting there to be like you know a shingleback or a goanna but there should be some small non-descript lizard or something like a water skink or some sort of little water dragon relative style thing going on.

It would be in that environment and I'm just really hoping and this is going to sound more but I'm hoping it died in that environment. That would be superb.

A: That'd be great. You're going to die anyway. You might as well be useful while you're at it.

K: Exactly. You know, things die. It's better when they fossilise. Best way to become a fossil, step one, die. Um, but yeah, so still holding out for, hopefully get something good from McGrath’s Flat, but it mean me and everyone else in the country.

So yeah, there's opportunistic places around Australia. I think salt lakes in general could be explored a lot more. I know the Flinders crew just came back from another Frome basin trip.


K: And they've had a bit of media out. They found some really nice, um, they found an associated or an articulated, uh, total carapace, which is very exciting. Cause that's like, that's, that's quite old.

A: That's the top part of the shell.

K: Yeah.

A: And then the plastron’s the belly.

K: Yeah. I got happy snaps from some of the crew. And then I saw that the local like station management group had posted a few photos on social media of them excavating it, which was really nice. Yeah. So there's, I think lakeside deposits. Uh, definitely, Salt Lakes are a really good resource for palaeontologists, but it's a lot of ground to cover and it's not a particularly nice place to be in the sun, as you can imagine. So, it's tough going field work-wise, but I think a lot of our Salt Lakes are very old, it's a low energy environment.

A: High effort, higher reward.

K: It's just a bit more… random exploration of salt lake deposits around Australia hopefully will unearth some more material. There's a few in WA I want to get to where they've found really nicely preserved plants in some of these salt lakes and you know they've been collected not particularly well preserved unfortunately so they've sort of disintegrated, but it shows that if plants can be preserved for however long, they haven't even been dated these sites yet then maybe they could be vertebrates as well.

Adele Pentland (01:04:41.346)

A: Awesome, well should we talk about Tiliqua frangens?

K: So, what are we covered so far? So I mean, we chatted about-

A: we kind of talked about how it's maybe twice as big as Tiliqua that's still around today in the same area.

K: Yes. We talked about where it was from. But yeah, I suppose I can talk about how big it is and stuff?

A: Yes, please tell us how big the mega chonk is.

K: So, when we work on reptiles, we talk about snout vent length. So from the tip of the nose to the cloacal vent, which is basically at the start of the tail. So for people who aren't familiar with how big when we talk about lizards, it's specifically that measurement. We don't include the tail because various lizards have different shaped tails and it's kind of unfair when you talk about size. Also, they tend to drop them, so.

A: Yeah, okay, that's, yeah.

K: Makes sense. So we talk about snout vent length. To figure out how big the snout vent length is on a fossil lizard. When you don't have the snout and the vent.

A: We don't have the snout and the vent?

K: We don't even have an articulated specimen to sort of roughly approximate where the vent would be. So I used a huge data set of living shingleback measurements of snout vent length. Those measurements also had, that data set also had head length.

And so I could look at how head length relates to snout-vent length and if it could be used as an estimation of snout-vent length. There's a little bit of sexual dimorphism and there's a little bit of ontogeny in that like the younger specimens are slightly skewed.

But generally I think we had a data set of about more than 200 individual animals that have been measured. And the confidence on the sort of least squares regression line, which is when you do a regression line with your X and Y.

But when I spoke to Mike Lee about this, who was my PhD supervisor, who's like definitely the methods guy, Mike said “least squares regression will always overestimate your Y value”. So it'll overestimate your unknown variable if you know what X is across the bottom. So there's a different type of regression called like maximum axis regression, I think it is, or MAR.


K: which you can do not in Excel, unfortunately. So I had to teach myself how to use R in the last two weeks of my PhD. That was fun. But it's a really simple data set to learn a new statistical method on. So there's only two variables.

