In our 98th episode, we had the pleasure of talking with Dr. Victoria Arbour, a NSERC Postdoctoral Fellow on the Royal Ontario Museum/College of Toronto, Canada and an ankylosaur skilled. You’ll be able to observe her on twitter @VictoriaArbour
Episode 98 can be about Homalocephale (Prenocephale), a pachycephalosaurid that lived within the late Cretaceous in what’s now Mongolia.
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On this episode, we talk about:
- The dinosaur of the day: Homalocephale (Prenocephale)
- Homalocephale identify means “even head”
- A pachycephalosaurid that lived within the late Cretaceous in what’s now Mongolia
- Described in 1974 by Osmólska & Maryañska
- Just one species, kind species is Homalocephale calathocercos
- Could also be a synonym (and juvenile kind) of Prenocephale
- Kind species is an incomplete cranium and postcranial materials. Had giant openings on the highest of the cranium and a big, spherical eye socket. Scientists described it as an grownup, although it has juvenile traits (like a flat cranium). Then in 2010 Nick Longrich and others mentioned it might simply be a juvenile model of one other grownup pachycephalosaur (Horner and Goodwin additionally steered that in 2009). Longrich steered it was a juvenile or sub-adult of Prenocephale
- Herbivore, about 6 ft (1.8 m) lengthy
- Had a flat, wedge-shaped cranium roof, although the cranium was fairly thick (that is much like Dracorex and Goyocephale, and never much like different grownup pachcephalosaurs)
- Had a broad pelvis (some paleontologists assume it might have had vast hips to provide dwell delivery, others assume the vast hips helped defend organs throughout flank-butting)
- Had lengthy legs and was quick
- Had a really inflexible tail
- Can see Homalocephale within the recreation Jurassic Park: Operation Genesis (you construct your personal Jurassic Park)
- Maryanska and Osmolska described Prenocephale in 1974
- Title means “sloped head”
- Lived in Mongolia within the late Cretaceous
- Fossils discovered embrace skulls and fragmentary publish cranial stays
- Three species: Prenocephale prenes, Prenocephale brevis, Prenocephale edmontonensis
- Kind species is Prenocephae prenes
- One other steered synonym to Prenocephale is Sphaerotholus buchholtzae
- Herbivore, about 7.8 ft (2.4 m) lengthy, weighing 280 lb (130 kg)
- Prenocephale had a spherical, sloping head, with a row of smally bony spikes and bumps
- Thought to have a stout physique with a brief neck, brief forelimbs, and lengthy legs (primarily based on different pachycephalosaurs, since all that’s been discovered is generally skulls
- Some scientists assume Prenocephale might have been an omnivore (ate vegetation and bugs), although many assume it ate leaves and fruit
- In all probability a selective browser, because it had a narrower snout than different pachycephalosaurs
- Pachycephalosaurs might have head butted or they could have used their domes to draw mates
- Teenage or younger grownup pachycephalosaurs have been greatest outfitted to deal with head butting (skulls had radiating constructions that compressed, offered cushion throughout a battle)
- Adults don’t have these constructions
- Widespread Practical Correlates of Head-Strike Conduct within the Pachycephalosaur Stegoceras validum (Ornithischia, Dinosauria) and Combative Artiodactyls revealed in PLOS ONE June 2011, by Eric Snively and Jessica M. Theodor
- Snively and Theodor in contrast Stegoceras and Prenocephale skulls with head-butting mammals (like elk and musk ox) with CT scans. They discovered Stegoceras and Prenocephale domes have been most much like musk ox and duiker
- Stegoceras was most in a position to head butt
- Distributions of Cranial Pathologies Present Proof for Head-Butting in Dome-Headed Dinosaurs (Pachycephalosauridae) revealed in PLOS ONE July 2013, by Joesph E. Peterson, Collin Dischler, Nicholas R. Longrich
- Peterson and his workforce studied 109 domes from 14 species to see if there was proof of head butting. 22% of these domes confirmed proof of osteomyelitis, which regularly comes from cranium trauma. As a result of there was plenty of proof of this, they concluded it was in line with the thought of intraspecies fight
- In addition they checked out 30 skeletons of head-butting mammals and located that “Comparisons with accidents in extant bovids illustrate the variation in damage and lesion distribution associated to conduct and recommend that the distribution of accidents in extinct animals can subsequently be equally used to deduce conduct in extinct taxa”
- Pachycephalosauria is a clade of ornithischians
- Title means thick headed lizards
- Lived within the late Cretaceous in North America and Asia
- Bipedal with thick skulls
- Enjoyable reality:
This episode was dropped at you by:
The Royal Tyrrell Museum. The Royal Tyrrell Museum is situated in southern Alberta, Canada. One of many high paleontological analysis institutes on the earth, your entire museum is devoted to the science of paleontology. It’s undoubtedly a should see for each dinosaur fanatic. Extra info will be discovered at tyrrellmuseum.com.
For many who might favor studying, see beneath for the total transcript of our interview with Dr. Victoria Arbour:
Garret: Victoria Arbour is a Postdoctoral Fellow on the Royal Ontario Museum/College of Toronto in Canada, and he or she is likely one of the world’s main consultants on ankylosaurs, which is why I actually wished to speak to her. So personally my favourite dinosaur is Ankylosaurus. Is that your favourite dinosaur too, or do you want a special ankylosaur higher?
