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Transcript for
The Plesiosaur Hypothesis

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Blake Smith: So, tonight we’re going to learn a lot about aquatic dinosaurs – Wait! Don’t call them –

Ben Radford: Whoah whoah!

Blake: Don’t call ‘em dinosaurs. Don’t call ‘em dinosaurs, you’ll get smacked!

Ben: Don’t call them dinos, huh?

Blake: Do not.

Ben: Do not. Warning to our listeners: Do not call them dinosaurs.

Blake: Do not call them dinosaurs.

Ben or Blake: Whoop! Whoop! [mimicking a siren]

Karen Stollznow: Is this part of the introduction?


[Intro]

Blake: Hello and welcome to MonsterTalk: The show that lets science turn the light on monsters. I’m Blake Smith and together with my co-hosts Benjamin Radford and Dr. Karen Stollznow, we examine monster stories through the lens of science and skepticism. Tonight we’ll be peering into the dark waters of Loch Ness to see what science can tell us about the plausibility of a population of prehistoric plesiosaurs surviving in those depths through to modern times. Our guest, Dr. Adam Stewart Smith, will help demystify Nessie and at the same time will tell us about genuine mysteries surrounding Mesozoic marine reptiles.

[Voiceover: MonsterTalk!]

Blake: Apparently there are some people who think there’s a monster of some sort living in Loch Ness. Have you heard anything about this, Ben?

Ben: Uh, monster by, you mean strange unknown aquatic animal?

Blake: Yeah. Yeah.

Ben: I heard something about that. I’ve been to Loch Ness and I have seen some curious things. Mostly people who were looking for the Loch Ness Monster.

Blake: Did you just say Loch? [Emphasizes a Scottish accent on ‘Loch’]

Ben: Loch. Yeah, I try to, uh—

[Blake laughs]

Karen: Quite authentic. Impressive.

Ben: Well I, you know, I try not to ‘Lock Ness’ [exaggerated American pronunciation]. I think it’s actually ‘Loch’ well I, the closest I can get to is ‘Loch’. Is that right, Karen?

Karen: Yeah, you’re doing it with an American English ‘ah’ sound.

Ben: What’s the correct… ?

[Ben and Karen trade phonetic sounds]

Ben: Is there a guttural ‘chhh’ or not?

Karen: Yeah there is. Yeah.

Ben: Loch.

Karen: Yeah, it’s represented by an ‘x’ in genetics.

Ben: Can you do it for us again?

Karen: It’s Germanic. Loch. Sounds a bit welsh actually.

Ben: Loch.

Karen: Loch.

Ben: Loch. Alright, I’ll try to…Anyway.

Blake: And there’s our intro right there. [laughs]

Ben: Now that we’ve burned four minutes.

Blake: So there’s an animal not living in the lake or maybe it is living in the lake, or maybe it’s near the lake and sometimes takes a bath. Whatever, right.

Ben: Or something, right.

Blake: Or something, yeah. Some people think that there’s a giant monster living in that lake whose name I’m not going to—

Ben: That one lake.

Blake: … whose name I’m no longer going to attempt to say. And for some reason, of all the animals that they could think it looks like or see it to appear as, they most closely ally it with plesiosaurs.

Ben: Yeah, my understanding of the reason for that is the long neck. Um, other than that there’s no real, and obviously our guest can speak more to that, my understanding that the main reason the plesiosaur has been put, advanced as a main candidate is because of the supposes long neck that you see from, for example, the Ryan’s photos from 1974/75. And of course you see this sort of same sort thing from the Mancy photo in 1977 in Lake Champlain. And of course there’s the flipper.

Blake: And the surgeon’s photo too.

Ben: Right.

Blake: So historically, I mean from a, giving us the classic Nessie profile, the surgeon’s photo comes first right?

Ben: Yes.

Blake: And we know now that the surgeon’s photo was faked, so it seems likely that the surgeon’s photo was modeled to look like a plesiosaur on purpose.

Ben: Well, yeah, I mean, that actually brings up an interesting question in my mind, because you know, the very nature of identifying objects in water, particularly living objects, it’s fraught with problems. By definition, you’re only seeing a tiny part of whatever it is. And so it makes sense to people that, um, that if you’re going to see, you know, a part of a lake monster, you’d see its head. I mean, you could see a lake monster’s toe or tail or something, but most likely you would assume that you would see its head.

Blake: that’s right. So if the head could be at water level like an otter or it could be a swan like animal.

Ben: At the last Dragoncon I was actually on a panel with a person whose name escapes me, but he was sort of an eccentric fellow. And, I’ll choose my words carefully here. His position was… he and I actually had a cryptozoological debate. Apparently he was the best they could find on that end of things. And he claimed that the photographs of the Loch Ness monster and other monsters, particularly the Loch Ness monster, it was actually a giant tongue.

Blake: Wow!

Ben: Yes, he believed that what we were seeing was a picture of a tongue.

Blake: That is really bizarre.

Karen: I thought most people claimed that it has eyes and a mouth.

Blake: As my tongue does. [laughs]

Ben: Well, Blake, you drank a lot of paint thinner as a child. Let’s just be clear about this.

Blake: So he may be alone in that hypothesis or is there a school of thought that…?

Ben: No he was alone in that hypothesis. In fact, I, when he said that, I asked him to, sort of, to repeat that, because I’d never heard anything quite so strange. And I didn’t bother to refute it. I thought it was pretty much self-refuting.

Blake: Yeah it does seem like it would be. Could he, except for the Rolling Stones, could he think of any other creatures that would move tongue first throughout the world?

Ben: Well, there’s Gene Simmons.

Blake: Oh yeah! I guess rock stars, and Rock Ness tie in there.

Karen: Yes!

Ben: Wow!

Blake: Cryptozoology never ceases to amaze me.

Ben: You know, people have been talking about a creature in that lake since the 30’s. But I think my understanding is that it wasn’t really until Roy Mackal, for example, wrote a book called The Monsters of Loch Ness and you know, he would, I think he was one the first ones who put forth the idea that it was perhaps a plesiosaur or perhaps another creature that was known but thought to be extinct as opposed to positing, “You know, maybe it’s a cross between a whale and a unicorn.” So I think he was one of the first to bring that up.

Blake: Yeah, there’s such a wide diversity in the photographic—I hate to call it evidence.

Ben: The claims. Let’s go with the claims.