But yeah, so the maximum access regression actually gives you a better estimate of your unknown, your Y variable. And so I used that method for these guys, which had a much better correlation. The data looked a lot more feasible.

The prediction error was considerably less when we calculated that as well, which was recommended by reviewers. So, we used the head length to estimate snout vent length and the head length was, I can't remember if it's the top of my head, over seven centimeters long.

When we extract, when we plot that in the same graph as our data set of 200 living shinglebacks, it turns out that Tiliqua frangens genes was conservatively 57 centimeters from snout to vent.

A: So that would be a head of two and three quarter inches. And then the whole body would then be like 22 and a half inches.

K: Yeah. So once you include a tail, if it has a sort of stubby tail, which living shingle backs do, we're probably looking at a lizard that's about the length of a human arm, from fingertips to shoulder.

A: That what? That's nuts!

K: Pretty decent size shingle back, a very decent size shingle back.

A: There are goannas that are about that big.

K: Yeah. Yeah, there are, but it's heavier. It's chunky.

A: Oh yeah. It'd be hefty.

K: Like goannas are like greyhounds. They're racehorses, right?

A: Slender. Yeah.

K: So shinglebacks are like staffies. You know, they are built like a brick dunny. Um, so to use a bit of Australian slang, but they are very solid. Like I've seen shingle backs that have been run over by a car, get up and walk away because it is like, um, you know, they can't use their back legs for a few weeks, but after a while they're all good.

And then since I'm gnarly broken, pelvis is on shingle backs and they've just fused and carried on with life. I've been hit by cars like it's wild.

A: What? Oh my gosh. These are indestructible. So how did Tiliqua frangens…


A: Why do we think Tiliqua frangens went extinct if they...

K: Are so indestructible?

A: Yeah, if they can go toe to toe with a car and...

K: It's a great question and we don't really know the answer because in the sites where we have them, Cathedral Cave at Wellington was the main sort of drive for me to work on this because it was being systematically excavated and identified by Diana Fusco at Flinders University and so much material for this lizard came out of that cave excavation.

But so we know roughly the time it disappears and we will eventually have the full story of what's going on ecologically at that site. But for the other sites it's not as detailed in terms of what's been going on, well it hasn't been published yet. So we can't sort of pinpoint exactly when, where and why it's going extinct at the whole species level.

When it goes extinct for Cathedral Cave is about 47,000 years ago. So its last occurrence is in the same layer as the last occurrence of the Australian megafauna in that deposit. So it's come to a similar demise as the other Australian megafauna.

It just basically becomes another one on that hot list of species where the debate sort of seesaws between climate and environmental change and the arrival of humans or disease or combination of all three where you can't really have any single smoking gun because there's multiple smoking guns at different sites it's a lot more complicated answer than that.

But for shinglebacks like this guy I mean modern shinglebacks are a food source for different indigenous communities but you know this guy was considerably bigger that's a good amount of food man and it's covered in this bony armor plating it's effectively coming in its own bowl like you bop it on the head flip it upside down and put it in the coals. I mean, I don't know how these things work, but unless there was something particularly off-putting about the flavor, it'd be a good eating. So-

A: Yeah.

K: It'd be silly not to. But yeah, we don't have any archaeological evidence. I haven't heard any stories or anything about this kind of stuff happening with this particular animal. But it would be interesting to find out if there's any stories or knowledge passed down about this particular species. We've heard stuff about diprotodon and other megafauna from different songlines.


K: From three different groups, but nothing about this guy yet. So it may or may not have had an important sort of role or been a food source, but yeah, the timing is pretty coincidental with the arrival of humans in that area.

So yeah, that might be a reason. So it definitely wasn't around with dingoes. And I think in terms of what its natural predators may have been really. For living shinglebacks, it's things like big birds of prey, predominantly eagles, will flip them on their back and unzip them because their scales underneath are slightly softer.

A: Oh, I thought they were going to do the pick you up, drop you type of thing.