Dr. Victoria Arbour: Oh it’s exhausting to determine as a result of I like plenty of them rather a lot, however Ankylosaurus is certainly cool, it’s undoubtedly one in every of my favourite of the ankylosaurs. Yeah, I’d be exhausting pressed to select a really favourite one which I can love rather a lot like cool issues, there are a complete bunch of various ones.
Garret: Very cool, yeah your bio on the College of Alberta says that you just’ve recognized 4 new species of ankylosaurs earlier than you bought your PhD, is that true, that appears too unbelievable to be?
Dr. Victoria Arbour: Oh effectively it’s type of true though possibly I must replace a few of these issues. So one of many initiatives that I labored on whereas I used to be a PhD pupil on the College of Alberta, was having a look on the variety of ankylosaurs in Alberta particularly by kind of broadly in North America and Mongolia. And one of many ankylosaurs that’s the most effective recognized ankylosaurs is named Euoplocephalus. It may not be a very easy identify to say however most ankylosaurs toys are literally Euoplocephalus not Ankylosaurus. So it’s like a extremely widespread one to see reconstructed, however they typically simply name it Ankylosaurus although they’re completely different animals. However I can’t actually blame them, as a result of it’s not a very easy identify to say.
This is likely one of the dinosaurs that—or one of many ankylosaurs that now we have essentially the most specimens for, but it surely additionally has like a extremely lengthy stratigraphically. So it has like a very long time vary that it was present in, and the extra that we find out about Alberta dinosaurs specifically, the extra that we all know that they have an inclination to have comparatively restricted stratigraphically. So we discover them generally simply in a single a part of the geologic formation, and never fairly often do we discover them in multiple geologic formation inside Alberta, in order that’s fairly cool.
So I took a take a look at whether or not or not all these completely different specimens that we have been calling Euoplocephalus truly have been all one specie, as a result of there have been some variation and I wished to know whether or not or not that was identical to regular variation, to see whether or not the species, or whether or not or not if it actually had development or sexual dimorphism, and even simply squishing throughout fertilization.
So among the work that I did truly kind of, I didn’t identify these species, however I resurrected previous species that had been bumped in with Euoplocephalus. There truly had been a few completely different species in Alberta, and again within the Nineteen Seventies one other actually widespread Ankylosaurus researcher Walter Coombs determined that in all probability all of these represented one species. However now with this new framework of dinosaur species, which is in Alberta, I used to be capable of finding that we had truly 4 completely different species had been lumped in with Euoplocephalus.
That was actually enjoyable, so we had an animal referred to as Dilophosaurus which is represented by a reasonably good skeleton on the Royal Ontario Museum, and it has a extremely skinny tail membership and a [inaudible 00:03:09] which is present in youthful segments than a lot of the Euoplocephalus specimen which might be present in that present park. It has a extremely cool pointed ax-like tail membership. And Scholosaurus, which is understood from a extremely nice skeleton that’s on show on the British Museum of Pure Historical past that has pores and skin impressions and all of it, osteoderms, and [inaudible 00:03:29] which is admittedly cool.
It’s additionally recognized from specimens from Montana. So it’s one of many few that crosses the Alberta mark gender board. So yeah—so I didn’t get to call these new ones as a result of they’re fairly exhausting names, however I did get to point out that they really have been distinct. And that we truly had a a lot higher variety of ankylosaurs, and that not the entire variations that we noticed in Alberta was identical to intra-specific variation that actually was completely different. That was a extremely enjoyable undertaking to work on.
Garret: Yeah that sounds actually cool. So when you’re doing that type of analysis the place did you give you the previous species names? Had been they—all these ones—these particular ones had been beforehand recognized with completely different species names, after which lumped again collectively underneath the identical species?
Dr. Victoria Arbour: Yeah.
Dr. Victoria Arbour: Yeah, it’s a comic story; we don’t actually speak about kind of synonyms and resurrecting all issues, as a result of it’s simpler to speak about new names, like figuring out a brand new species. However that’s when plenty of Alberta dinosaurs have been being named; it kind of was like each new specimen obtained a brand new identify. After which as individuals discovered an increasing number of specimens, they might take a look at issues and be like, oh I’m probably not positive that these are all that completely different. There may be plenty of variation; we are able to’t have like 30 completely different species of ankylosaurs in like 2 million years in Alberta.
However possibly all of those are actually only one, however like I mentioned now that we kind of obtained like a brand new framework for the way we consider these species and the way we perceive their distribution in Alberta, now we have a significantly better sense of—however there’s type of completely different like cohorts of dinosaurs, specifics kind of teams that get discovered collectively on the identical time. After which they type of shift and get a brand new group of dinosaurs, which is fairly cool.
Garret: Received you, so it’s a bit little bit of splitting after a complete bunch of lumping?
Dr. Victoria Arbour: Yeah, and I’ve thought actually it’s actually enjoyable. I actually like doing it, I like determining what species now we have. However it’s all the time altering too as a result of new specimens result in new info that make you take a look at issues in a brand new mild. So I believe it’s one in every of these items that’s all the time a bit bit in flux although you type of need it to remain steady as a lot as doable.
Garret: Yeah, and I believe at that stage the place you’re looking at whether or not they’re completely different species is a bit bit simpler than the entire like ought to they be in the identical genus or not. I’ve been studying a bunch about that, and that’s such a large number making an attempt to outline what a genus is.
