Meet the Museum: One skink, two skink, big skink, blue skink

Arlene Moncrieff: Welcome everyone to meet the museum tonight. It's my pleasure to welcome you here. To, what's a very exciting, what sounds like a very exciting Doctor Zeus talk, but in actual fact is with Doctor Kailah Thorn, who's from our Museum Welshpool scientific team, who, I've just found out today has got a new title. So, forgive me, I have to read it out because I didn't quite put it into memory yet, but her current position is a project coordinator for the Perth and Peel Biodiversity Survey, which, she might tell us more about, or may not, it’s up to her. She will also give us a bit of an insight as to what she's been doing with her life before coming and working with us at the museum. So, without further ado, thank you Kailah for being here for ‘One Skink, Two Skink, Big Skink, Blue Skink.’ and, I'll hand over to you now.

Doctor Kailah Thorn: Cool. I'll take it away. Before I start, I'd also like to make an announcement of the traditional custodians of land in which we're talking today. But also, acknowledgment of country and the connection to country that they have. So, a lot of the animals that I'll be talking about today, very significant to different, traditional custodians around Australia. And some of the fossils I'll be talking about, are of animals that existed when the first Australians arrived here. So, they'll hold, quite a bit of significance for different groups. And they probably know a great deal more about some of these animals than we can tell just from their bones alone.

So I'm going to be talking about skinks today and I just thought I'd start off with explaining what a skink is, just in case anyone isn't quite aware what a skink is, because I've had my mum ask me that question. Doesn't normally pass the pub test, but, ‘skinks’. It's a lizard. For the [laughter] This has been my favourite meme, this is basically what goes on in my head all day.

So, skinks are lizards, specifically, because there's lots of different types of lizards around the world, skinks are generally shiny, okay? Their scales don't have.. they're not dull. They're quite shiny. They reflect a lot of light. Their scales overlap one another. Okay. Unlike dragon lizards, where, the scale is quite stretchy, their skin is quite stretchy, and they and they can have wrinkles and things like that. They have overlapping scales. And every single individual scale has bones inside it.

So, in some skinks like this one, it's lots of tiny bones in each scale. And then for these super armour plated lizards like this guy, all of those tiny little bones have formed one big compound bone, which you can see really nicely in this X-ray. So, they're, armour plated little guys. And all skinks generally, except for these ones with their giant jaw muscles, look terrible in the turtleneck because I don't have a very obvious neck. That's, kind of the standard skinky skink shape. So that's just to illustrate that point. So, skinks are my favourite lizards. I've always had a love for reptiles. It started when I was probably in high school with a minor obsession with snakes for some reason. But I fell in love with skinks, not straight away, after finishing university and not even in in university.

I went to uni because I thought I could be the next David Attenborough. So, I studied zoology degree here at UWA, actually, and then I fell in love with bones. And so, I decided that instead of just working on living animals, I wanted to work on the insides of animals. How they work. What different shapes and sizes they get to. And, you can find bones from stuff that's been, extinct for a very long time. So I went into palaeontology, and then I came full circle back around to palaeontology of reptiles.

So Australian skink groups. Okay. It's the most diverse group of vertebrates in Australia other than birds. But I think they're cheating. It's definitely the most diverse group of reptiles. They're separated into three main groups within skinks: My favourite is the Tiliquini, because the genus Tiliqua is all the blue tongues. Okay, so they're these guys.

We have bob tails here in WA that have blue tongues.

But they also have the sort of more smooth scale guys. So that's a Western blue tongue, that one there.

And that is, those are my hands. That's me, up in Leinster. So, a few hours north of Kalgoorlie on a biological survey. We also have the spiny tailed Egernia in this group, which is a pretty unique little skink. They're really common in the pet trade around the world. They only some of them are only this big, and some of them get to be this big. But the little ones make great pets so you can feed them crickets and things like that.

And Cyclodomorphus, which are known as the slender blue tongues. But there's a big one that's kind of more shaped like this in over in the eastern states called a pink tongue, because I have a pink tongue just to be different. And then this group, Sphenomorphini. It's a long word, but basically the coolest thing about this group is that there's a ridiculous number of species within only two genera. There are more genera in that group. Ctenotus, which is a very typical skink, shaped skink, it's got four legs, long tail, has, over 100 species within a single genus.

And Lerista is the same. Okay. And Lerista. These guys do some weird and wonderful things with their toes and their limbs. So, within this, a single species of skink, we have some populations that have, one toe, some have two toes, some have no limbs. And, and within that same within another species of Lerista, we have some individuals that give that lay eggs and others that give birth to live young. So, they're super plastic. They'll play around and do lots of different things with their reproduction and with their arms and legs and kind of really making scientists life very difficult. And then we have this group, the Eugongylini, which are also very stinky skinks. So once again, you've got a full set of limbs. Sometimes they'll change their toe counts, but these are the little guys that, commonly like sort of garden skinks.

