Skip to main content



Image modified from Wikipedia.
Original image by Tim Evanson
Dinosaurs! Like most children, I devoted a sizable portion of my brain activity between the ages of 6 (when Lost World: Jurassic Park came out) and 10 (when the light finally died from my eyes) to thinking about dinosaurs. For whatever reason, Ankylosaurus was not one of my favourites or even one of the dinosaurs I thought about a lot (probably because it was not prominently features in the Jurassic Park movies). How do I feel about them now? Let's find out.


Ankylosaurus was a heavily armuored, and heavily armed, motherfucker with plates on the back and sides, and a club-like tail. Their skulls were covered with small bones, and they had horns on both the top and bottom of the head because having only one pair of horns is for dorks. The knobs on their bodies, as well as their clubs, were made of bony protrusions called osteoderms, which, incidentally, are present on modern crocodilians. These are called osteoderms because they are bony growths on the skin ("osteo" = bone, "derm" = skin). In alligators, they are used for protection of the vital organs and heat regulation - their osteoderms are full of little blood vessels, allowing the animal to cool down quickly. Because Ankylosaurus had more and larger osteoderms than alligators, they were probably much better at regulating temperature.

In addition to being covered in cool bone armour, Ankylosaurus was also an absolute unit. No complete fossil of Ankylosaurus magniventris exists, but by comparing Ankylosaurus bones to the complete skeletons of related species, dino-scientists estimate it was around 8 meters (26 feet) long. Dino-scientists also considered the circumference of the leg bones and asked a computer how much weight they could reasonably support, and came up with 4.78 metric tonnes (over 10,000 pounds), which is ridiculously huge.

Points: 1/1


So Ankylosaurus had a big fuck off club at the end of its tail, made of big fuck off osteoderms. Ever since the first Ankylosaurus club was discovered in 1910, people assumed that it was used for beating the absolute tits off of other dinosaurs, like Tyrannosaurus rex. It wasn't until the 2000s that somebody (specifically, Victoria Arbour) did a science to find out if that was even possible. They found that yes, ankylosaurids with large clubs could probably do some serious fucking damage, likely enough to break bones. Only one club specifically belonging to Ankylosaurus has ever been found, and it's a lot smaller than the biggest ones examined in the analysis, so it's possible that it was used for ritualized self-defense (threat displays) as opposed to explicit self-defense (bashing the other guy's brains in).

Points: 0.5/1 for ambiguity


Ankylosaurus fossils have been found exclusively in what is now midwestern North America, from Alberta to Wyoming. At the time it was alive (around the end of the Cretaceous, right before the extinction event that turned dinosaurs into birds), North America was mostly boreal forest and home to a multitude of gigantic herbivore species. The handful of Ankylosaurus fossils that have been uncovered were from what were once the coasts of shallow seas, although that only means that's where they were most likely to fossilize. Anyway, the climate changed around 65 million years ago and everybody got fucked. Even though Ankylosaurus succumbed to climate catastrophe, I can't really fault them for it because the fuckening was so widespread.

Points: 1/1 I guess?


Dino-scientists determined that ankylosaurids were herbivores, because they had flat, non-threatening teeth. They also had funky beaks, possibly for eating fruit - but they also don't have any external nares (AKA nose holes) so they may have been specialized for digging up tasty roots. Either way, they would have had to eat a shitload of vegetables in order to sustain their tremendous mass. They were about the weight of a small elephant, so consider how much an elephant has to eat and it's probably comparable. However, unlike elephants, Ankylosaurus appeared to be solitary, so they probably didn't do as much damage to the landscape as elephants do.

Points: 1/1


A. magniventis was just one species in a broader group of heavily armoured dinosaurs, the ankylosaurids, many of which we know a lot more about because their fossils are more complete. Thus, a lot of what we think we know about Ankylosaurus actually comes from other ankylosaurid dinosaurs. However, there is some evidence to suggest that Ankylosaurus was kind of weird among its relatives. For example, it had a smaller club than other ankylosaurids so, like I said earlier, it probably used its club for ritualized threat displays rather than outright bone-breakin'. As well, it seems to have more feeding specializations, suggesting it had a narrower diet than other ankylosaurids.