Dr. Victoria Arbour: Yeah, it’s actually tough. So what I did in my undertaking was I checked out all of the previous style. All of the previous genus issues as a result of I didn’t wish to make one thing actually sophisticated referred to as a brand new mixture, the place you want take a brand new genus identify and take an previous species identify and put them collectively, they usually kind of like a complete like hybrid identify out of all the things. And the definition if you recognize what a genus is, is a bit bit versatile and particularly completely different taxonomies engaged on my very completely different teams.
We’ll have kind of completely different ideas of what makes a genus versus a species. So in the event you work on beetles your thought of the quantity of variations that you just use to name one thing a special genus relatively than completely different species is sort of completely different from what dinosaurs actually focus to. However that’s okay; all people kind of understands that there’s a little little bit of flexibility in there and that it’s probably not a tough and set rule. So the principle factor is that we attempt to be constant inside our personal teams, and simply type of acknowledge the work that we’re all doing collectively.
Garret: Good, so so far as when you’re saying an ankylosaur, that’s truly a stage up from a genus proper, is that like…
Dr. Victoria Arbour: Yeah, it’s truly a few ranges up from a genus relying on what number of ranges do you want to acknowledge. So one of many issues—so ankylosaurs are a fairly large group of dinosaurs. They don’t seem to be like the largest group, they don’t seem to be as fairly as various as say just like the [inaudible 00:07:13], the issues that embrace like [inaudible 00:07:16] dinosaurs and the bottom [inaudible 00:07:17] and every kind of fascinating creatures like that, however they’re fairly various they usually type of have two principal teams.
There may be one group that’s referred to as the nodosaur ankylosaurs, and that by no means entails a tail membership that type of pull like ax construction on the top of their tail, however they typically have like actually large shoulder spikes. They preserve this kind of a protracted snout that actually ankylosaurs had, and they’re fairly cool animals in their very own proper as effectively. The opposite principal group of the ankylosaurs are – these are those I spend most of my time with, and that’s the group that ultimately evolves a tail membership.
They have a tendency to have kind of a squash, like a squash snout, a extra kind of daring lengthy type of face; they don’t have so long as [inaudible 00:08:00] has. In order that’s kind of like the 2 principal teams, and a lot of the ones that I’ve labored on are in that tail membership group.
Garret: Cool, so talking of tail membership evolution, I learn your paper on the tail evolution and it’s one in every of my favourite papers. And also you speak about how they went from a versatile tail in early ankylosaurs, they usually obtained a stiff tail a bit bit later with some fused vertebrate or vertebrae. And then you definitely had the membership ultimately forming with osteoderms on the finish of the tail.
So I used to be type of curious once I was studying this, what’s the—simply how helpful having simply the stiff tail with out the osteoderms on it will be? Wouldn’t it be type of like having a bat or one thing on a tail or…?
Dr. Victoria Arbour: Yeah, that’s how I prefer to image it. To me that’s one of the fascinating questions is that we’ve seen within the picture truly to have this sample such as you mentioned the place the tail turns into stiff effectively earlier than they get like a extremely giant a part of bone on the tip of the tail. They’ve osteoderms that go down the tail, however they in all probability like peferred [ph] all the best way right down to the tip. After which solely a lot later do they get that kind of big like huge ball of osteoderm on the tip.
So I type of image having simply the deal with, kind of the deal with of the axe, the deal with of the tail membership is a bit like having a baseball bat on the top of the tail. So possibly it’s not fairly as efficient a weapon as having that full axe head on it, but when somebody is chasing you round with an axe or chasing you round with a baseball bat, you’re going to in all probability run away from each of these issues, even when like a baseball bat can’t like chop your leg off or one thing.
I assume that will be too grave [inaudible 00:09:39] I don’t need somebody to love smash a baseball bat, so yeah so I believe it may have functioned like that. I haven’t accomplished any bionic chemical research of what an ankylosaur tail with no kind of no bone on the finish, how it will operate. However I believe that’s a extremely cool space that we may take a look at in future and attempt to perceive kind of just like the operate in biomechanics of kind of these hack tail golf equipment.
Garret: Yeah, since you did write a paper in regards to the biomechanics of a tail with the membership proper? And also you confirmed that…
Dr. Victoria Arbour: That’s proper.
Garret: What was the conclusion you had there; I neglect precisely what you realized?
Dr. Victoria Arbour: So what I used to be making an attempt to cross in, I’ve a kind of a pair of papers, one the place I do some mathematical modeling to see how briskly it happens an ankylosaur completes its tail. After which I took that info and used finite component evaluation, which is sort of a particular engineering method the place you possibly can apply power to a digital mannequin of no matter you need, and see what occurs to it while you say smash it or one thing.
And so what I wished to know was whether or not or not ankylosaur is particularly may even like construct their tail membership with any vital quantity of power. After which extra importantly whether or not or not they may stand up to that estimated power and not using a break. As a result of if they will swing it actually quick and exhausting however then it breaks as quickly because it touches one thing, in all probability they might not have used their tail golf equipment in that approach, as a result of that looks like poor design.
So yeah so the factor that I did was I additionally modeled kind of a spread of assumptions. It’s actually powerful in some methods to view among the biomechanical evaluation, as a result of we don’t have just like the muscle of the mushy tissues that actually affect how animals transfer particularly in a tail the place there’s plenty of completely different bones and plenty of muscle that assist transfer the tail in many alternative instructions.