So, you have Morethia around in your backyards, sort of garden and wall skinks. And the same with Menetia. These are the miniature, these little teeny tiny little dwarf skinks are really, really small. They almost kind of look black, grey or brown, that you see in your backyard. They're really common as well. So huge diversity across the group, lots of different shapes and sizes.

So, these guys being only this long not including their tail. So, we're talking maybe 4 or 5cm max, through to some of the really big blue tongues, which are, sort of more along 30cm, not including their tail. And when you include their tile, it gets up to 50 or more. So, skinks super diverse with their body shapes, which makes them interesting if you're studying their bodies. Which is what I did. I wanted to know when they arrived in Australia, because at the moment they're super, they're everywhere, but have they been here the whole time? And it turns out no. So, some groups of Australian reptiles have always existed on this landmass. So back when it was Gondwana, before the dinosaurs, we had, geckos. So, there's Gondwana and geckos. So, your barking geckos that stand up, do push ups and scream at you if you disturb them in the night. They've been here since always. They've just, but skinks haven't. The oldest fossil we have of skinks in Australia is this guy down here, Proegernia mikebulli and they come from this area here.

So, I did my PhD on fossil skinks, which is, basically you spend four years of your life focusing on one small area of knowledge. And I was based in Adelaide, just here on the map, which is conveniently quite close to where that green star is. And we did a lot of fieldwork, which involved basically picking up buckets of dirt on the side of a salt lake in 48°C in the shade. And we were on the side of the salt Lake where there was no shade. We take all that dirt back to the lab. And then we sieve it, and then we stare at all the grains of sand under a microscope, and we pull out these tiny little bones. And I was very fortunate to have a team of volunteers helping me with this. And after a while, we got a lot of these specimens. So, this is actually the lower jaw of a skink.

So, reptiles, when they die, instead of having a nice skull in sort of staying in one piece, which a lot of mammals will do, their skull breaks up into more than 30 individual bones, and that's one of them. So, we have here's a broken piece because they're never normally that complete of that same species.

And then we also have a representative from this group as well.

So, these two, this one's from a site slightly further north, Proegernia palankarinnensis I like to say that five times quickly, but I won't. These two species are from a few kilometres, a few, probably, hundreds of kilometres away, they’re from Lake Eyre Basin is palankarinnensis. These two are both around about 25 to 27 million years old. And it turns out. So that's when the first Tiliquini got to Australia. And they're both quite small, very normal. skinky shape. Four limbs, each with probably five digits and a long, thin tail. And they fit in the palm of your hand. Okay. Much like a garden skink would. And we also had things very much like garden skinks around at that time. So that's when we think they got here about 25 million years ago.

But when did they start to look like cool, very Australian skinks. When did they become ‘skinkizens’ of Australia? So, you know, taking a bit of Australian culture to do their own Australian thing? Well, we're guessing around about 15 million years ago. And I say guessing because that's when things started to look a little bit different. But just because a fossil appears at one slice in time doesn't necessarily mean that that's the first time that an animal existed. So, they could have been here much longer than that.

But 15 million years ago, in a place in Western Queensland, in a place called Riversleigh it's a World Heritage fossil site. There has been ‘Meet the Museum’ talks on Riversleigh World Heritage Area before. Has its World heritage listing because it has hundreds of thousands of exceptionally preserved fossils, and they’re preserved in, these big limestone blocks that take very long, a lot of work to get the fossils out of, so they have to blast them out of the ground and then put them in big baths of acid to get rid of all the limestone, then leave all the bones behind.

And a woman called Anna Gillespie spent a great deal of time, preparing out this very small, section of this limestone block that she found some of these bones in. So the first ones to come out were this bit here, which is sort of the upper, cheekbone with some of the upper teeth on it, but it's kind of been blasted by some of that acid because she didn't, because it was the first bone that she saw. And then she lovingly prepared out a lot of these other bits and pieces to help us create the rest of this animal, to sort of piece it together.

And so, I named it after her. Egernia gillespieae, after Anna Gillespie, Doctor Anna Gillespie, another great, palaeontologist, woman palaeontologist, in Australia.

So Egernia gillespieae is a lot like tree skinks, which, or Egernia napoleonis. And so they're about well, in Australia, they're about, maybe 15cm from the tip of their nose to the vent between their back legs. And then another 15cm maybe of tail, maybe. And these guys, spread, different shapes and sizes, different species to spread around Australia. And this is probably the first representative of that group. It's the first, true Egernia, the first of that genus.