Blake: The claims. The photographic claims. There’s the Stewart photograph which has been debunked as hay bales with canvas on top. There’s all kinds of—almost like they call Bigfoot the Blobsquatch photos. There are just a lot of blurry photos. And the most clear photo, which again is now known to be a hoax, the Surgeon’s photo, does depict something that is plesiosaur like, but until you get to the Ryan photo with the flipper, there’s not much more to support that idea. But what’s the story with the Ryan photo?

Ben: Well, there’s a couple. There’s two main, depending on how you look at it, there’s two or three main photos that Ryan [unclear word] put out in the 70’s. I think mostly 74, 75. Uh, the first one was the neck form that you could make out of something in the water, whether it was suspended particles or air bubbles or what have you is of course up to debate, but he certainly saw a neck and claimed to see a neck. Then there was the flipper photo which, again, the one that was released to the public shows a reasonable approximation of what, the sort of flipper that we might expect to find on aquatic mammals. And then there was the dragon-headed tree stump thing, which I believe, as you were pointing out, was more or less thoroughly debunked.

Blake: Yeah. That’s the way I’ve understood it. In fact, if you look at all the evidence that we have for a creature in the loch, some of the most, in my opinion, damning evidence against there being something is the fact that you would need a large population of these animals and that there needed to be a big food source for them to eat. And it doesn’t seem to be, based on the subjects that I’ve read, enough caloric source material to support a colony of animals in the lake of the size that are described in the monster encounters.

Ben: You know, my understanding is that it generally leans toward, yes there probably isn’t enough biomass to support that but that it’s not necessarily conclusive because there are so many unknowns. We don’t know how big the creature necessarily is. We don’t know how many there would be.

Blake: But we do know there’s been complete sonar surveys of the lake and tons of photographic material and we’ve seen fewer monsters over time, not more. The more observers we have, the fewer sightings we have; which seems incongruous.

Ben: Yeah, it certainly seems paradoxical. I mean, especially when you look at the quality of the surveys of Loch Ness. One of the most thorough ones was done only a few years ago; I think it was maybe four or five years ago, done by BBC where they used GPS, they used side scan sonar. It was the most thorough examination of the lake ever and they found precisely nothing unusual or strange and I remember I actually wrote up a short piece in S.I. about that and the leader of the expedition had said that he had actually thought that they might find something. He didn’t go into it trying to debunk or disprove it. He sort of said, “Well, I kind of thought there might be something to it, but we looked at it from top to bottom and there’s simply nothing there.”

Blake: Yeah. I know a lot of cryptid fans really love Nessie though, because I think the mythical creature has become about as big an icon as Bigfoot in some ways. Nessie gets a lot of fictional coverage. She shows up in movies and cartoons a lot. I know my kids love Scooby Doo cartoons and there is several that have to do with lake monsters and Nessie, that kind of thing. So she gets a lot of air time.

Ben: Mmm hmm.

Blake: Which builds expectations, I think, so it’s probably really disappointing to sit at the lake and look for Nessie. Although I see the lake itself looks pretty nice.

Karen: I wanted to ask the question if we could go back to the evidence or claims just briefly. Ben, do you know anything about the Dinsdale video at all?

Ben: I know a little bit about it. As I recall it’s sort of a wide shot of something in the water as most of them are, um, and it’s leaving a wake. Again, there are a couple of them. I think I’m thinking of the right one, and the question has always been: Is it just a regular unusual wave, is it of course a head and neck leaving a wake trail behind it… I don’t know that anything conclusive has ever come of it and I don’t, as far as I know even the Nessie proponents admit that it’s basically ambiguous and we’ll never know.

Karen: Because it’s touted as being apparently the best video evidence that we have…

Ben: Yes.

Karen: …for the Loch Ness Monster and I’ve heard that it’s a boat.

Ben: Right, I think that’s the most likely explanation, especially when you look at again, the distance. I mean, this was taken, I don’t have the numbers off the top of my head, but it was taken from quite a ways away. And so whatever is, I mean, something is moving that, you know, it’s not a hoax almost certainly. It’s a film of something moving in the water. I don’t think most people would dispute that, but of course the question is: is it something that is unusual or a boat or um, an animal or something else like that, so…

Karen: It would be good to have access to that; I haven’t seen it anywhere.

Ben: Karen brings up a very good point, especially if you’re going to look at something like the Dinsdale film. Wasn’t it the late 60’s, early 70’s?

Karen: I think 1960.

Ben: ’60, right. Much as with the Patterson/Gimlin film, 67, the obvious question is: why is the best evidence for this forty years old, almost 50 years old now? With all the people…

Karen: Apparently he sighted Nessie many times but didn’t take any footage of that; didn’t take any photographs.

Blake: I looked at a site, it’s called Loch Ness dot org; actually it’s Loch-Ness.org. And they say that they actually got a chance to reexamine the film after they were originally refused access and that their analysis is that it is a boat. You’re right though. I haven’t seen it widely exposed if there is such an analysis.

Karen: Yeah, not like the Patterson/Gimlin footage or anything like that, it’s just, uh… Not like the iconic photographs of the Loch Ness monster. It’s not out there at all.

Ben: Right. I mean, I do remember seeing the footage itself. I’ve forgotten exactly where… It might have been at one of the conferences where someone had, whether it was a bootleg version or not, I don’t know but it was a case of where they could show it privately but they couldn’t broadcast it or anything so… I think Blake had asked about some of the Rines photo analysis in S.I. Let me just take a quick look at my book Lake Monster Mysteries: Investigating the world’s most elusive creatures.

Blake: Now who wrote that? I am not familiar with that book.

Ben: It’s by Ben… Benjamin Radford and Joe Nickell [jokingly mumbles the names]. I better do that again. That’s by Benjamin Radford and JOE NICKELL!! The flipper photo was taken in 1972 by Rines through his Academy of Applied Sciences and what happened was they released this image known as the flipper photo that did in fact depict sort of a triangular flipper that you might have seen on some sort of aquatic animal. This was touted as being, “Hey look! You know, we’ve got a photo of Nessie’s fin!” And this was sort of intriguing and this and that until two writers for S.I., I’ve forgotten their name off the top of my head, but two Skeptical Inquirer writers went and did their own sonar research at Loch Ness. In the process of doing their investigation they sent a request to the Academy of Applied Science and Mr. Rhines to see the original photograph of the flipper and what they sent them was a photograph that was basically a bunch of bubbles. It was a sort of random fuzzy dark incoate thing that looked nothing like a flipper. And they wrote back and said, “There must be some mistake. I mean, I don’t… This isn’t the photo that was published.” And they said, “Well no, the one, oh… we understand what the problem is. The one that you are referring to was retouched.” Apparently it was extensively retouched. And it was retouched to make it look like there was a flipper there.