K: They probably do that to stun them, yeah. But I think it's, yeah, they generally they'll unzip lizards from underneath because it's easier to get to them and they can hold them down and the head can't bite them. And we've found quite a few carcasses like that at it Frome Basin sites.

So. Yeah, underneath Wedgetail Eagle Nest, so that was pretty cool, taphonomic information. But yeah, so they might have been unzipped or maybe picked up and dropped or thrown against rocks and things like that to sort of knock them out. There were giant eagles and vultures in Pleistocene Australia that were around and living at the same time as this lizard, so that's a possibility. Otherwise, I'm pretty sure a Tassie Devil would give it a pretty good going.

A: Oh yeah.

K: They got jaws built specifically for bone crunching. So I don't think the bony armor of Tiliqua frangens would have been enough to protect it from a bone crunching Tassie devil. And these are slow animals. It's not really much of a hunt, but it would definitely be, you'd want a group of Tassie devils, I think, to take down one of these if they were going to, because if you get bitten by the jaws on this lizard, you're in for a bad time.

A: Yeah.

K: You get bitten by a living shingleback and it hurts and they are quite muscly. And this guy has next level muscle attachment scars on its jaw bones. It has deeper, thicker jaw bones and muscle attachment sites on the skull bones as well.

So we haven't done any bite force estimations yet. That's something I'd really like to do, but it's, it's going to be packing a punch much heavier than living shinglebacks, which have got an insanely strong bite. So yeah, that's something to think about.


A: So what are they doing with these like really strong jaws? Are they… What are they eating?

K: Yeah, so that's also kind of speculation at this point now. The only thing we could really say is from looking at the teeth and they're comparing it to teeth of living skinks. So shinglebacks predominantly are vegetarian and they'll like sort of opportunistically eat carrion that they can, they stumble upon. So I've found like half a bird humerus in the stomach contents of a shingleback before.

But in the summer, you'll see them walking through a field of daisies. And it's quite picturesque. Like, it's basically, it's a field of snacks for them, right? They walk along and push over the daisies with their head as they walk along. And then as they get to the end of the daisy stalk, they bite the head off and they eat the flower.

A: Oh, so they want the sweetness.

K: So it's just using like brute force.

A: Yeah, right.

K: Yeah, so they just like brute force will just sort of push over all these tiny little plants and bite their heads off. It's quite cute. And then yeah, they would be doing the same thing. So feeding on little succulents and succulent flowers. That's a lot of their diet.

Otherwise, yeah, opportunistically eating carrion. So if we know that that's what modern shinglebacks eat, and we look at the teeth of modern shinglebacks in the jaw structure compared to frangens, frangens is very similar. The teeth are slightly thicker and a bit more robust.

The cementum that's holding the teeth to the jaw or in the jaw is ridiculously overdone. There's so much more dental cementum to the point where in a lizard where most of these guys you can see the teeth are plastered to the side of the jaw. So that's basically like their mode of tooth implantation.

These guys, they've got so much dental cementum. It's actually grown over the front of the teeth and it looks like they've got teeth sitting in bone now.

A: Oh, okay. So I don't know, like to use an analogy, if it was like Lego bricks, I guess maybe, it would be like if someone smeared like a layer of other stuff around the Lego bricks.

K: Yeah, kind of. The tooth reinforcement is next level on these animals.


K: And they've got a bit more strength in their overall shape, but they still have a point at the tip of their tooth, which is exactly like living shinglebacks. And so generally speaking, when you've got a little point and then a big wide tooth, the small point is used to break surface tension of a hard object, and then the width of the tooth is used for crushing.

So in snail eating specialists, so the pink tongue lizards, which you'd have up in Queensland as well, but mostly probably on the other side of the Dividing Range to where you would be.

Pink tongues have one really, really big tooth at the back of their jaw that has a tiny little pointy bit in the middle, but otherwise it's big, round and flat. And the pointy bit, when pressure is applied to a snail shell, the pointy bit is where it first breaks.

