Zigong Dinosaurs World Science & Technology Co.,Ltd. makes, as you can probably guess from the name, animatronic dinosaurs. Which, for some reason, they attempt to sell via spam email marketing. We at BoingBoing have gotten spam like this before, from other manufacturers in the surprisingly robust Chinese animatronic dinosaur industry. What made this particular email stand out to me, though, was the above picture, of an animatronic Glyptodont covered in fur.
Now, I'd seen Glyptodonts before, but the reconstructions that I remember came across more as giant armadillos, as opposed to the huge beaver with a shell on its back that you see here. So I contacted Brian Switek, my favorite dinosaur blogger, to ask him which image of the Glyptodont is the correct one.
His response: They both are.
Glyptodonts — a family of creatures that includes the species Glyptodon — were, in fact, ancient relatives of today's armadillo. Many of them were the size of a Volkswagen Beetle. Like the armadillo, Glyptodonts were mammals. And some of the species really did have hair — including on their shells.
What's really interesting is that this isn't totally out of line with the appearance of some modern armadillos. There are several species of hairy armadillos wandering around the Earth right now. One of them is called the screaming hairy armadillo, in honor of the high-pitched squeals it makes if you try to mess with it. Its fur is sparse and tufty, sticking up from its shell and its legs. But another species — Argentina's pink fairy armadillo — really does look something like the animatronic Glyptodont — a pink shell attached to the back of a white, fuzzy rodent.
It's easy to forget the furry parts of Glyptodonts, though, because when we talk about them we tend to focus on their much-more-impressive armor. Besides the obvious shells, various species also sported bony patches on their exposed skin and some even had spiky clubs at the ends of their tails. All of that made an awful lot of sense for a herbivorous creature that had to live alongside saber-toothed cats.
Of course, those defensive adaptations didn't always work. Last year, Brian Switek wrote about a fossil specimen of the species Glyptotherium that had clearly been ripped apart by a big, hungry predator.
Stored within the American Museum of Natural History’s massive Frick Collection of fossil mammals is the busted-up skull of a juvenile Glyptotherium texanum designated F:AM 95737. Tiny fractures run over the entire skull – damage done after death but before fossilization – but most remarkable are two oblong holes sunk into the frontal bones. These holes were likely made by a large saber-toothed cat (though a jaguar is another possibility), and, as assessed by paleontologists David Gillette and Clayton Ray, the apparent ease with which the predator dispatched its victim suggests that this Glyptotherium was stuck. Rather than a sabercat jumping out from nowhere and biting the glyptodont on the head, they reasoned, “It seems more likely that this juvenile was stranded, perhaps in mud, or was otherwise debilitated, unable to avoid an approaching predator.”
The single, perforated skull represents a lucky catch for a saber-toothed hunter, as well as paleontologists. Traces of predation on glyptodonts are rarely found. Juveniles – in which the armor plating had not fully ossified – may have been more vulnerable than adult glyptodonts, but predation on these animals was probably more common than the small collection of damaged bones suggests. The recent discovery of additional armor accessories hints that some of these shelled mammals were in an arms race with the predators of their time.
Read a Smithsonian article describing various Glyptodont specimens, including several with hair follicles on their shells.
Arizona was home to several species of Glyptodonts. Check out this article from Arizona Geology magazine that describes them particularly well.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.