[laughter]

Ben: In my book, it’s really quite remarkable, in my book, Lake Monster Mysteries, we have both the original and retouched photos of the Rhines 1972 Nessie flipper photo and it’s uh, to avoid anything libelous there seems to be a very very fine line between fraud and retouching.

Blake: Is it okay for us to include that in the show notes? That photo?

Ben: Sure.

Blake: Okay. Cool.

Ben: When the Academy of Applied Sciences was questioned about this, they admitted of course that in fact there had been some retouching and they admitted that the retouching was rather extensive and basically made a bunch of bubble look like a flipper, but they said that was, I think the phrase was ‘Standard Procedure.’ Which to my mind raises the question of the other Rhines photographs from the Academy of Applied Sciences.

Blake: That reminds me of all the times I see there’s on, and of course you see this on television… Television is what it is, it’s sometimes misleads because it’s trying to tell a story…

Ben: Nooooo!!! Skeptic! SKEPTIC!!

Blake: Ooooh, I know. But they see a track on the ground, or even like the blood stain on the scoreboard, they’re examining this blood stain and they draw around the blood stain with a marker and they’re like, “Okay. Look. It’s shaped like a footprint.” And I’m like, well how does that make any sense? I mean, you know, the creature steps down and spills blood on there. Why, it’s a V-shape. They’re implying it’s a footprint, the toes happen to go off the board. But if you just spill blood there’s just as good a chance that the blood could be dripping down and make a shape. It’s your mind is saying, oh that’s a footprint. And you’re filling in the blanks. It’s like a very forced version of paradolia where you’re creating manually the image that you allow to fool you.

Ben: Right.

Blake: I’m not sure if they’re aware of it or not.

Karen: So they lead to a certain conclusion.

Blake: Yeah.

Ben: It’s always much easier to find the footprint when someone points it out to you.

Blake: It is. Or if they paint a circle around it with paint or they put tape down.

Ben: If they hire an artist to really retouch it and make it look exactly what you want it to look like.

[Voiceover: MonsterTalk!]

Blake: So we’re talking today with Dr. Adam Stewart Smith and you’re currently working with the National Museum of Ireland. Is that correct?

Dr. Adam Stewart Smith: That’s right. I’m in the Natural History Division.

Blake: Excellent. So it looks like you’re working in documentation of collections?

Dr. Smith: I’m actually working on the entire collection in the Natural History Museum in Dublin with a group of other documentation officers and it’s a museum-wide project to give every specimen a number, effectively, and make the collections usable for researchers and for anybody else interested in looking at the collections.

Blake: Excellent. Well, it looks like Mesozoic marine reptiles are your passion though.

Dr. Smith: They’re my passion. Academically that’s what I study, so in my PhD and in my masters project I studied these animals and in my own time today I still dabble in plesiosaurology.

Karen: Is that a technical name?

Dr. Smith: It is among plesiosaur researchers, yes.

[laughter]

Blake: The reason we’re talking to you today is because many people who think that there is a large monster living in Loch Ness describe an animal that strongly seems to resemble a plesiosaur and we wanted to ask some questions about the lives and habits of these animals and find out what the facts are about these animals and then look at whether or not that seems like a plausible hypothesis.

Ok, so what can tell us right now from the fossil record about these animals? Did they live in fresh water or salt water, or both?

Dr. Smith: Well for a long time they were thought to be strictly marine, um, but we now know that they could actually venture into lacustrine deposits which are edging toward fresh water deposits, so around the mouths of lakes and into shallow fresh water systems.

Karen: Do salt water reptiles have any issues being moved into fresh water or vice versa?

Dr. Smith: Well, the main difference of course is the salt content in the water. So, originally plesiosaur ancestors would have been fresh water organisms and they moved into the marine environment from there. So the main issue would have been to cope with the amount of salt entering their system. So reptiles today such as salt water crocodiles and turtles have developed salt secreting glands which is a way of removing the salt from the system. You might see footage of turtles on the beach and their crying. Their crying the tears; the tears are the salt. And so it’s very likely that plesiosaurs, although we have no direct evidence, had some salt secreting glands for dealing with the excess salt in their systems. Whether there would have been the reverse situation for moving into fresh water systems, I’m not too sure.

Blake: Do you follow biology of salt water reptiles… do you look at bones mostly or do still follow the biology advances we’ve learned?

Dr. Smith: Well primarily I’m looking at the bones of the animals. Plesiosaurs are especially interesting because there isn’t really anything alive today that you can compare directly. So there are no living descendants of plesiosaurs. For example, dinosaurs you have birds which are living descendants. Plesiosaurs didn’t leave any descendants when they died they became extinct and they left no relatives so it makes it especially difficult to work out what’s going on with their biology so it’s actually quite difficult to answer these sorts of specific questions, so for the most part I concentrate on working on the bones and the anatomy of these animals and if there’s any clues as to their soft part anatomy in their osteology, in the structure of their bones, then that’s the basis for the study, is the bones.

Blake: I was listening to a Canadian broadcasting science show, Quirks and Quarks, which I really enjoy. They were talking about salt water snakes and they said that salt water snakes have to come to surface and drink rain water. That there’s like a thin layer after a storm where there’s fresh water deposits over the oceans and that’s where they come and get their water. So for reptiles this large it seems like they would have a very large fresh water requirement.

Dr. Smith: It’s, again, it’s one of these things that we just can’t really tell from a fossil organisms with no living relatives. There’s a lot of speculation in the study of plesiosaurs which on one hand it makes it quire frustrating, but on the other hand it makes it really interesting.

Blake: Sure.

Dr. Smith: And also, the study of plesiosaurs is actually quite a new science and in terms of dinosaur research, we know a lot about them, but plesiosaurs are maybe 30 years or so behind the dinosaur research. They just haven’t had this huge concentration of research effort so it’s actually… We’re just starting to look into these sorts of questions for these animals.

Karen: So why is that, do you think?

Dr. Smith: I don’t know. Why do people like dinosaurs? I don’t know.

Blake: Because they’re awesome! [laughs]

Dr. Smith: Of course they are! But so are pterosaurs and plesiosaurs and mosasaurs and icthyosaurs and all of these other extinct prehistoric reptiles. It’s just that dinosaurs seem to be picked out and I think there might be something just to do with the name dinosaur and so many people colloquially will include things like plesiosaurs and pterosaurs and all these other groups within the dinosauria but strictly speaking, they’re not. So if you pick up a scientific book for the popular public on dinosaurs they just have a token page maybe for plesiosaurs. And similarly in some of the research articles as well, there’s just not that much of a historical concentration on them. I don’t know. It’s intriguing.