And then once you've got a tiny crack, the strength of that shell is negligible and the rest of the tooth can crush it. And so the same kind of force is applied with these teeth in Tiliqua frangens. So it’s got a point at the very cusp and then it's rather thick.

A: Oh, okay.

K: Yep. And so it's using, it's breaking into something or crushing something that needs to be cut first. So we jokingly suggested maybe some sort of melon, which, you know, the idea of Tiliqua frangens walking around the ground eating paddy melons was sort of a cute theory, but yeah, they could have been some sort of ground based vine fruit or succulents that were quite tough on the outside because the area would have been semi-arid to open woodland. So yeah, some sort of tough ground-based fruit or succulent.

A: Can they climb?

K: No, they're definitely not climbing. I've seen a blue tongue climb up a security screen. They can do it when they need to because they've got claws.

A: Yeah, okay.

K: But they're not built for it. They're not made for it. They'll climb up to the top and go, oh no, now what do I do? And then just let go, let gravity take over the place and then walk off as if nothing happened. So, yeah, they're a bit, they're not climbing lizards. They're just sort of, yeah, they're little bulldozers and they're like relatively slow. They're not in a hurry to go anywhere. They're covered in like spiky armored plating for defense. It's like a, it's a tortoise. It's a tortoise. If a lizard evolved into a tortoise.


A: Bulldozing flowers.

K: Australia doesn't have any… best interpretation basically.

A: Yeah, yeah. Best impersonation of a tortoise. Because we don't have tortoises here in Australia.

K: No, not land-based ones. So this is kind of our equivalent. Pretty much every other continent other than Antarctica for obvious reasons has a land-based like small to medium sized herbivorous tortoise that loves that inhabits a lot of their like sort of woodland or desert areas.

So there's like African spurred tortoises, gopher tortoises, and Australia doesn't have that. We had Meiolania, but that's way bigger and would have been doing something entirely different. So that niche was free real estate. And these lizards were like, well, I mean, I can do that.

A: I'll give it a crack.

K: And so they did. And they did it in their own special way. Yeah. And I think they did a pretty good job. And that's pretty much what shinglebacks do now. They move slowly, they live in open habitat. They don't really have any particularly prevalent natural predators.

Like animals will give them a go if they absolutely have to, but they tend to just not bother. And I think it would have been the same for Tiliqua frangens. You know, its bite was definitely worse than its bark. And it's covered in an unappetizing layer of thick spiky plates. So not worth the effort.

A: I was trying to have a read through the paper before we hit record. Uh, Tiliqua frangens. It's, is it known from multiple specimens or do you just have the one?

K: Uh, multiple from multiple sites.

A: Yeah. And multiple like ages.

K: Yeah. So basically Cathedral Cave, that deposit at Wellington that Diana was working on was really sort of like kind of like the Rosetta stone for pulling all the other pieces into the story. So, Cathedral Cave had multiple pieces all coming out within, you know, single layers.

They were relatively well preserved. And then the other pieces that had been previously described by Mark Hutchinson and John Scanlon and Andrej Čerňanský, I was able to pull those into the story by finding, you know, the same elements in the Cathedral Cave deposit. So now we know it's concurrent in time and space.


K: And then, some of these bones, there were so many of them representing various sized animals and there was a slight variation in shape and it actually maps pretty well across like an ontogenetic trajectory. So we've got smaller jaws that have no wear on their teeth.

They have no growth scars, no fusion of their bones and no tooth replacement and their shape is similar to neonate, so like sort of unborn or very recently born shinglebacks. So we were like, oh, we have a neonate of this fossil species, which is really cool.

And then you can see these sort of shades of grey changes to these like sort of dental bones from this neonate completely unworn teeth to the first few teeth being replaced through to muscle scarring becoming thicker and the bone becoming thicker and they've got like a little chin bone that sort of comes out at the front of the jaw to meet the matching jaw from the other side to reinforce the front of their jaw bone.