From that same site, though, we also get members of the land mullet group. So, in the eastern states, there's a few species of a group called Bellatorias, and they also get really big, like blue tongues. Do. They called land mullets because they're very smooth scaled and they get quite long and quite chunky. And they kind of resemble like mullets, like the, fish that come out of the water. So they're quite chunky and shiny. They get quite fat. They're very cute.

And this little guy, first blue tongue, which is actually this one here with a big crushing tooth. So blue tongues are unique in that they don't just eat insects, which is what we think most lizards eat in general, little insects or skinks. Blue tongues have decided to go about something completely different. Some of them specialize in eating snails. So, if you've got a blue tongue in your cabbage patch, that's a good thing. You want to encourage it. They will also take your strawberries, so maybe keep them out of strawberries. Segregate them a little bit. They're quite happy to eat very succulent vegetation, so sometimes they'll eat, native succulents. Lots of flowers. One of my favourite facts about bob tails is if you watch them in a field of daisies or everlasting. Is it? They'll use their chunky little body to walk along and push down the long flowers and then bite the end of the head off the flowers. They're walking through like a little bulldozer. It's very adorable to watch. So, the first blue tongue appears at this point in time with its first big, big chunky tooth.

So we're starting to see some of these groups turning up about 15 million years ago. But this the title of this talk is one skink, two skink, big skink. So, when do we start getting big skinks. So, there are some big skinks in other countries, but they're from generally from Mauritius and Cape Verde. So, we're thinking off the coast of Africa. There's a big group from, a big skink from a group of Eugongylini. So, it's still very typical shape skink. But it got really big and that went extinct a few hundred years ago. So, we've never actually seen a live one. There's a very adorable statue of that skink on that island, commemorating the fact that it went extinct after people got there and introduced rats to the island. These things happen. But in Australia and the rest of the continent, we now know as Sahul, which includes, a lot of, PNG and Solomon Islands to an extent. We have, a Solomon Islands giant skink with a very long prehensile tail. These guys are arboreal. They live in trees, which is really neat. And they are completely herbivorous. They eat leaves in a tree, which is not what you would expect from a lizard.

And then we have our land mullets, our Blue Tongues, and our shingle backs or bob tails. If you're WA. So those are some big skinks. And to give you a bit of size of scale, we're going with the hand handful idea. Okay. So that's about how much of a handful these guys are. So, a handful of lizard is pretty decent. I would probably handle most of these with two hands to be honest. They have a pretty strong bite force as well, even though they're mostly eating snails and plants. And there's a proof of concept. There's me holding one when I was doing field work in South Australia. So good size lizard.

But when were they biggest? Okay. When did they really, really get actually big- big? To answer that question, we have to dig into our fossil history. This guy was described in 2002. It's called Tiliqua wilkinsonorum. This is another fossil that's named after people the Wilkinsons have been, collecting fossils from sites in Queensland for a number of years and donated into the Queensland Museum. And so their contribution was commemorated with this fossil being named after them.

And Tiliqua wilkinsonorum is known only from a small jawbone so, well, a jawbone that's comparatively small. It is not actually this big in life. This is a large adult eastern blue tongue jaw. Okay. With its little teeth. And this is Tiliqua wilkinsonorum, so it's considerably bigger than an eastern blue tongue, not including their tail. Eastern blue tongues can get to be about that long, a pretty decent size, and wilkinsonorum is obviously much larger.

But one of the cool facts about this animal is, something that we can tell from its teeth is that when you have an adult, all of the teeth are replaced, directly from underneath the last tooth. So, like crocodiles, skinks will actually replace their teeth continuously throughout their life as they start to get worn out. Tiliqua wilkinsonorum has one popping up between two tooth locations, which means that this jaw is still growing. These are baby teeth, so it's actually going to get much bigger. Well, that animal would have got much bigger if it hadn't died and fossilized. But we thank it for its sacrifice because it allows describe this species.

So, we know it's a really big blue tongue, but we know very little about its shape, or its overall size, because it's not an adult. Yeah. So, it's a very cool fossil. It's allowed us to give it a name. We know it's different from other things, but we don't know much else about the body, which is unfortunate. But we do have other big skinks. So, hang on. This is roughly how big it was compared to an eastern blue tongue. So big, chunky guy. We do have other big skinks. This is another one of those jawbones. And this one is very, very weird. The other ones, you'll notice it kind of a bit, you have these sort of like big grooves that come through here, and it's much thinner and more gracile. This is very chunky. It's a big, heavy jawbone. It's quite deep this way. We weren't quite sure what was going on with this when it was first described.