Karen: Hopefully you can fix that for us.

Dr. Smith: Hopefully, yeah!

Blake: The Walking With Dinosaurs series has done a lot to advance the public’s fascination with them.

Dr. Smith: It has, and there’s also a new movie on sea monsters as well. An IMAX movie by National Geographic so I think that the marine reptiles are actually in the next few years going to become increasingly popular.

Blake: That’s why we picked this topic. [laughs]

Dr. Smith: Mm-hmm. Yeah.

Blake: From the cutting edge.

Karen: They do seem to feature in popular culture to the extent that on your website you’ve got all those toys that are available around the world.

Dr. Smith: Well, there are, there’s plenty of toys. I’ve picked up all sorts of toys from all over the place but if you were to put this, this is an exhaustive collection of plesiosaur toys, my collection. If you put this to an exhaustive collection of dinosaur toys, they’re going to be outnumbered a hundred to one. Dinosaurs still have that edge.

Karen: For now.

Dr. Smith: For now, for now. In 30 years time we’ll see.

Karen: Did plesiosaurs lay eggs or give live birth? And if you can tell, how can you tell?

Dr. Smith: There are a few groups of reptiles today, including boas, the snakes, and several groups of extinct marine reptiles such as icthyosaurs, which are fish-like marine reptiles and mosasaurs which are elongated body, almost snake-like marine reptiles, and we know that these animals gave birth to live young. They didn’t lay eggs. And we know this in extant animals, the living animals, because they’ve been observed giving birth to live young. And in the case of extinct organisms such as icthyosaurs and mosasaurs, they’ve been found with babies in their stomach region, fossilized. Especially icthyosaurs which have numerous good examples of juvenile or neonate unborn fetuses in the stomach region. The situation with plesiosaurs is actually controversial, however it seems very likely given that these other marine reptiles have evolved this ability to give birth to live young that plesiosaurs also gave birth to live young. They developed a very specialized body form for living in the water so it’s unlikely that the large plesiosaurs anyway could crawl out onto the land to lay eggs if they did. And in addition, some of the closest relatives of plesiosaurs, some [unclear word] animals called pachypleurosaurs have been found just like the icthyosaurs and the mosasaurs with the fossils of neonates in the abdominal region, so this is quite, these are quite closely related organisms; so again, it seems very likely that plesiosaurs were doing the same thing. There’s never been anything published on plesiosaurs specifically saying that they’ve given birth to live young or not. There are no eggs of plesiosaurs, for example, and there are no published plesiosaurs with juvenile in their abdominal region. But there is one specimen which I’m aware of that does show a baby plesiosaur in the abdominal region, but because it’s unpublished there’s not really much we can say about it, so we just have to wait for somebody to describe that specimen.

Blake: Where is that?

Dr. Smith: It’s actually in the USA. I’m not sure exactly where, but I’ve seen the photographs.

Blake: There’s a lot of variation of the types of animals I’ve seen labeled as plesiosaurs. Are all these variations the same species?

Dr. Smith: There were several different types of plesiosaurs. Plesiosauria is your order, so you have your Plesiosauria which is your group as a whole. Within the plesiosauria you have two subdivisions. On one hand you have the long-necked forms which are called plesiosaurids and on the other hand your other main lineage of plesiosaurs is the short-necked forms which are pliosaurids. So you have pliosaurs on one hand and plesiosaurs on the other. It gets quite confusing because plesiosaur colloquially can be used to describe plesiosauria as a whole or just that one major lineage. And so within those two lineages you have several families, and within families you have several genera, and within each genus you have several species. So there’s hundreds of plesiosaur species around the world.

Blake: Wow. So within these different various body sizes, um, and you’re saying there’s not much by way of soft tissue preservation in the fossil record, can we tell what sort of things they ate or what their caloric requirements were like?

Dr. Smith: The caloric requirements are quite difficult because we don’t know much about their biology, but we do know what they were eating. So there are several lines of evidence for determining what prehistoric extinct animals ate. The first way is to look the teeth. And if you look at the teeth you can make a direct comparison with a living analogy. So if you look at the teeth of, say, a long-necked plesiosaur, the teeth are very needle-like and sharp and they compare very well with a fish-eating gharial crocodile for example, so you can make a nice inference that long-necked plesiosaurs were eating things that gharials were eating which is fish, and then squid and things like this. On the other hand you have the large headed forms and their teeth were very similar to something like a killer whale and we know what killer whales are eating today: pretty much anything that they want. They can eat large mammals or fish. So you can have a good bet that these large-headed pliosaurs were eating anything that they wanted as well. So that’s one method of determining what the animals ate. The other obvious way is to look at their stomach contents and there are some cases of plesiosaurs where stomach contents are preserved in the stomach region and this confirms the evidence on the dentition from the teeth, and confirms that the long-necked plesiosaurs were indeed eating things like fish and squid. Squid they have hooklets, little hard hooklets on their tentacles and these have been preserved in some of the long-necked plesiosaur stomachs.

Blake: That’s neat.

Dr. Smith: Yeah, that’s really cool. And then the large-headed forms, obviously they’re bone crunching animals. You can find animals; you can find specimens of bones which have these large tooth marks from the pliosaurs still in them. Whether they were killing them or just scavenging them, we’re not too sure, but we do know that they were eating them. So we have a good idea what they were eating, but again, because there’s so much variation within the order, there’s lots of variation in what they ate as well.

Karen: And what was, kind of, the climate that they lived in, and how widespread were these animals? What was their global distribution?

Dr. Smith: They were global. So, we have plesiosaur fossils from Antarctica; we have plesiosaur fossils from the Canadian arctic and the coastline of Norway, and everywhere in between. So within the very short period during the Mesozoic, this is the time that the dinosaurs lived, the oceans were full of these marine reptiles, plesiosaurs, so they really did live cosmopolitan.

Blake: This is kind of a side. I saw you preparing fossils on your website. How do you clean away the mineral deposits from the fossil and how much of that is normally pulled away?

Dr. Smith: Well, it depends on where the fossil was found. Different fossil formations have different types of matrix so you can have matrix which is full of pyrite which is an iron mineral which is extremely hard and extremely difficult to prepare, and you can have specimens that are preserved in sandstone which you could literally pick away with your finger. So I have just come back from Portugal where they have some plesiosaurs from Angola, and the matrix surrounding these Angolan plesiosaurs is just a soft sandstone, so it’s extremely easy to prepare. So it depends on the age and the type of the matrix that the bones are found in. Some bones you can find on the beach so they have no matrix at all so they just are a three-dimensional bone which has naturally weathered out of the rock, so it depends.