So I used a spread of various assumptions like how a lot muscle there would have been on the tail, completely different kind of charges of muscle tissue contractions, completely different like plenty of bone and issues like that. And we even have completely different sizes of tail golf equipment. So some tail golf equipment are fairly small, possibly solely like 15 or 20 centimeters vast, however then some are actually, actually huge. The largest one I believe I’ve ever measured is about 61 centimeters vast.
Dr. Victoria Arbour: Which is admittedly large particularly when you think about like the quantity represented by that, wow. They’re actually heavy and I’m not completely even positive like how an animal eats one thing that heavy up off the bottom when it’s so far-off from its physique. I believe it has rather a lot to do possibly with the tendons that they’ve kind of ossified tendons that run alongside the tail. I’m getting off monitor right here, so the query—so the factor that I wished to know was whether or not or not they might break underneath these estimated forces that I did.
And the brief reply might be not. The longer reply is it’s actually exhausting to inform generally. So underneath a few of my mannequin assumptions the actually large tail golf equipment would break underneath like the best incurred forces. However underneath the kind of extra conservative estimates that I did about affect, pace and mass and all of these enjoyable issues, they in all probability may stand up to it. Their tail golf equipment have been fairly good at dissipating the thrust by the knob and thru the deal with of the tail membership. And possibly solely the very largest one which they hit them actually exhausting would truly break their very own tails.
Garret: So how briskly did you assume that they might be swinging these tails? Was it identical to as quick as you’d want to interrupt one thing or have been nearly …
Dr. Victoria Arbour: I believe it will actually rely. I believe that for among the actually large ankylosaurids with actually large tail membership nodes, I believe that that in all probability would have been like sufficient of a visible sign to opponents to not even strategy. In the identical approach that like for instance plenty of like closely armored animals at the moment like porcupines, like plenty of animals gained’t even strategy these. They’re simply not prey and they don’t seem to be greater ear with greater [inaudible 00:13:40] type of intimidate smaller ear with smaller [inaudible 00:13:42], they usually don’t even have like—as a result of they’ve obtained a sign there, a visible sign that claims I’m going to win.
So I believe that among the ones with the actually big tails in all probability didn’t truly even use them a complete lot if we type of take into consideration them like trendy animals. After which for a few of these, the kind of like extra affordable measurement one, say those in kind of 40 cm vary. I’d should look, I all the time neglect precisely what the affect velocity, and affect power precisely is. However it’s rather a lot; it’s sufficient to interrupt bone undoubtedly. If an ankylosaur tail membership smashed into like a [inaudible 00:14:22] ankle or possibly one other ankylosaur’s ribs, it undoubtedly would have cracked that bone. That’s a lot power behind them.
Garret: Yeah, that’s measuring keep on with have, if it’s sturdy sufficient to interrupt bone you may not even go close to it.
Dr. Victoria Arbour: Proper, yeah particularly like skinny bones like ribs and like ankle bones, I believe it will have been fairly weak.
Garret: Yeah, I believe that’s truly why I like ankylosaurs the perfect, as a result of it’s type of like a type of pacifist animals. My spouse and co-host Sabrina loves sauropods, I believe for a similar cause the place it’s like, effectively it’s so large all the things simply leaves it alone.
Dr. Victoria Arbour: Yeah, so I believe that’s very true. I believe specifically plenty of ankylosaurs have been in all probability utilizing their tail golf equipment largely towards one another actually. Once we see like weapons in most trendy animals, weapons are actually for combating members of your personal species. A variety of weaponry evolves by kind of male to male fight, and curiously typically when it is advisable defend a useful resource, in order that appears to be the driving kind of selective stress in trendy animals that evolve weapons. It’s nearly all the time males beginning some kind of useful resource associated to copy.
So there’s actually cool analysis on the market particularly on beetles, sacred beetles, rhinoceros beetles, the place the males are defending [inaudible 00:15:49] and kind of utilizing their weapons to shove different animals, like different members of that species away, in order that they will mate with the females in that world. In order that appears to be the principle cause that weapons evolve, however definitely weapons can be utilized to guard your self from the predators as effectively. However that’s in all probability probably not like for driving selective stress behind plenty of weapons.
And so I suspected it’s in all probability one thing comparable with ankylosaurs and it’s one thing that I’m hoping to research in a bit extra element as I preserve doing my analysis. So plenty of what I’ve been doing recently is how weapons evolve in ankylosaurs and different dinosaurs and different extinct animals like glyptodonts. In order that’s been plenty of enjoyable as effectively, but it surely’s tough to see a few of these issues out in extinct animals.
Garret: Yeah, glyptodonts, these are these like big armadillos with a spiky kind tail membership factor?
Dr. Victoria Arbour: Yeah, that’s precisely proper. One of many papers that I’m engaged on proper now could be having a look at what kind of correlations are there related to having a tail membership. So what do ankylosaurs and glyptodonts have in widespread that may assist us perceive why they advanced these actually weird tails. The tail weapons are actually uncommon. Not very many animals ever actually use their tails in fight particularly in trendy animals, and there aren’t actually any trendy animals which have a specialised weapon and not using a tail. So one thing like a tail membership or say like a spike on [inaudible 00:17:19] tail.