So, the authors on the paper, when it was first described, Mark Hutchison and John Scanlon, John now works in Western Australia as a consultant. He's actually a snake palaeontologist. And Mark Hutchison was the curator of herpetology at the South Australian Museum. And one of my PhD supervisors. When they first found this bone, John picked it up and brought it to Mark and said, this looks weird. Mark looked at it and says, I have no idea what this animal is. It could be a skink, it could be this weird group of lizards that we only know from South America. It's doing something entirely different to most other Australian skinks, and that's the only bone they had, so they didn't have much to go off. So, at the time they called it something, they called it Aethesia, got its own genus frangens, and they suggested maybe it should be put in, the skink group, and if it is a skink it's most likely going to be some sort of weird blue tongue, but they weren't 100% sure at the time.

So put that to the side. And a few years later, in 2013, this bone was found. It's not quite symmetrical, but it should be. The rest of it would basically make it into an upside-down T shape. It's quite fat. This bone is from smack bang in the middle of the skull. So, when you're a lizard, it's actually the roof of the skull about here. It's called the frontal bone. And it's very broad. Normally, they're much narrower at the front because you've got a narrow nose on a blue tongue. They actually come down to a little point. So, if you look at this guy, he's actually got a quite a pointy nose compared to the back end of his head. This guy doesn't he's almost as fat at the front as it is at the back. So it's actually got a big fat round nose. And because that bone is nowhere near where this one came from, which is a lower jaw, they couldn't say it came from the same animal. So this got a different name. It was called the broad headed Blue Tongue. Tiliqua laticephala

And then when I started my PhD, it was which was on fossil skinks. The first step you do is to find out what the current knowledge is about the field that you're working in, and as part of that, I got a grant to go to visit a lot of different Australian museums, including the Australian Museum in Sydney. And sitting in their drawers were all these other bones, some of which look very similar to this guy. And some of them were quite small, but they were definitely not any living species. And because I had some things that were sort of in between size, I realized that small ones are actually babies. And then I've got young adults, so sort of teenage lizards all the way through to the gnarly old man lizard, which is this guy. So all of a sudden we've got this huge volume of material that's linking everything together.

Now, those bones were sitting in museum cabinets, in museum drawers for over 150 years, and nobody had looked at them. Someone had looked at them enough to say, I think that's a lizard. And so they had written goanna on the label is definitely not a goanna. But it really brings home the importance of museum collections and looking after this material, even though it's not a, an instant, recognition of how important it is 150 years later was hugely important to what I wanted to do.

We also found other bones from the skull that we don't have. For most Australian lizards, this is the braincase that sits right at the back of the head. And it was all starting to come together. But then, coincidentally, other people in my lab group at Flinders University were excavating or re-excavating the site that these, two other first bones that we found had come from. And, in the process of doing that, we managed to find all these other bones, including some of the bones from the back, more of the face bones, some of the limbs. So that's actually a tibia. So, there's your ankle down here, and that goes up to the knee. And a humorous, very big, chunky humerus, the arm bone.

And then the coolest piece, which I actually brought, I, an example of today. So, you guys can come up and have a look at these at the end. This is one of those, scale bones that I was talking about. We call them osteoderms. Bony skin, or skin bones. And these are considerably large. So, there's some of the biggest ones we had were about 3.5cm wide. So, they are almost an exact copy of what the skull, of what the scale would look like in modern bob tails and shingle backs. We look at this guy and osteoderms, is pretty much the exact shape and size of each scale. And so, for this guy, you're looking at a scale that's about 3.5cm wide.

And then they have these weird features on them, these big spikes that come up off the surface of the scale. So, if we're looking at a 3.5cm size scale, these guys would actually be a not quite grown adult of this lizard. So, we're 3.5cm wide, and then the spikes, 1.5cm tall. And that's only the bony portion. A lot of the time, when you have structures like these that have, what we call a keratinous sheath. So, they'll be more, tough, sort of like, fingernail like texture that covers this bone. Forming an even sharper point is a possibility as well. But that's a bit of artistic license because we have no, no evidence of that shape. But that's usually what happens.

So, we have an idea of what the outside of an animal looks like, which is a very rare occurrence in palaeontology. If you see an artistic reconstruction of an animal, it's very artistic, and there's no matter how much science you put in it, you could basically make a purple dinosaur and no one's really going to say that you're wrong. They can't definitively say that you're wrong. It's highly unlikely.

But, for this guy, we're starting to get an idea of what the outside shape and surface texture is. And so we had an artist to a reconstruction. And so this is our reconstruction of Tiliqua frangens It's really neat that Katrina managed to put some of the, the inside of the mouth bones in as well. So, we know what the inside of the blue tongue mouth looks like. The whole group have blue and or purplely coloured tongues. So, I feel like that was fair to include. And we've got these really cool spikes and that really lumpy, bumpy surface texture continued throughout the back of this animal. And because we know what the shapes of the different osteoderms. look like in different regions of the body, we know which regions had the tall spikes. They're generally down the back in the middle, and which ones, where they started to get flatter and smaller around the sides.