Karen: And how big were these animals?

Dr. Smith: There was a huge amount of variation in the group. Obviously you would have babies of the individuals which would be smaller than say a metre. But if we’re just talking adult forms then they would range from one and a half metres up to giant, perhaps fifteen maybe even larger, fifteen metres. So if we’re talking about the long-necked forms, an animal like elasmosaurus which is one of these very long-necked forms has a neck which is half the length of the body. Most of the neck, most of the length of the animal is made of the neck, but in total the animal was about fifteen metres long, so these were really quite sizable animals. And then on the other side of the tree you have your large-headed short-necked pliosaur forms and these also could reach about fifteen metres and then you had everything in between. Just like you have all sorts of shapes and sizes of dinosaurs, within plesiosaurs you have all sorts of shapes and sizes.

Blake: One of our listeners, Sharon Hill, wrote in this question for you: The common view of lake monsters shows the animal with a very flexible neck, however there were some findings on plesiosaurs to show the neck was flexible horizontally but not vertically and certainly not capable of achieving the ‘S’ shape often drawn. What’s the latest view about the neck’s flexibility, especially how it relates to how the animal feeds and breathes?

Dr. Smith: Okay, well, when the first plesiosaurs were discovered, they were often portrayed with a swan-like neck, like sometimes arching out of the water. Some reconstructions also showed the neck in an almost snake-like posture and it was hypothesized that this was the function of the neck. That the neck would coil up like a snake and then strike out to grab a fish or some sort of squid. If you actually look at the bones in detail it’s actually very clear that they weren’t flexible at all. Each of the vertebrae, and there’s many vertebrae in a plesiosaur, but each of the vertrabrae is very tightly articulated. They also have processes sticking forward and sticking back, which interlock with each other and then on the top they have a spine. And these spines also closely interlock, and so the plesiosaur neck was actually a rather stiff rod-like structure and it certainly couldn’t coil up like a snake and it also wasn’t able to adopt this swan-like pose. Furthermore, if we’re talking about things like the Loch Ness monster, these are often depicted with the neck arching out of the water. Now, just because of physical constraints, it’s impossible to do this. If you imagine you are swimming in a pool and you try to stick your leg as far out of the water as possible, you simply can’t do it because you’re displacing your mass and your body moves below the water. So not only could they not adopt the pose physically because of the restrictions of their bones, even if they could adopt the pose, they wouldn’t have been able to stick their neck out of the water, as for example, these photographs of the Loch Ness monster or other sea monsters.

Karen: And speaking of supposed evidence for the Loch Ness monster, I was reading about the Dinsdale film on your website, which is supposed to be the best evidence, video evidence for the Loch Ness monster. Supposedly it shows a creature that moves with a paddling action, so would this be in keeping with the known locomotion of the plesiosaur?

Dr. Smith: Not at all, no. Because, originally, again, this is quite interesting because there’s lots of correlations between the descriptions of Loch Ness Monster sightings and what plesiosaurs were thought to look like or thought to behave like at the time. So in the 50’s and 60’s then these sorts of descriptions would have fit quite nicely, but today we know they’re not. So I find that quite an interesting correlation between the descriptions and the science at the time and in terms of the swimming, they didn’t row. Plesiosaurs were original thought to have rowed along using their limbs as paddles a lot like a Viking boat. So they’d have a strong powerful back stroke and then they’d feather their limbs to reduce the drag to move them forward and then push them back again. We know from looking at the construction of the joint where the humerus, the main arm bone, and the femur, the main leg bone, meet the girdles that they just couldn’t adopt this motion so they actually had a more up and down flying sort of motion so their limbs were actually developed into wings for underwater flight rather than paddles for paddling along. But one of the big questions was not how they move their individual limbs, which we actually are quite confident about this flying motion. The big question is how did they move four limbs relative to each other, because no animal today has four limbs which they use for locomotion, propulsive locomotion. So a plesiosaur is like the equivalent of a penguin with an extra pair of wings on the back and there’s nothing around like that today.

Blake: You mean aquatic wings, right?

Dr. Smith: Aquatic, yeah. Of course.

Blake: I saw a horse… [laughs]

Dr. Smith: [chuckles] Yeah. So, for moving around, you could say that a turtle has four pair of legs for swimming, but it actually only uses its front limbs for swimming…

Blake: Wow, okay.

Dr. Smith: …so the hind limbs are just used for steering. And the plesiosaur you could say were made the same, but if you look at the limbs in the front and the back, sometimes the hind limbs are even larger than the forelimbs. And both are very similar shaped, this wing-like shape, so they’re clearly both used for propulsion. But the question is how did they move relative to each other. So did they all four of them move up and down together or did they all move forward and backward together or did they alternate so that when the front limbs were moving down, the front limbs were moving up? So there are all these different hypotheses, which we’re at the moment trying to work out which is the most likely. But what we do know is that they weren’t rowing.

Blake: That’s really neat. How are they doing that? Are they using, I mean, can they see where the muscles connected and hypothesize how things were configured in that way? Is that how it’s being…?

Dr. Smith: Exactly, yeah yeah. There are particular processes on the limbs and there’s also muscle scars so you can reconstruct the musculature of the limbs and of the girdles and you can try and get an idea of how they moved. The problem is, this is how we know that they used this modified form of flying where they moved their limbs up and down rather than forward and back. But the difficulty is trying to determine how each of the limbs moved relative to each other and there’s a lot of speculation in that. Experiments have been done putting two people in a pool, for example, and attaching them to each other and seeing what works best. Not particularly scientific, but it’s a lot of fun to watch. And then people have tried to create robotic plesiosaurs which are thrown into a pool, and they’ve tried to program them to see if moving all four limbs together works best or if moving them alternatively works best so there’s a research effort at the moment to try and determine exactly how they did move.

Blake: I can’t think of any reptiles that don’t have a land-based portion of their life, even if they’re aquatic most of the time, but the massive frames of the plesiosaurs, you’re saying, seems to imply that they probably didn’t lurch up on the beach.

Dr. Smith: Not just their frames. It’s also the fact that their limbs are so well developed for an aquatic lifestyle so they don’t have a very strong articulation of the limb girdles to the vertebral column. So if they were to find themselves washed up on, say, a beach, if they were to try and move along, all of that force on the down stroke, one of these powerful down strokes, would not be transferred to the body. So underwater this is fine because all of that force is transferred to the water and moves the body along, but if you want to move, then unless that force is transferred to your body then you can’t move forward. You also have the huge problem of a massive and very large organism. Maybe small plesiosaurs with their small mass might have been able to circumvent that problem and may have been able to move along in small hops, but that would be pure speculation. And as we’ve talked about with the probable ability to give birth to live young, there would be no real reason for them to come out onto the land because they didn’t need to lay eggs or anything.