So it’s actually solely in a few issues and they’re all extinct. In order that makes it a kind of enjoyable problem to strive to determine like what’s driving like tail weapon evolution, and what kind of led to this very comparable structuring to completely unrelated teams of animals, due to course such as you mentioned glyptodonts are—they’re simply large armadillos. They’re simply actually large eared armadillos. Eared armadillos that like have rigid tail items and brief skulls, and they’re herbivores, however they’re simply big armadillos. And so they evolve these actually bizarre tails which might be much like ankylosaur tails although they kind of do their tail golf equipment in a barely completely different approach. It’s nonetheless a extremely comparable construction in completely completely different teams of animals.
Garret: Yeah, do you’ve gotten any opinions on why extra animals don’t have these tail protection mechanisms?
Dr. Victoria Arbour: Yeah, so that is nonetheless analysis that’s type of in progress, so it’d change a bit bit as I end it up. However among the issues that appear to be kind of statistically vital for having a tail membership that actually correlated with it and should be there first with a view to have a tail membership are issues like being actually large and armored. In order that’s in all probability not shocking, however these issues appear to be in place first earlier than tail weaponry can evolve. And at the moment we don’t actually have any large armored animals.
Dr. Victoria Arbour: There are armored animals on the market are like armadillos and turtles, however none of them actually get this kind of really gigantic sizes. And in order that is likely to be like a significant cause that we don’t have tail golf equipment, or different tail weaponry round at the moment, as a result of we simply don’t have like large armored animals in any respect.
Garret: Fascinating, are there extra ankylosaurids or are ankylosaurids typically greater than nodosaurids?
Dr. Victoria Arbour: No truly if I’ve to essentially guess and I must double-check this. However I believe that nodosaurs truly are sometimes a bit large greater than ankylosaurs.
Garret: Oh fascinating.
Dr. Victoria Arbour: However they’re all actually large, so good, it’s kind of like splitting hairs a bit bit there I assume. So the very largest ankylosaur ever I’m fairly positive is Ankylosaurus out of all ankylosaurs. It’s a extremely large animal, it simply has an enormous head, and it in all probability had an enormous physique as effectively though we don’t have any skeletons of it. However among the nodosaurs that we discover within the lake group options like [Adventomania] are additionally actually large animals. And I believe they’re in all probability not less than a bit bit greater than the ankylosaurs that lived on the identical time. Issues like Euoplocephalus. Yeah so if I needed to guess I’d say that nodosaurs may need edged out most ankylosaurs besides Ankylosaurus.
Garret: Okay, that’s fascinating. Is there—you talked about a bit bit in regards to the conserving the tail off the bottom. I’ve seen that recreations of ankylosaurs or no matter you recognize articulations have been presenting the tail like slowly, larger and better off the bottom.
Dr. Victoria Arbour: My favourite illustrations of ankylosaurs are when ankylosaurids are proven with their tail like a scorpion place.
Garret: How good.
Dr. Victoria Arbour: Like over their physique, like whooping, like a tyrannosaur on the face or one thing. I’ve some actually—I’ve a extremely, actually humorous assortment of photographs of ankylosaurs combating. Different animals had actually bizarre ways in which don’t actually make any sense. However yeah, so I’m unsure in the event that they get larger. I believe ankylosaurs are actually fascinating as a result of yeah, just like the tail is admittedly heavy, and it’s heavy far-off out of your physique, but when you consider—in the event you ever do like weights or something and also you strive like holding photographs, effectively I determine that is simply me, but when I simply maintain like a 15 pound weight like away from my physique like out from the aspect, I normally can’t do it for very lengthy.
Garret: I don’t assume very lengthy.
Dr. Victoria Arbour: Okay that’s good, so it’s actually exhausting. I provide you with like one and I’m like, “Oh God I’m drained,” [inaudible 00:21:21]. So yeah, so it takes much more like muscular power for us to carry a heavy weight like additional away from our physique. And it type of makes you marvel if it’s the identical factor in an ankylosaur tail, as a result of these tail [inaudible 00:21:33] are actually heavy and their tails are fairly lengthy, not so long as like a [inaudible 00:21:38] tail, however they don’t have like—even actually straight [inaudible 00:21:40] have type of brief tails, and ankylosaurs nonetheless have like proportionately lengthy tails.
So one factor that I believe is likely to be serving to a bit bit with them not having to make use of like muscular energy to maintain the tail off the bottom is that this actually intricate sequence of ossified tendons that run alongside the tail membership. So ossified tendons are tendons like now we have in our our bodies, however they change into ossified like [inaudible 00:22:06]. So instance of one thing like that’s in turkeys. That is nice as a result of in Canada, we’re having Thanksgiving subsequent weekend. In turkeys, in the event you ever ordered like a hen, while you eat the kind of drumstick piece, and there’s all the time that like actually skinny, like toothpick bone in there.
A part of that’s an ossified tendon, so, and I believe it’s all—Oh no sorry, that’s a part of the—that’s the fibula actually scale back, however there are ossified tendons in [inaudible 00:22:31] and plenty of fowl legs truly. So yeah so ossified tendons is one thing that we discover in plenty of dinosaurs, particularly plenty of herbivorous dinosaurs, however normally they’re extra kind of like over the again, and over the entrance of the tail. And in ankylosaurs all approach down on the tip of the tail, and working alongside that steep a part of the tail, the tail a part of the tendon.