And we even have a section of a limb that's covered in tiny osteoderms. as well. So, we know what the osteoderms, we know what the scales on the legs look like, too. So, yeah, we constructed this, this image is actually used and made from some of the photos I took outside the fossil site, Wellington Caves in New South Wales, and we've added a little garden skink Lampropholis for scale. So, this guy from his nose to about here, just after his back leg is about seven centimetres long, which is roughly how half the head is. This is a very, very big lizard. So, we'd probably be scaling this guy up a little bit.

But how do we get an idea of actually how big this is? How do we know how long it is if we've only got all these isolated bones, how do we actually put it together? Well, we had enough bones from the skull to reconstruct head length. And if you have head length, you can start to think about the other proportions of this animal based on its nearest living relatives.

So, the nearest living relative for these guys is our modern shingle back. Okay. And from our modern shingle back, there's a huge data set of these animals from another lab at Flinders University. I was very fortunate, lots of coincidences during my PhD. And they've been measuring a population of shingle backs for over 40 years. And they've got all of these measurements of their snout vent lengths. It which is from ‘booper to pooper’. They've got a whole lot of measurements of snout vent lengths, and a whole lot of measurements of head length from the same animals. So, when you start to plot head versus ‘booper to pooper’ length, you get this really nice trend line. Okay. And then when we put our head lengths of our animal up there, where is he? All the way up there. It's a little bit ridiculous. And so, you can kind of estimate that he's probably about 60cm long, ‘booper to pooper’. So, it's a significantly long animal that's most of your arm's length, and remember that's not including tail because we don't have any evidence of how long the tail is on this animal, and its nearest living relative is a bobtail. So, did it have a bobtail, or did it have a full-length tail? Luckily, when we talk about lizard length, we don't include tails because they fall off all the time, so we know roughly how long it is.

What about how much it weighs? So, we go back to that same lab group and we say, do you have any data about how much these animals weigh? And they have head length, and they have body mass. So how many grams an animal would weigh? And then once again, we can put our head length on that same plot. More, way up in space over there. And when we put this trend line on there, there's lots of fancy statistics. And I had to learn how to code in the last few weeks of my PhD, which was fun. This is actually a conservative estimate. So that trend line, I'm not going straight on that trend line. There's actually a boundary. So, I want to be one of these lower dots because I'm quite conservative, I'm not assuming that I'm going to have a giant animal just because I want it to be. And actually, from the lower boundaries of our estimates, we're at, around about 2.3 kilos, but probably the most, most normal body size for these guys as an adult, is probably three kilos, which is very, very heavy for a skink. And to put that into context of all other skinks alive today, there's a really, really big data set. Once again, I'm very fortunate that other people have done lots of other work, that talks about all living skinks and their body mass, how heavy they are, and if we're talking about how many species that's up here.

So, there are 160 species of skink that we have body mass for body weights for. And of those 160 skinks, most of them, less than two grams. So, when you've got your small garden skink in your backyard, they don't weigh very much. They're less than two grams. It's like buying one single chili when you go through the grocery. Generally, the scales don't even pick it up, free chili. Some of them get to about 250g.

There are these little blips over here between 750 and 1 kilo. These are actually our Australian blue tongues. So, when you get a really big bobtail. Okay. This one's not bad. All right. This is a this would be a big bobtail in Western Australia when you are in New South Wales the biggest bob tails are over a kilo. They get very, very heavy and just slightly bigger than this one. And so that's, that's this guy over here.

And then this guy sits way off the scale. It's a bit ridiculous. So, in the context of all skinks that we know of in the world, it's set. We had to either extend the graph to make this figure, which is super exciting. So, it's the biggest skink that has ever lived that we know about. But when did it come about? So, we've got these really funky body shapes going on in this group. We've got some things that have spiny tails. Some things are really big; some things are quite small. And when we put fossils into the family tree, we can do some very fancy statistics. And it'll tell us when these weird body shapes and sizes started getting a bit funky, and it turns out the first time it happens, in this bright red. When it's bright red, it means there's lots of change going on. Is one period, and this bright red section again: both of these occur when Australia decides to all of a sudden get quite a lot cooler and drier, big grassland expansion, open habitat.

And so, when you're a skink, you can get big, when there's bigger spaces where you can be nice and open. So, they, generally the larger animals are all herbivorous. So, lots of expansions in plant diversity, and they start to get weird and wonderful because the environment is changing and you've got speciation in this group.

But what's the Australian skink diversity like now? Ridiculous. Once again. So, we're about 470 species. Every now and then, taxonomists like the people that work at the museum, we change our mind about who's who and what we should call them. Sometimes we'll get one species and say ‘actually this is ten species’.