And you can see them sort of grow into it. It seems like this really weird little nubbin when they're babies and then as they grow older the bone becomes thicker and just looks like the rest of the jaw. So we've got an ontogenetic series that sort of ties in these different life stages and now we know that the smaller individuals are not a different species they're actually just babies of that species which was very nice because otherwise they did look quite different.

And then once we had a really good idea of what the material looked like from Wellington I was able to recognise it in other collections around Australia. So the Australian Museum had a lot of the original material collected from Wellington Caves and they just had it sitting in the drawers, this giant skink bones and they've been sitting there since the late 1800s and people had slapped Varanus question mark on it thinking it might have been a goanna or I think there was like a possum humerus in one of the boxes.

It's just there hasn't been a lot of people particularly interested in fossil lizard bones until recently and so this wealth of stuff was just sitting in museum collections waiting for me to come along and go “Oh my god”, so that was exciting.


K: Queensland Museum, I, told Scott Hocknell that I was coming up to visit. And I told him what I was looking for. And he was very familiar with the earlier publications that had come out describing individual bones from this animal. And he's a fossil lizard guy. He'd worked on fossil dragon lizards.

A: Oh!

K: Yeah. So his honors project was on fossil dragon lizards.

A: My gosh.

K: He worked, he's worked on-

A: Really?

K: Yeah.

A: Okay. I thought his earliest work was on gastropods and he's sort of better known for his work on dinosaurs as well. He's just one of those people that can work on anything.

K: And he just started doing stuff when he was in like high school as well, so.

A: Yeah, yeah, start young.

K: Yeah, his honors work was on fossil dragon lizards. And so Scott knows a thing or two about fossil lizards, if you ask him a question and he said, “I know exactly the animal you're looking for and I know we have it in the collection”. And I rocked up and he'd already pulled it out for me and he was like, “I've been waiting for someone to show an interest in this”.

A: Oh, wow.

K: Because he just didn't have the time to do it himself. So yeah, and he was really stoked that someone was interested in that animal, not just because it was like, oh, here's another megafauna species, but particularly because I've been looking at the rest of that group. I presented him with a holotype for Egernia gillespieae from Riversleigh already.

So we knew that I was like… he'd seen some of my work before and what I was planning to do with these lizards and stuff. So yeah, so that was really exciting that Scott was there and-

A: You know your skinks.

K: You know, you've got to know something. But yeah, so that was really cool. And then the same when I went to Museum Victoria, it was going through draws of stuff that had already been collected and pulling pieces out from various sites. So we don't have anything from Victoria, so it doesn't look like it's gone south of the Murray, but there is material from north of the Murray River.

So there’s some from Lake Victoria, I think it was Lake Victoria and some other sites that there's a PhD student at Flinders working on. So yeah, and then there was some published bits and pieces from other sites in Queensland and New South Wales where someone's illustrated this bone and said, oh, I don't know, it might be a blue tongue, might be a goanna. And like I look at publication, I go, well, it's definitely this lizard. But they wouldn't have known that without having all the material that Cathedral Cave had.


K: So, I just lucked out I was in the right lab at the right time and was able to have access to all this material and work with such a great team of people who all had these areas of expertise that together were able to basically get this paper done and get this lizard out there to the world. So yeah, it's been pretty, I've been pretty fortunate to be, have all that stuff aligned. You know, I'd be keen for another one. I've got some other projects that would be cool like that, but it'd be interesting to see if.

More material pops up in people's excavations now that, you know, might not have been recognized previously and now people might have their eye in for what they're looking for.

A: Yeah. I think hopefully that'll be the case, especially now that you've done all the hard grunt work and been able to pull, you know, the babies and the big ones together.

K: Yeah. And there's other giant blue tongues out there. I've seen fossil remains of other giant blue tongue species that are not Tiliqua frangens.

A: Oh, wow.