Points: 0/1 for non-conformity

Life History

Almost everything we know about dinosaur life histories comes either from trace fossils (fossils of things other than bones, like footprints and nests - these are obviously sort of sketchy because it's a lot harder to tell what animal left the trace), or the way bone-fossils are arranged together - for example, social animal remains are often found in groups. Since there are hardly any Ankylosaurus fossils, we know approximately dick about what they got up to when they were alive. No adult ankylosaurid fossils have been found together, so we assume that they were solitary animals, but other than that? Total mystery.

Points: 0.5/1 mysteries are cool but also infuriating

Interaction with Humans

Like most other dinosaurs, Ankylosaurus had the good sense to go extinct several million years before humans were ever invented.

Points: 1/1

Final Score: 5/7
Though mysterious, Ankylosaurus magniventis is a lot cooler than I thought, and I regret not giving it the attention it deserves when I was a dino-obsessed kidlet


  • Arbour VM. 2009. Estimating impact forces of tail club strikes by ankylosaurid dinosaurs. PLoS One. 4(8): e6738. Open Access
  • Arbour VM, Mallon JC. 2017. Unusual cranial and postcranial anatomy in the archetypal ankylosaur Ankylosaurus magniventris. FACETS. 2: 764-794. Open Access
  • Chen IH, Yang W, Meyers MA. 2014. Alligator osteoderms: mechanical behaviour and hierarchical structure. Materials Science and Engineering: C. 35: 441-448
  • Koch CF, Hansen TA. 1999. Cretaceous period. Encylopedia Britannica. Last updated Oct 16 2018. Link
  • Seidel MR. 1979. The osetoderms of the American alligator and their functional significance. Herpetlogica. 34(4): 375-380


Popular posts from this blog

European Stag Beetle

 EUROPEAN STAG BEETLE ( Lucanus cervus ) Modified from wikipedia Original image by Simon A. Eugster Stag beetles are a whole group of insects with big fuck-off horns on their face. I'm gonna talk about the best-known species, Lucanus cervus , whose name means "Lucanian deer", and is sort of condescending to the literal deer that presumably live in Lucania. Appearance Stag beetles exhibit sexual dimorphism, which means the females look physically different from the males. Female stag beetles look pretty much like your average beetle - that is to say, pretty and shiny, but don't make you say "woah, what the hell is that thing???" The male stag beetle (pictured), on the other hand, looks absolutely ridiculous. Like, what do you have going on there, buddy? Pinchers? For pinching? Who are you going to pinch with those? What look like pinchers are actually grotesquely oversized mandibles - the part of the insect used for grabbing and breaking up food. They need re

Pointy-Nosed Blue Chimaera

POINTY-NOSED BLUE CHIMAERA ( Hydrolagus trolli ) Image modified from Wikipedia. Original image copyright Citron. Since it is Halloween month, I'm going to write about chimaeras, AKA "ghost sharks", so-called because they look really pale and creepy. There's not really anything else seasonally appropriate about them but whatever, ghost sharks. They're also sometimes called "ratfish", and individual species often have stupid common names like "rabbit fish" or "elephant fish". Nevermind that. Ghost sharks. OOOOOOoooOOOoooOOOOOO. Since one of the common names for "pointy-nosed blue chimaera" is apparently the much more frightening "abyssal ghostshark", that's what I'll be calling them for the rest of this review. Appearance Chimaeras are named after a monster in Greek mythology that was half lion, half goat, half dragon, and 150% badass. Apparently whoever named these things (Linnaeus, I guess?) thought they lo

Hawksbill Sea Turtle

  Image modified from wikipedia;  original image by Thierry Caro HAWKSBILL SEA TURTLE ( Eretmochelys imbricata ) Okay so this one is going to be a little bit biased because hot golly gee god damn do I enjoy turtles. Especially  sea turtles. I just really think they're neat. Anyway, I'm going to try really hard not to give them undeserved points here, unlike my other reviews, where points are awarded based on extremely stringent criteria. Appearance Adult hawksbill turtles are, on average, one meter long, and weigh about 80 kg (roughly 3 ft and 150 pounds in freedom units). This seems pretty big for a turtle, but when compared to an absolute monster like the leatherback sea turtle, which grows up to 3 meters long and weighs as much as my old Kia, you realize that hawksbill turtles are the dainty lads of the sea, surpassing only the Ripley sea turtle in size. They are a rare combination of beautiful and adorable. Like, they have doofy little flippers and faces like grandmas, but