Another time. So, we'll look at some groups and go, oh no, actually these are just really variable. And they're all one animal, one type of animal. But at the moment we're about 470 skink species in Australia. And then from those three groups and one Christmas Island weirdo, and when we compare that to other groups, there's only 386 species of mammal in Australia. So, mammals always get it, they always get the news, they get all the conservation funding, the warm, fluffy feelings. But there's more skinks, actually. There are 114 dragons, 263 geckos. There's probably going to be another 20 geckos not long from now, heap of snakes and birds. But I say birds cheat because a lot of the birds in Australia also live elsewhere. So okay, but what am I currently doing? All right, so I did all that stuff in my PhD. I'm still trying to do a bit of research when I can when I'm not running around looking after the museum collection.

So here's me in Horseshoe Cave on the Nullarbor Plain, but I've actually been over to the Field Museum in Chicago to look at material that have been collected, from the 1950s up until the 1970s, from a lot of these other sites across the Nullarbor plane, because the Nullarbor, which is in southern Australia. So, there is the Bight, Perth is over there, Adelaide's over here. Nullarbor lost 85% of its, native mammal species since European arrival in Australia. But we have no idea if we've lost any of the reptiles because no one's been studying the reptile fossils from this area. So, we know really well how to identify the fossil mammals. And some museum collections collected skins of some of the last individuals. So, they happened to find them already deceased or they've collected them on some of the early expeditions. But we have no idea what the original reptile fauna was like out there. We don't know if anything's gone extinct. So that's one of my big research questions.

If you're interested in museum collection stuff and, and research, we're always after volunteers. So, I have a group of interns from universities and volunteers working in the collections. Now, you do have to be over 18 to work at it at Welshpool in the collections, because it's a dangerous goods site because we work with lots of pickled animals. So, you have to wait to 18 to join us for that one.

But you can also volunteer online. So if you're interested in data and collections, we need people to help us transcribe some of our very old catalogue books. So lots of old timey handwritten cursive writing, lots of shape recognition, which kids are really good at. They're really good at reading messy handwriting. It's probably because their handwriting is still messy. Right?

And I just want to say a big shout out to all the other people that contributed to this work. So, I said I had a lot of happy coincidences in my PhD, people working on sites that gave me material, and people leaving stuff in museum collections for me to access. So big thanks to all the museum collection people, and all my PhD cohort and special shout outs to the WAM- fam, WA Museum colleagues that I have, the SAM-fam, people from the South

Australian Museum and then the crew from Flinders.

Audience Member: Okay, so we've got these massive lizards, in our garden.

Doctor Kailah Thorn: Yep.

Audience Member: Everybody calls them skinks or king skinks.

Doctor Kailah Thorn: Yeah

Audience Member: They're massive like 40, 50cm including the tail. And they're black, are they...

Doctor Kailah Thorn: Yeah. Not quite.

Audience Member: Are they skinks.

Doctor Kailah Thorn: Yes. So king skinks. Egernia. So that group, so the first fossil from was from Riversleigh, So King skinks. Yeah they are. And also when they get to their really big body size, they become more and more herbivorous as they get older. And they, the big black skink in Western Australia is a king skink. They get really, really dark when you go further down south because being black helps you warm up easier in the sun.

Audience Member: They won't eat you?

Doctor Kailah Thorn: Yeah, no they won't eat you? They can bite, though. They generally don't. But if you poke and prod it enough, it will hurt. I speak from personal experience. But in over East, the skink that resembles or king skinks resemble Belatorias So, there's a lot of, they look it’s convergent evolution. They look very similar. They do similar things, but they're in, different groups.

Audience Member: How small is the smallest skink?

Doctor Kailah Thorn: The smallest skink. In Australia, the smallest ones are the little dwarf skinks, Menetia. So with their tail, they might get to maybe 6 or 7cm. Some of them, they might get maybe slightly bigger than that, but they're pretty tiny. And my favourite item in the collection, in the dry collection of reptiles that we have at the museum, someone has lovingly prepared a little skull out of, a dead, dwarf skink. And it's about half the length of my finger nail. Very, very tiny.

Arlene Moncrieff: Another question for you, Kailah.

Audience Member: Do skinks eat other skinks?

Doctor Kailah Thorn: Yeah, I reckon they would. I know that definitely for, blue tongues. I have dissected a blue tongue when I'm in the process of making skeletons for my research. They turn up in roadkill a lot, unfortunately, and in its stomach, I found some bits of dead skink, and I also found a bit of a chicken wing. They're quite happy to eat, carrion or waste like a scavenger when they can get it. So, most animals will do that if, it's sort of free protein, why not?

Audience Member: Is it possible to have a skink as a pet? And if yes, where can you get it?