Blake: Right, and I think I wasn’t thinking in that way but I am now.

[laughter]

Blake: I need to think of them more like dolphins.

Dr. Smith: Exactly. I mean, plesiosaurs weren’t the only group of marine reptiles. You have other marine reptiles like the icthyosaurs which are very dolphin-like and we know 100% that there was no way that these guys could move around on land, and so this is just one example of a group of marine reptiles which were 100% restricted to the marine realm.

Blake: They’ve always reminded me of turtles. Right? It’s just a little bit…

Dr. Smith: Yeah.

Blake: …in their body shape. But they have such a long neck. What do we think the evolutionary advantage of such a long neck is?

Dr. Smith: It’s quite interesting. When the first plesiosaurs were described they were described as looking like a snake threaded through the body of a turtle, so your comparison to a turtle is apt. The function of a long neck is another one of these really difficult questions to answer similar to the four limb problem. We just don’t know what animals with four limbs do because there’s none around today to compare them to. Similarly there’s no marine organisms, marine tetrapods, animals with four limbs which also have a long neck. There’s no marine animals like whales or fish or dolphins that have a long neck. There’s no other animals around today that we can compare them to so the question of what they were doing is a difficult one to answer. Obviously they were doing something well because they lived throughout the Mesozoic era. So this is 180 million year duration so they were not failures at all; they were very successful. So their long neck which actually increased in length throughout their evolution was certainly doing something very important but we just really aren’t too sure what. The main hypothesis at the moment is that the long neck was used almost as a disguise so that it would be able to, the head, the small head, would be able to penetrate into a school of fish for example without the school of fish realizing that on the other end of this extremely long neck was a giant predatory marine reptile and before the fish would know what had happened they would have been snapped up in a go. But it’s just not really possible to tell exactly what these long necks were used for. Also the neck is a very vulnerable part of the body so it doesn’t seem like a very sensible thing to do to have this very vulnerable part of your body exposed in such a way when you have organisms like mosasaurs which are large predatory animals, or the large plesiosaurs with the short necks living around you in the same waters so to put your neck on display like that seems like quite a foolish thing to do from an evolutionary perspective, but obviously it worked, whatever they were doing.

Karen: And plesiosaurs were air breathers, weren’t they? So they would have needed to remain close to the surface most of the time.

Dr. Smith: Yeah, exactly. They, just like all reptiles, they had lungs and they breathed air so they would have surfaced several times a day like turtles would. Actually this is another good example, going back to the Loch Ness Monster idea of why it’s very unlikely that a plesiosaur is the Loch Ness Monster if Loch Ness Monster indeed exists, because plesiosaurs being air breathers would have to surface frequently. Maybe every hour or so and if this was the case then you would be having sightings constantly and we just aren’t.

Blake: Right. It’s a question that always gets asked I think when we talk about this with biologists. What kind of a breeding population would you expect to have to have to keep a population like this alive?

Dr. Smith: Yeah, it’s difficult. Obviously you can’t have just one or two animals living in the loch. It just wouldn’t work. It wouldn’t be a viable population. We’re talking maybe 100 individuals or so, bare minimum. So actually quite a lot when you’re talking about a single loch. And these are potentially animals that are 15 metres long. But again, because they are extinct organisms, it’s very difficult to say; to answer these sorts of questions with any amount of certainty.

Karen: So as you say, how likely is it that populations of plesiosaurs are extinct today, say on a 1 to 10 scale being completely ridiculous to scientifically likely?

Dr. Smith: You’d have to look of course at the evidence and the evidence is nothing. So if your scale is 0 to 10 and your evidence is 0, you’d have to say 0, that it’s very very unlikely. That doesn’t mean they don’t exist. You can’t prove a negative, of course. But there’s absolutely no scientific evidence whatsoever.

Blake: When did plesiosaurs disappear from the fossil record?

Dr. Smith: They were part of the KT extinction event which is the same extinction that killed off the dinosaurs and many other groups of marine reptiles, the pterosaurs and the ammonites, these squid-like invertebrates. So they were part of the mass extinction 65 million years ago at the end of the cretaceous period. So between 65 million years ago and today in lochs of that age you don’t find any plesiosaur fossils whatsoever. So again this is a good indication that it’s very unlikely that these animals are around today.

Blake: Do we have a record of their predecessors in the fossil record? Do we know how they evolved?

Dr. Smith: Yes we do. There’s a group of organisms called nothosaurs, which are superficially plesiosaur-like in their general morphology except their limbs are not quite developed into flippers. They’re still more like webbed feet and so these guys can walk around on the land. And if you back further still, more basal toward the bottom of their family tree you have even smaller animals called pachypleurosaurs and these are 30 centimeter long lizard-like organisms. You might be forgiven for mistaking them for a baby plesiosaur, for example. But all of these animals, although superficially looking like a plesiosaur, strictly speaking aren’t plesiosaurs and they’re actually a lot older. These are from the Triassic period, whereas all plesiosaurs are from the late Jurassic and cretaceous periods. Their actual position within the reptilian, within the reptile family tree is still uncertain but we have a good idea of where they are; at least what their closest relatives are.

Blake: Very cool. This is all really neat.

Dr. Smith: They’re awesome animals. I’m sorry some of the answers are so ambiguous. That’s the state of the science at the moment and like I say, on one hand it’s frustrating, but on the other hand it makes them all the more interesting because you can speculate and be forgiven. Your science can only take you so far.

Blake: Well, I think one of the factors that we look at especially on our show is that we think science is really about solving mysteries.

Dr. Smith: Mmm-hmm.

Blake: You’ve got lots of real mysteries here, but you’ve also got a lot of reasons why we think it’s safe to say, okay there’s not a plesiosaur living in Loch Ness. I think we would be seeing their bodies; we would be seeing the live ones come up; we would be seeing the mating. There are lots of reasons.

Dr. Smith: And also, you’d expect to see a lot more sightings today as well.

Blake: That’s right. More people watching would….

Dr. Smith: More people looking. More people with cameras on their phones. More cameras everywhere. So if there was a real phenomenon here, if there was a real plesiosaur living in Loch Ness, you’d expect the number of sightings to go up, you’d expect the number of photographs to go up and actually the reverse is happening and you’re finding less and less and less.

Blake: Exactly.