So I believe that what’s in all probability taking place is the ankylosaurs makes use of kind of like muscle tissue to maintain the tail within the entrance above the bottom, however then it’s in all probability relying not less than a bit bit on these ossified tendons to maintain the tail from dragging like actually closely on the bottom, and possibly additionally utilizing it a bit bit by way of swinging the tail back and forth, as a result of the ossified tendons kind of retailer elastic power as effectively. And that’s one thing that’s a bit bit more durable to mannequin when you’re doing mathematical mannequin of the tail bone. Sure, so I believe the ossified tendons in all probability play a reasonably key function, though it’s a bit more durable to really like take a look at that and examine it in a significant approach.
Garret: Yeah, it makes plenty of sense. I figured there needed to be some type of inside construction. I’ve a background in engineering, so like I’ve all the time checked out issues and imagining the stresses and forces concerned, and yeah.
Dr. Victoria Arbour: Proper, it’s like doing this type of work then, it’s actually enjoyable.
Garret: Yeah, it’s fascinating.
Dr. Victoria Arbour: Yeah, so it’s a—I’m additionally not completely against the thought of ankylosaurs possibly having their tail membership touching the bottom generally. We don’t have any proof for that, though there are ankylosaur [inaudible 00:24:00] there’s in all probability largely nodosaurs or not less than ankylosaurs with out tail golf equipment, they usually don’t drag their tails. You don’t see tail drag marks in nodosaurs monitor leads.
So it’s a little bit up within the air whether or not or not ankylosaurs may have accomplished that, however I don’t assume it’s too loopy that they battle about issues like rested them on the bottom generally. Once more as a result of they’re like fairly heavy, and particularly in the event that they get greater and larger, they may droop a bit additional.
Garret: Yeah fascinating, simply out of curiosity, why do you assume extra animals or dinosaurs don’t have osteoderms or some type of armor?
Dr. Victoria Arbour: That’s query. So osteoderms are bone, and bone is admittedly costly to take care of in your physique. Osteoderms are like particular bones that kind within the kind of decrease stage of the pores and skin, they’re just like the dermal layer, in order that’s the place osteo means bone and dermis the pores and skin, they’re merely pores and skin bones. People don’t actually have something like that, however it isn’t unusual in different animals, so it’s the identical factor that varieties the shell of armadillos, turtles have osteoderms typically instances of their legs and arms, however their shell will not be osteoderms, it’s truly their ribs.
Crocodiles have osteoderms and a few lizards like gila monsters, and gila monsters have osteoderms as effectively, however [inaudible 00:25:25]. So it’s one thing that we see kind of in plenty of completely different teams, however not in each member of these completely different teams, as a result of once more like most mammals do not need like osteoderms. So it in all probability has to do with the commerce offs in kind of sustaining plenty of additional bone in your physique, and the entire like minerals, and like sources that it will take to each develop these and preserve them maintained.
So it’s kind of a commerce off between the fee it’s a must to put into it, and the profit that it does for you by way of say like not being human, or no matter different operate that osteoderms have. So osteoderms have a few completely different features that we all know of in trendy animals. They do supply safety towards predation basically when you’re very small. It is smart, however there’s precise proof behind that for like sure lizards, just like the thicker and extra osteoderms you’ve gotten, the much less doubtless you’re to [inaudible 00:26:19].
Dr. Victoria Arbour: In crocodiles they appear to even have a thermoregulatory operate, in order that they appear to have a little bit of a operate in each like absorbing and dissipating warmth which may be very fascinating, as a result of they’ve blood vessels in them, in order that is smart. After which a paper that was revealed lately additionally exhibits that they act as calcium storage websites. So when crocodiles are on the point of lay eggs, they pull calcium out of their osteoderms earlier than they pull it out of different bones of their physique. To allow them to additionally appear to behave a bit bit as like calcium reservoirs for animals that lay eggs.
So osteoderms in all probability have plenty of completely different functions, and in sure dinosaurs, they in all probability additionally served as once more visible diploids, so it’s exhausting to argue that the plates of a stegosaurs that are osteoderms don’t have any type of like visible signaling system or operate, as a result of they’re so large and like flamboyant. They certainly should have some kind of like – that’s actually, that’s in all probability what these are for.
And even some ankylosaurs are comparable, so some ankylosaurs have very like flamboyant [inaudible 00:27:24] osteoderms like big spikes on the entrance of the shoulder. They’re like giant, large, triangular plates alongside the edges of the hips. So these in all probability have a bit little bit of a defensive operate, a bit little bit of a thermoregulatory operate, possibly they’re additionally working as calcium reserves, however they may even be visible indicators as effectively. In order that they in all probability have plenty of completely different features, after which it’s simply kind of a matter of just like the commerce offs of anyone or all of these features mixed versus once more the power after [inaudible 00:27:54] maintained.
Garret: Okay, yeah that is smart. That type of jogs my memory there’s this paper, I believe it was this 12 months that talked about these giant pits that ankylosaurs would get of their osteoderms, did you occur to see that?
Dr. Victoria Arbour: I’m unsure I’ve seen that one, however ankylosaur osteoderms do typically have like actually bizarre texture, they’re actually like bubbly and nobly. A few of them appear to have pathologies in them. However yeah a few of them generally get these actually large [pepsederm 00:28:24], and I believe that it’s actually fascinating, however I haven’t learn the paper with that but.
Garret: Okay, I used to be questioning if possibly that was a part of it like there’s a threat for an infection that comes with osteoderms, or one thing that will make it in order that not all animals wished them.