Doctor Kailah Thorn: Yes, you can keep skinks as pets. In Western Australia, there's a strict set of rules around what reptiles you're allowed to keep as pets. They have to be native to Western Australia, and they have to be on the list of species that you're allowed to keep as pets. And they've actually just put out an expression of interest to expand that list of different species that you can keep. And they've put some more of the spiny tail skinks on the list. So if you want them to stay on there, you can put a comment on the DSI website where you apply for a reptile keepers permit. And then they do make very good pets. So I've had a when I was living in South Australia, I was looking after and Eastern Bluetongue for a while. And rehabilitating it to let it loose in the wild. And they're very easy to feed and look after, but their poops are very smelly. So, you have to clean the tank out and it's horrendous.

Arlene Moncrieff: Yeah, that just for those people who are probably not a lot along with acronyms that we're using, the BCA, Department of Biodiversity Conservation and Attractions, which used to be like park or includes parks and Wildlife. On their website, if you Google keeping pet reptiles in Western Australia, you should be able to find the links to apply for permits.

Arlene Moncrieff: Okay, next question here.

Audience Member: How many species, what's the Perth species count for these guys? And are they finding many new species? Recently.

Doctor Kailah Thorn: Okay, so I don't know, off the top of my head how many there are in Perth. And if you change your definition of ‘Perth’ to ‘Perth Metro’ or ‘Swan Coastal Plain’, it varies a little bit. It is quite diverse. We have, one of the most diverse skink faunas of the capital cities and the species count is decreasing very recently by at least one species. So Brad Marion, who used to have my job as a collection manager at the museum, he's a bit of a skink nut, and he's been for years saying that one of the skink species that is known from the Perth Hills, there will two of them, actually, he thinks that they're the same thing. And, they've just there's a paper going to be coming out very soon that shows that they are. So, we're actually losing one species because they're getting merged together, and that one's named after another WA museum person, John Dale. So that's very exciting, when that paper comes out.

Yeah. So that's lots of the little guys. Some of them are better known than others, and some of them, so they know so little about them that they're actually on the, list of priority fauna for us to learn more about and to keep an eye out for, for conservation reasons as well. So, there's, a little Sandplain Jewel Gecko, I think, is its common name, Ctenotus gemmula, for the Swan Coastal Plain population of that animal. We know very little about it. And they're not, commonly seen in surveys and things. So, we need to keep an eye out for those on our naturalist and staff. If you can take photos with your iNaturalist account, that's really important.

Arlene Moncrieff: another question?

Audience Member: I actually have two questions. The first one is, I'm currently studying environmental science and management. I'm just wanting to know if you have any tips on how to end up in a career where you're working with reptiles. So that's the first one. Yeah. I would like to know how you end up studying reptiles in general.

Doctor Kailah Thorn: Yeah. I think with any kind of field in science, there's definitely a lot of working hard and putting in the hours to, do well at uni. But there's also just generally a lot of persistence. Tell people that work in your field that you would like to work with them or volunteer with them. Stay in touch and network with those people. Put your hand up to help with some of the less exciting grunt work. If you can, because you're still learning when you're doing that. I spent years sitting there sorting tiny little, microfossils on trays. But that skill set meant that I got really good at actually identifying the reptile pieces, which is why I ended up going back into working in fossil reptiles from my original love of working with reptiles. So there's. Yeah, volunteer positions at universities, at the museum.

Wildlife carers as well gives you experience in handling reptiles. A lot of university graduates don't get an opportunity during their degree to handle live animals, so, working at the volunteering at the wildlife places gives you experience in handling, some non-venomous snakes. But also a lot of the lizards that come through, and then doing all the extracurricular stuff, getting your snake handling ticket, and trying to get involved with some of the, maybe some of the parks and wildlife field work when opportunities come up or things with Australian Wildlife Conservancy, they've got some really good, they do like internship programs where they cycle you through different locations and different tasks. Yeah.

Audience Member: And another question. Is there any fossil sites in WA where people can just have a look at or like,

Doctor Kailah Thorn: yeah, I get that question a lot. And it's really tough because we have, quite strict rules which apply to people that want to collect and keep fossils. In terms of just looking at them, it's a little bit easier. So, in the Perth area, there are some cool marine fossils that you can look at in Peppermint Grove. There's what we sit on the Swan Coastal Plain. And so the Tamala Limestone, which is underneath some of the big dune systems that run north south through Perth, where that outcrops in places like Kings Park, for example, and Peppermint Grove, you can sort of see some of the little marine shelly fossils, even, at, I think, it's a Mudurup Rocks at Cottesloe Beach, there's a lot of invertebrate marine fossils there as well.