K: Spoiler alert. So that's cool, but it's whether or not there's going to be enough material to actually describe it as a new species, you know, do you using a single jawbone, which is what they originally did for Tiliqua frangens when it came out as a Aethesia, you can have a paper that is, we found this really cool jawbone in it, you know, this represents a blue tongue that's longer than Tiliqua frangens, but is actually very similar to an eastern blue tongue, like it's going to be long and slender and blue tongue shaped instead of shingleback shaped.

But that's a lot of speculation from a single bone. So, you know, do you wait until you find more material? If it's from a difficult site, yeah. So there's definitely still a wealth of material in collections, but a lot of it sort of starts that inquiry process rather than finishes it.

A: So the good thing about science, you start with a question, then you finish. And honestly, the further I get into a PhD, it feels like the further I get in, the less I know in a weird way.

K: Yes, yeah that's definitely and that's good like I think the further into a scientific career you get you should have more questions and definitely feel like you know less than when you started.

A: Yeah more questions.

K: And if you've gone the other way around you're not doing it right. Yeah I think when you finish honours you feel like you know so much and then you start your PhD and you're like I know nothing.


A: Yeah, yeah, I laugh. I look back at my old, my old Endnote library and at the end of honours, I was like, this is the final one. I'm like, Oh, sweet summer child. So you have so much ahead of you.

K: laughing

A: Well, we have like five minutes left. Is there anything like really quickly that we didn't touch on with Tlaquah for engines that you wanted to mention? Cause I try and normally talk about form function and family groupings of stuff. I feel like we've covered form really well. Like an arm of a lizard is like a really good visual thing.

K: Yeah, yeah. That's why we used it for the media release.

A: Ecological niche. We kind of talked about how it's, it's vibing out, possibly eating patty melons.

K: Yeah, I love that picture.

A: Yeah, possibly bulldozing big flowers. And yeah, there are a lot of modern tiliquans today. I feel like the comparisons to like normal, not normal… Extant species has sort of been like woven and informed like how you view the fossil so I feel like that's a good tie in too.

K: And likewise like I did a little bit about the function of the teeth and how it relates to the diet.

A: Yes.

K: So yeah I think and I mean like family groups is I mean I could talk about sort of phylogeny of this group of lizards was sort of the backbone of my thesis and also why I had Mike Lee as a PhD supervisor.

A: I don't think we really touched on that, but I know in part one, you kind of said you wanted to do like sort of bigger, like broad scale stuff, but then you had to do the basic grunt work of like.

K: Who's related to who?

A: Fossil IDs in a way.

K: Yeah. So like in Egernia gillespieae was the first paper for actually just sort of nutting out how old each of the groups in the Blue Tongue family, like the tiliquans tree, like how old they are, where they sit in relation to each other, and where these lizards may have come from. And then, so that was, yeah, Egernia gillespieae, and then Proegernia was sort of, how long have they been in Australia?

Can we really push the boundaries for how old this group might actually be, and how long they've been here? And then, Tiliqua frangens was really looking at what morphological extremes have these animals reached since they've been in Australia? What have we not seen?


K: We think we know everything about.this group of Australian skinks, which are Australia's largest skinks, and they're used for all of this behavioural research. You know, they're social skinks, so they're used by behavioural ecologists and people studying sociality and reptiles, and geneticists and people looking at parasites and disease because of the way we know so much about these guys.

They are model organisms for studying ecology, and yet… they just reached these extremes and did these ecological things and had these ecological roles that we just had no idea of. And it's not like this happened millions of years ago. It would still be around today were it not for some random factor in the late Pleistocene causing it to go extinct. So I think that's the main reason that frangens is a chapter of my thesis and not like a neat side project is that it really ties in and it shows us what the unknowns are.