Dr. Smith: So I think this is a very clear trend and I think it’s quite obvious what that means.

Blake: And at the same time there are plenty of mysteries that science is tackling and these are really good examples, you know.

Dr. Smith: Yeah. It’s actually quite frustrating as a plesiosaur researcher. You can’t have a plesiosaur news story, if there’s a new species of plesiosaur described in the press or some new discovery on their anatomy or their biology, it’s impossible for that story to go ahead without some mention of the Loch Ness Monster in there and it’s actually quite frustrating because there are so many more interesting aspects to plesiosaurs without the references to the Loch Ness Monsters and the sea monsters.

Karen: Yeah, you said on your website as well that you interviewed by someone recently and they asked you up front if the Loch Ness Monster was a plesiosaur or a cousin of the plesiosaur and that…

Dr. Smith: Yeah, exactly, yeah. Presuming that there is a Loch Ness Monster in the first place. It was quite surprising. That’s exactly what prompted me to write the article on living plesiosaurs on my website in the first place. I was quite surprised that people actually presumed that there is something there at all, let alone whether it was a plesiosaur or something else.

Blake: Have you looked at coelacanth swimming? You just reminded me of that. Don’t they have four fins or…?

Dr. Smith: They may have four fins. The difference between the coelacanths and the plesiosaurs is that plesiosaurs didn’t have a tail for locomotion as well. So the plesiosaurs…

Blake: Good point. Good point.

Dr. Smith: The plesiosaurs were purely using their limbs to move around whereas most of the aquatic organisms use a tail, so the whales and the dolphins and the fish and even the other marine reptiles such as the icthyosaurs and the mosasaurs, they were all using their tails for locomotion. Actually even the ancestors of the plesiosaurs, the nothosaurs I mentioned earlier, the pachypleurosaurs, their mode of locomotion was also using this snake-like undulating motion with the whole of their body to move through the water. Somewhere along the line enter the evolution of plesiosaurs and their locomotion changed from this axial locomotion emanating from the spine to this paraxial locomotion emanating from the limbs, so it’s interesting why this happened. Again, this is another aspect of their paleobiology and evolution which we’re only really just starting to understand but it’s actually a really interesting aspect of it because moving with your limbs in the water is quite an odd way to go about moving underwater. It makes much more sense to use your tail.

Blake: If your tail’s not become a little bitty nub like these.

Dr. Smith: Yeah. I have found some evidence in one or two plesiosaurs where there may be just a kink in the tail, maybe some compression from side to side which I’ve actually interpreted as evidence for some sort of expanse at the distal part of the tail, at the very tip of the tail, some sort of rudimentary fin, however I’m not suggesting that they were using this for propulsion, but really just for shifting locomotion or maneuverability or stability or some other function.

Blake: Is there a relationship between the length of the neck and the length of the tail?

Dr. Smith: No, there’s isn’t actually. The tail is actually quite stunted. The plesiosaur morphology generally is actually quite standard. All of them have quite a short tail; all of them have a long barrel-like body; all of them have four wing-like flippers; all of the variation, the majority of the variation seems to be in the length of the neck and the size of the head.

Karen: To refer back to the toys that you’ve got on your website. The way that they’re portrayed is very different in each particular example.

Dr. Smith: Yeah. Yeah, it’s interesting as well. This also changes with time as well. So you have a nice correlation with the science and with the form of the toys. One of the most frustrating aspects of the toys of plesiosaurs in particular is that the heads of plesiosaurs are more often then not appallingly inaccurate. The main problem I’ve found is that the eye sockets, the orbits, are usually positioned way too far back in the forestry, in the openings in the back of the skull. So, in dinosaurs this is the case, you have orbits that are positions quite far back, but in plesiosaurs the orbits are actually positioned halfway along the skull quite near the front of the skull. So I think what’s happening is that the sculptors are taking the first plesiosaur reconstruction that they find on a Google search and are using that as a basis for their toy and not realizing that this is actually based on a dinosaur. So that’s quite frustrating to see these sort of inaccuracies propping up again and again and again in pieces of toys. It just niggles at me.

Blake: You’ve got me all interested in this whole ‘why do they have long necks’ question now. So who’s working on that question now or are they just waiting for a breakthrough?

Dr. Smith: Um, well there are several people working on it. There’s a researcher called Lesley Noé who has done some research into the posture of the neck and his research concluded that in contrast to the old reconstructions where the necks were lifted upwards, he concluded that the necks primarily could move downwards and could shoot straight down toward the seabed. His hypothesis was that the necks were used almost like a vacuum cleaner to suck up stuff around on the seabed and that they were eating crustaceans and organisms living in the sediment. It’s just another hypothesis to add to the list.

Blake: It would help if you could tell how fast they move, wouldn’t it?

Dr. Smith: A few studies have tried to look at the speed of plesiosaurs but again, they vary quite significantly based on the shape and size of their head and neck. Having a long neck on the front of your body when you’re trying to be a streamlined organism is quite an unusual feature to have and this is probably why, we were talking about the stiffness of the long neck earlier and trying to maintain a streamline shape is probably why they have this very stiff neck. If you have a wibbly wobbly neck you have all sorts of problems trying to move around at fast speeds, if you hold out your neck straight out in front like the prow of a ship you can move through the water a lot quicker, a lot smoother. It’s easy to make an argument why no animal should have a long neck like plesiosaur. It’s more difficult to say why they should.

Blake: Yeah, when you’re actually given the evidence you got to go with, ‘okay!’ [laughs]

Dr. Smith: Yeah, it’s very difficult. Like I say, the most likely hypothesis is that they were using their neck to sneak up on prey rather than using it proactively like a fishing rod or anything like this. I think that they were sneaking into a school of fish and then snapping one…

Blake: The default I always think about is food, food food. But there’s always sex.

Dr. Smith: Of course, there are a few hypotheses for sauropod dinosaurs. Sauropod dinosaurs are these animals with the very long neck. Of course long neck in a terrestrial animal you can compare directly to an extant animal like a giraffe and you can say, of course the long neck is being used to reach leaves high up on the trees. But there have actually been some hypothesis for sexual selection in sauropod necks and I’ve wondered if maybe the long plesiosaur neck has been selected because of sexual pressures, a little bit like the tail of a peacock. You look at the tail of a peacock, its function isn’t really obviously apparent. It doesn’t make any sense for catching food or being stronger. It only makes sense for being sexy. So perhaps the long neck increased in length to be considered a sexier adaptation. Who knows? It’s speculation.

Blake: It’s speculation. That’s precisely the example I was thinking about. I’m trying to picture these animals having intercourse and it’s not working out.