For vertebrate stuff, it's pretty scarce. Unfortunately, the best places to see them, some of the tourist caves. If you want to get into caving in places that aren't tourist caves, you should talk to the Caving Club of Western Australia.

And then other than that, one of the top spots that the real keen enthusiasts go to is up in Gingin. So, there's a few places in Gingin where you can go fossicking. But the important thing about collecting or looking for fossils is you have permission to be there. So, from a landowner and native title, or if it's a business or quarry or something, because it's usually where good fossils are at quarries, you want to make sure it's safe. You don't go alone. You make sure you're wearing safe PPE, all that kind of stuff. If you find something, make sure you tell the right people, particularly the museum. If it's something really interesting, we want to know about it, and we can help you ID it.

I actually wrote an article for The Conversation, which is five tips on Collecting fossils responsibly. Have a look on that. And it shows you in each state what the rules are around collecting and looking for stuff.

Arlene Moncrieff: Another one here, Kailah.

Audience Member: With the fossils you're looking at, are any of the species that you find exist still or are they all extinct?

Doctor Kailah Thorn: A lot of them still exist. I find a lot of ‘blue tongue’ fossils, generally because they're bigger, and, when we use a sieve, to go through some of the sediment that we're excavating in, they turn up really easily. Once you get to really, really small skinks, they tend to fall through the cracks quite literally. And also, because a lot of Australian Cenozoic palaeontology so, we focus a lot, the groups that I've worked in focus a lot on reptiles or on fossils in general after the dinosaurs went extinct. A lot of the material is being looked at by people with a very mammal focused vision. So, they're looking for mammal bones. There's a few people now looking at bird bones, which is really cool, and there's a small group of us interested in the reptiles, so anything I can get my hands on is worth it, even if they're still a living species. Because what we can find out from the living species that turn up in these fossil deposits is a history of where these animals used to be, even if they're not currently living in that location, which is the case for a lot of the Nullarbor animals. So, grazing has had a huge impact on the Nullarbor. It's decimated a lot of the, surface level vegetation, a lot of the old trees and some of the treed parts of this plane aren't really popping back up anymore because rabbits and grazing animals are eating all of the, seedling versions of those trees. So, I think there's going to be a pretty big change in the reptile fauna through time and places like that, which we can tell from looking at the cave fossils.

Arlene Moncrieff: While you're here, can you explain to people who might not be aware as why that Riversleigh site is so valuable?

Doctor Kailah Thorn: Yeah. So, Riversleigh, and then the other site is Naracoorte in Southeastern and South Australia. Both of those sites were World Heritage listed at the same time. I think it's early 90s, a kind of date off the top of my head, because they record big chunks of time in really high resolution with exceptional fossil preservation. So, Riversleigh is a snapshot of time that's not well represented in fossil deposits around the rest of Australia. So, it's generally, sort of early to late Miocene. And then there's some sites at Riversleigh World Heritage Area that are actually Plio-Pleistocene as well. So, we're talking in the last few million years to a few thousand years ago, the generally the Illega-Miocene to Middle Miocene, so maybe 25 to about 12 million years, there's multiple different sites in a really small space in the grand scheme of things. So, in the space of a few kilometres, Riversleigh has multiple sites carrying over 10 million years of our, history. The fossils are preserved, some of them are articulated: So, all the bones of that animal are where they're in the same position where that animal fell, they're not crushed or flattened. So, they they're really, really nice to work with. And it's a huge diversity. So, Riversleigh is actually, for a lot of the sites that actually used to be cave. So, animals have fallen into a cave and died, or they've been collected by owls or predators and who has basically left all their rubbish in the cave. And then it's preserved in that, that cave dirt has basically turned into rock. And so, things have been very neatly prepared out of that. And then we've got really nice dating resolution. So, we know how old some of these sites are as well.

So, Riversleigh has hundreds of species that are only known from that location. Some of them are known from other fossil sites in Australia. And in those fossil sites, we might only have a single tooth from that animal, but we can identify a lot more about it because it matches the tooth in rivers or matches the leg bone or something like that. And so, we can say with some confidence it's going to be something like that animal, because it's existing in the same timeframe. It probably is a different species, but it's our closest analogue.

And Naracoorte is the cave system down in south, east and South Australia was listed as a World Heritage Site at the same time because it does a similar thing, but only in the last 500,000 years, where they're even higher resolution. So, they can get all these dates in Naracoorte so nicely, stratified. So, all of the oldest fossils at the bottom or these nice layers coming up to the top, they can be really well dated. And we get thousands of specimens that show us changes in the environment in that location through time, which helps us infer things like climate change and the effects that climate change has on these different groups of animals.

And these sites are now going to be protected forever because then our value, not just to the people that live in like it's locations, not just to palaeontologists, but their world heritage listed there have global significance.

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