Like, what the possible unknowns for this group. So that's kind of why we wanted to have it with a family tree. Like it looks so much like a shingleback whilst also being not like a shingleback because of its extreme proportions. But we tested it by putting it through the same analysis that Egernia gillespieae and Proegernia went through to find out where it sits on the tree in relation to the other taxa. And the first time I ran it, weirdly it actually...

branched off with the Solomon Islands monkey-tailed skink.

A: No. What? That's breaking my brain.

K: Yeah and it didn't pair off. It didn't pair off with shinglebacks and I was like, “excuse me, I think you lost friend?” And the data explaining that was that because I had continuous characters in my morphological matrix.

A: OH.

K: which are based on measurements of the bone, like actual measurements, not just, you know, you know, does it fit into A, B, C or D category, but actually comparing proportions of things.

A: It's a numeric value.

K: Yeah. The numeric value, its head shape is very similar to the Solomon Islands monkey tailed skin. It has a very tall, very broad head with a very broad nose.


K: It doesn't have a pointy, dainty nose like a um, shingleback skink does. It actually, shinglebacks have this like, their nose come to quite a point and the Solomon's monkey-tailed skink is entirely herbivorous and it actually eats foliage. It eats leaves and is arboreal.

So this animal doesn't have the teeth for eating leaves but it definitely has a head for eating plants and it has a head with a bite force for getting through tough plant material. So yeah, once I actually looked at the fact is like, Oh, hang on.

So the form is causing this sort of like fake phylogenetic signal here. If we adjust the data set to be like, hang on a minute, if we take those characters out, which are obviously skewing the data a little bit, where does it sit now?

A: Yeah. Or just tell it head shape. Maybe not the greatest, like what I think you can weight scores and stuff and do a bunch of stuff.

K: Yeah. So. I mean, it kind of sounds like you're fudging the data and in phylogenetics, a lot of the time there are creative ways in which people can and do that. But, um, it's all like mentioned in the paper. It's like, this is our first result, which was odd. This is what explains it if we take that variable out, this is how you fix it.

A: I think as long as you're transparent about what you did and why you did it, then it's all good.

K: Exactly.

A: Awesome. Well, thank you so much for talking to us about skinks cause we're coming up on time. I think you're going to be pulled away to do.

K: Yep. Stuff.

A: Some collection stuff. Yep. Watch the space for more big skinks. By the sounds of it.

K: Yeah. Hopefully if I get enough side project time.

A: Yeah. I mean, we might as well, you know, try and learn as much about them as we can. That's just, that's just smart.

K: It's only a matter of time until our skink overlords take over the world.

A: Oh, this, this is so weird. Cause I, I watched Spider-Man, the amazing Spider-Man the other day. With the Lizardman. Looking forward to seeing you again at CAVEPS and catching up then.

K: Should be good. I'm keen as...

A: Some palaeo herp goodness, yeah.

K: Alright, Well, I'll see you then.

A: Thanks so much for your time.

K: No worries.

- - -

Adele: Kailah! Wow, I... I learned so much. My head might actually explode but it was worth it and I hope you feel the same way. Kailah, again, thanks so much for sharing your knowledge on living and extinct skink species.

If you loved this episode and want to lend a helping hand to Pals in Palaeo, please leave us a rating and review on Apple Podcasts. I don't know why, but that is the number one thing you can do to help the show grow. Unless, I don't know, you've got like, 50k followers on Instagram, in which case you should tag us.

Sorry I'm getting delirious and should really eat something, but, before I do I just want to thank you for taking the time to listen to the show

I also want to say thanks to our lightning fast podcast editor Francy for editing the show and making my really loud, awkward laughter less weird.

Francy is also the lead singer of Hello Kelly also created our amazing theme music! If you want to hear more amazing tunes check out Hello Kelly and their latest album Sweet Nostalgia.

Our podcast cover art is by Jenny Zhao who I connected with through Crumpet Club House.

Pals in Palaeo will be back soon with fresh facts on the form, function and family groupings of your favourite fossils, but I have to go now, my planet needs me


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