[laughter]

Dr. Smith: I’ve never actually thought about it.

Blake: Don’t sharks kind of go belly to belly?

Dr. Smith: Yeah, I presume plesiosaurs must have done a similar thing. This is how dolphins achieve this as well so, yeah. I guess so.

Blake: That’s weird looking in my mind. I need to stop…

[laughter]

Dr. Smith: Their necks weren’t particularly flexible, but maybe they entwined a little. Who knows?

Blake: That’s so romantic!

[laughter]

Blake: They’re necking.

Dr. Smith: It might be worth mentioning one unusual habit that they have. The majority of plesiosaur skeletons, the long necked ones anyway, are often found with fossil stones in their stomach regions.

Blake: Oh really!

Dr. Smith: Yeah! These are called gastroliths, or stomach stones and they’re actually found in many animals today. You can find them in birds. Birds eat grit. You can find them in crocodiles and several other organisms as well. So there’s this unusual habit in plesiosaurs, actually going back to their ability to live in fresh water, the environments in which the plesiosaur lived were actually very silty sediments, so the fact that they are often found with stones in their stomach which are very different from the sediment in which they’re preserved indicates that they are going very close to shore, maybe along beaches, maybe they were swimming up rivers, to proactively seek out these stones to swallow them. The function of the stones is another one of these big mysteries in plesiosaur research. Were they used for ballast, to keep them positioned correctly in the water column? We mentioned that they were air-breathers and so this might be a method for keeping them down. A lot like the ballast that a diver would have. Maybe they were used for grinding up food in the stomach. Or maybe they were used for something different altogether.

Blake: So we don’t know if they had a gizzard?

Dr. Smith: We don’t know if they had a gizzard, no. No. But we do know they were eating stones. So quite an unusual habit. And some of the very long necked elasmosaurids, the elasmosaurids were the plesiosaurids with very long necks. As many as 72 vertebrae in an individual neck which is the largest number of vertebrae in any living vertebrate organism and extinct organism as far as I’m aware, and these have been found with as many as 300 gastroliths in their stomach region and these gastroliths are each, you know, pretty sizable. You could hold them in the palm of your hand; they’d be quite the weight. They were serving some kind of interesting function but we’re not quite sure what though.

Blake: So you’re saying that the number of vertebra in each of these variations is actually changing within the same order.

Dr. Smith: Within the same order, year. There are lots of different types of plesiosaur species and each of those different species has a different number of vertebrae. They also have a different form and morphology of vertebra as well. So some of them are elongate and the long-necked forms, for example are elongate. And the short-necked forms are quite squat and short.

Blake: That’s quite interesting.

Dr. Smith: Yeah. And also the evolution of the long neck in plesiosaurs arose from two main evolutionary processes. Firstly was this one that I mentioned that elongation of the individual cervical vertebrae. So each vertebra in the neck, each bone in the neck was stretched out so this provided additional length to the neck. The second method was the addition of individual vertebrae. So not only do you have an increase in the individual length of the vertebra, you have an increase in the number of the vertebrae. So this is the main mechanism in which they were increasing the length of the neck. It’s also possible that they increased the length of the neck by shifting the pectoral girdle. The pectoral girdle is the bones which support the forelimbs, so the arms. So it’s possible that the pectoral girdle shifted backwards along the vertebral column increasing the length of the neck and shortening the length of the backbone but this is quite a new aspect for research. So there are all these interesting mechanism for the evolution of the long neck.

Blake: Seriously! That seems like there must be a tremendous pressure to have a really long neck.

Dr. Smith: Yeah, there was something going on. We just don’t know what.

Blake: How long a period of time are we talking about for these kinds of variations to appear?

Dr. Smith: Well, even the very first plesiosaurs have a really long neck and some of their ancestors, the nothosaurs and the pachypleurosaurs they have a reasonably long neck as well so it could simply be that the long neck is just their ancestral form which has just been retained and whatever function it was serving once it was present was expanded upon later on in their evolution. The very first plesiosaurs in the earliest Jurassic have a long neck and then in the latest mass [unclear word], the very end of the Cretaceous, just before the extinction of the plesiosaurs, their necks are even longer. But on the other side of things, you also have this pliosaur line of plesiosaurs. These are the short-necked plesiosaurs. So simultaneously you have this other group of plesiosaurs which are developing a shorter and shorter and shorter neck. So the earliest plesiosaurs have a sort of intermediate sized neck with maybe 30 vertebrae or so. Then one lineage shoots off and has a huge increase in the number of vertebrae which increases the length of the neck. Then on the other side of the order you have this short necked family which are decreasing the size of the neck. Some of the plesiosaurs in the pliosaur superfamily have as few as 13 vertebrae in the neck so there’s this huge dichotomy in the group in terms of their morphology.

Blake: That is so interesting. [laughs] I think because, I’ll always think of the selective pressures and how these sorts of mutations and other variations can radically change the morphology of an animal over time and this just seems like a really great example of how these changes can take place within a single line.

Dr. Smith: What really interests me is the lack of this long neck in any other marine organism. That’s the most intriguing aspect of the mystery to me because you would think that if this long neck had such a huge advantage that you would expect to see it at least in one or two species of fish for example or maybe in some long necked whales or dolphins and you just don’t see it. So of course you have evolutionary constraints within these groups, but the rarity of the long neck combined with its huge success within the plesiosauria, it’s a huge mystery.

Blake: That’s true. It seems like an indication it’s probably more like a sexual pressure than like a food one. Because the same animals would be competing for the same food sources. So…

Dr. Smith: Yeah.

Blake: I don’t know. But, you know, it’s just my opinion. [laughs] and I am not a scientist! But it’s neat though. Very interesting. Thank you for coming on and answering so many questions about plesiosaurs.

Dr. Smith: My pleasure.

Karen: Thank you, Adam.

[Outro]

Blake: Thanks for listening to another episode of MonsterTalk. Today we heard from Dr. Adam Stewart Smith from the National Museum of Ireland. You can learn more about plesiosaurs and Dr. Smith’s work at his website: plesiosauria.com. MonsterTalk is the podcast companion to monstertalk.org and its sister site, monsterscience.org which collects articles and critically examples monster claims. Theme music, as always, was provided by Peach Stealing Monkeys.

[Outtake clip]

Blake: I don’t even know if he goes back and listens.

Karen: Actually, he probably doesn’t listen in. It’s something he’s done and that’s in the past and he’s moving on.

Blake: And it’s not available on audiocassette.



[laughter]

The views expressed on this program are not necessarily the views of the Skeptics Society or Skeptic magazine.