Dr. Victoria Arbour: I don’t know, I imply osteoderms are nonetheless lined so their bones will not be like uncovered in any respect. In order that they nonetheless would have been lined by like a scale, like a kind of like a attractive like virgin scale in life. Not very many animals have identical to straight up like uncovered bone. I believe one basic instance is armors, however armors are actually big. So, yeah like they might have been lined by some kind of like attractive masking. So I don’t assume they’d be liable to an infection like greater than different components of the physique except in fact possibly they’re more durable to heal in the event that they get bitten or broken or one thing like that, however that I’m unsure about.
Garret: Yeah, I believe within the paper there have been some explicit micro organism or one thing that they have been guessing may need gotten into it by like both a chunk or another mechanism, after which it unfold or one thing like that.
Dr. Victoria Arbour: Fascinating.
Garret: It’s fascinating. Yeah it was in, I simply discovered it. It was within the Journal of Paleopathology.
Dr. Victoria Arbour: Oh that sounds enjoyable.
Garret: Yeah, I believe it’s the one article I’ve ever learn from that journal, however I must test it out extra typically. So, on a lighter observe, getting away from paleopathology, I do know that you just helped out the group making the sport Saurian on their digital ankylosaurs mannequin?
Dr. Victoria Arbour: Yeah.
Garret: Are there any options that you just type of inspired them to incorporate or that you’re significantly enthusiastic about which might be of their model?
Dr. Victoria Arbour: I’m actually enthusiastic about Ankylosaurus as a result of I believe that collectively we got here up with like the perfect, most correct reconstruction of it that’s on the market at the moment. It was very nice working with them as a result of the primary draft they despatched me, I had plenty of feedback about it, they have been completely actually—and like not as a result of that they had accomplished a foul job, simply it’s exhausting as a result of there’s not plenty of info on the market and realizing Ankylosaurus is such a family identify. There isn’t plenty of info on the market. There may be a few papers, however they’re like skeletons and [inaudible 00:30:38] to go together with that.
So I had plenty of feedback, they usually have been actually nice about simply working with it, and we kind of completely retold it like gave it a complete new kind of osteoderm association, like new interpretations. So I’m actually excited as a result of I believe it simply seems to be nice. I believe it seems to be like an actual animal, not like some type of merged collectively monstrosity that Ankylosaurus generally appear like as a result of they’re exhausting to interpret, they usually don’t actually appear like something round at the moment. So it’s type of exhausting to love — they don’t seem to be like intuitive animals to reconstruct, and osteoderms are plenty of work for artists to work on.
Yeah, so I’m actually enthusiastic about that, after which it additionally was voted one of many new playable characters. After they launch the kind of first launch of the sport, it’s going to be the subsequent one which turns into one of many kind of characters you possibly can play from a child as much as an grownup. I’m actually excited to be working with them on kind of instructing what I find out about Ankylosaurus [inaudible 00:31:36] and development basically, and making use of that to make kind of like a cool story for Ankylosaurus, so I’m actually wanting ahead to it.
Garret: Yeah me too, I voted for Ankylosaurus with our kick begin of votes.
Dr. Victoria Arbour: Oh good, I did too, however I’m in all probability a bit biased. Yeah, so I believe it’s going to be actually enjoyable, and I believe—I’m truly not somebody who performs all of the video video games as a result of I are likely to get like very movement sick from plenty of like, particularly like 3D video video games, however I’ve been actually excited to work on this and kind of do this new medium of scientific storytelling, as a result of it’s a bit bit completely different than say like a tv documentary and even like a college course, as a result of the gamers get to make selections about what they’re doing as these dinosaur characters.
I believe it’s a extremely neat approach to get individuals kind of extra immersed within the science behind dinosaur analysis as it’s at the moment. And it’s identical to a cool medium to be serving to out with, so I’m wanting ahead to it.
Garret: Positively, it’s too dangerous that you just say you get movement sick, as a result of they’re going to make a VR model too.
Dr. Victoria Arbour: I undoubtedly won’t be able to play that one I do know, however I’m wanting ahead to making an attempt this one out then. I’d simply should do it a bit bit, however I believe it’s going to be actually good. I believe it’s going to be plenty of enjoyable.
Garret: Yeah, I like the colours that they selected too, or did you’ve gotten any affect on the orange and brown theme that they type of put?
Dr. Victoria Arbour: Yeah, a bit bit. In order that they got here up with a few completely different like various choices after which requested for my suggestions on them, and yeah I like going with kind of a brightly coloured ankylosaur. I kind of just like the excessive kind of distinction that prefer it’s kind of darkish, however then it obtained issues like brilliant patches on the remainder of the physique. So I believe that appears fairly cool.
I wished to maneuver us away from like brown ankylosaur. As a result of they don’t essentially should be like neon colours, however I believe they’re actual animals, and you recognize animals have completely different sorts of colour patterns in some options, and atmosphere every kind of issues. So yeah why not have a pleasant colourful ankylosaur.
Garret: Yeah, and particularly while you talked about the porcupine analogy. If animals are simply going to keep away from it as a result of they acknowledge it as one thing you possibly can’t actually mess with, it makes good sense for it to be brightly coloured, as a result of then you definitely get the assembly show to associate with it.
Dr. Victoria Arbour: Proper, and yeah plenty of animals use like warning coloration or not less than warning patterns, kind of brilliant contrasting patterns to kind of point out hazard. We don’t actually have any proof for this in ankylosaurs, however I believe it appears fairly believable and affordable, yeah and nicer than simply having kind of like an everyday like simply brown ankylosaur, individuals consider so.
Garret: Yeah, or inexperienced like plenty of sample depictions.
Dr. Victoria Arbour: Proper, yeah after which I’m positive some have been inexperienced, and that’s nice, however plenty of ankylosaur artwork doesn’t kind of painting ankylosaurs in very like favorable mild. They typically do like simply type of standing there not wanting significantly sensible or falling off cliffs is a factor that’s simply taking place additionally in ankylosaur artwork. I’ve like a number of examples of Ankylosaurus identical to falling off of hills. And I’m like, “Oh man, they’re not that,” I imply they’re in all probability not like tremendous sensible animals, however they in all probability may keep away from falling off the cliffs like some would have thought.
Garret: Yeah they’ve a low middle of mass; they’d be good at like not falling.
Dr. Victoria Arbour: Proper, yeah it’s identical to a humorous factor that retains exhibiting up. I don’t actually assume I’ve seen that with different dinosaurs fairly often. It’s identical to a bizarre, I don’t know, it’s only a bizarre factor, a bizarre factor about Ankylosaurus.
Garret: That’s bizarre, cool, so identical to a type of last research-y query, is there anything that you’re enthusiastic about, that you’re researching or wanting ahead to?
Dr. Victoria Arbour: I’ve actually cool issues on the go that I can’t actually completely speak about but, however I hope that any listeners will keep tuned for cool ankylosaur stuff within the subsequent couple of years. I simply began a brand new publish doc on the Royal Ontario Museum, I used to be fairly helpful on the North Carolina Museum of Pure Sciences making an attempt some actually cool issues, I’m ending up there actually big weapons analysis at how dinosaurs introduced weapons. And a few of my focus on the Royal Ontario Museum goes to be a bit extra of like patterns in dinosaur bio geography.
So Ankylosaurus, but additionally like teams of 5 ankylosaurs and kind of understanding like how sea stage, and local weather, and land bridges, and various things like that influenced how they dispersed between North America and Asia in the course of the [inaudible 00:36:13].
And I believe that’s going to be actually cool as a result of I believe we’re going to have the ability to be taught some actually fascinating issues about what kind of like environmental and organic components influenced broad scale migrations between [inaudible 00:36:25]. I believe that’s going to be actually […].
Garret: Does that tie into your analysis in regards to the Ankylosaurus swimming?
Dr. Victoria Arbour: Sure a bit bit. I hadn’t completely determined to take this path once I wrote that paper, however that paper kind of gave me the impetus to additional make investments a few of these issues. In that paper I had taken a take a look at a sample that had been famous by different affiliate […] earlier than that nodosaurid ankylosaurs appeared to wind up in marine settlements greater than ankylosaurid ankylosaurs.
I took one other take a look at that with among the new species that now we have recognized, the brand new specimens, and did some statistical evaluation and discovered that, yeah they do wind up in marine settlements extra typically than ankylosaurids, however not all over the place and never all the time. It’s largely in North America that we see that exact sample, and that’s in all probability as a result of North America retains getting flooded by the massive Western inside sea approach.
In order that seaway has a extremely large affect on ankylosaur variety in the course of the [inaudible 00:37:28] interval, as a result of not less than from the info that now we have proper now it looks like North America had it’s kind of personal like dwelling grown, like group of ankylosaurid ankylosaurs and nodosaurid ankylosaurs. However the ankylosaurs truly obtained extinct as the ocean stage will get actually, actually excessive, after which misplaced the species. And so a lot of the ankylosaurid is the one with tail golf equipment which might be actually well-known from North America like Ankylosaurus and Euoplocephalus are literally Asian immigrants that got here in a lot later and kind of re-colonized North America.
So it’s actually fascinating to see how issues like sea stage, and hopefully we are going to check out say like temperature or possibly even issues associated to my food regimen or physique mass would possibly kind of affect kind of like extinction occasions in several place or dispersal occasions in several place, and simply attempt to assist us perceive just like the sample of dinosaur evolution in North America, and possibly we are going to even be taught a bit bit about what’s in retailer of us as local weather adjustments and [fear of horizons 00:38:29] these days. So I believe it’s going to be a extremely cool undertaking.
Garret: Yeah that sounds actually fascinating. I’ve to maintain my eyes peeled.
Dr. Victoria Arbour: It’s going to be a short while although as a result of I simply began, however I’m excited.
Garret: Nice, effectively thanks a lot for speaking to me. If individuals wish to be taught extra about you or your analysis or observe you, ought to they go to Twitter or the place ought to they go?
Dr. Victoria Arbour: Yeah, I believe Twitter might be the perfect place, and my Twitter deal with is admittedly easy. It’s simply my identify, so @victoriaarbour.
Garret: Nice, yeah you publish plenty of issues. I believe I re-tweeted one thing you posted at the moment that I preferred rather a lot.
Dr. Victoria Arbour: Oh yay!
Garret: A part of your—what did you name—hole…
Dr. Victoria Arbour: Oh drooling.
Garret: Drooling that’s kind of about this.
Dr. Victoria Arbour: Sure that’s one thing that I’m doing, largely only for enjoyable, however plenty of them are winding up having dinosaur too [inaudible 00:39:20].
Garret: Yeah, and kudos on the good artwork work. I preferred your—all of them thus far truly.
Dr. Victoria Arbour: Thanks, that’s so good of you, thanks.