10 Hearty Facts About Thescelosaurus

Thescelosaurus means “wonderful lizard”—and by the end of this article, you'll know why.

1. The First-Known Specimen was Stuffed into Shipping Crates and Forgotten About for Over 20 Years.

During the summer of 1891, a small skeleton belonging to this then-unidentified plant-eating dinosaur was found in Wyoming. The remains were carefully boxed up and arrived at what’s now called the Smithsonian Museum of Natural History—where they languished, unopened, until 1913! 

2. T. rex and Triceratops Were Among Its Neighbors.

Thescelosaurus often gets sidelined in books and museums. This likely has something to do with the fact that, 66 million years ago, it shared Western North America with several infinitely more popular creatures like Tyrannosaurus, Triceratops, Ankylosaurus, and Pachycephalosaurus. Tough break.

3. Thescelosaurus Had a Robust Build.

With surprisingly thick ribs and limb bones, this cow-sized dinosaur was sturdily-constructed. Such stout, muscular body types have their advantages—Thescelosaurus might have used its heft to overpower small tyrannosaurs and other predators.

4. …And It Wasn’t Especially Fast.

Since its discovery, Thescelosaurus has been compared to vaguely similar-looking dinosaurs such as Hypsilophodon of Europe. However, unlike that critter, Thescelosaurus clearly lacked an affinity for speed. First of all, its femur (thigh bone) is similar in size to its tibia (shinbone). But in hardcore runners like Hypsilophodon, the latter bone is significantly longer. Also, Thescelosaurus’ toe bones were—unhelpfully—on the short and stubby side.

Obviously, Thescelosaurus was no marathon contender. That doesn’t mean it couldn’t be evasive: When necessary, a low center of gravity enabled this animal to make sharp, maneuverable turns.

5. Thescelosaurus Possessed Strong Arms, but Wimpy Fingers.

Given its broad shoulder blades and bulky arm bones, you’d think that Thescelosaurus was doing something strenuous with those forelimbs. So why did they come with small fingers and dinky claws? And while we’re on the subject, could Thescelosaurus walk around on all fours? Some paleontologists think it did so often, while others find a permanently-bipedal stance more likely. 

6. Thescelosaurus Probably Preferred Waterside Property.

A 2010 study proposed that, given the types of rocks their fossils are normally found in, Thescelosaurus usually lived around streams and rivers while “horned” dinosaurs (eg: Triceratops) targeted drier real estate. To each their own…

7. Its Skin May Have Had Hard Lumps of Armor.

Ryan Somma, Flickr

Isolated blobs of armor plating have been found in close proximity to a few Thescelosaurus skeletons. But some argue that these didn’t necessarily belong to the actual dinos; the corpses in question likely came to rest in bodies of water and, at some point, it’s possible that bony plates called “scutes” popped off of some nearby crocodilian cadavers and drifted over post mortem.

8. A New Species was Recently Announced.

In 2011, Thescelosaurus assinoboiensis was named. According to paleontologist Tim Tokaryk, “there are features in the cranium, the back end of the skull, and a few features in the pelvis” which separate T. assinoboiensis from the other known Thescelosaurus species (T. neglectus and T. garbanii).

9. “Willo”—A Very Famous Thescelosaurus Specimen—Contains “Cell-Like” Structures.

Taking a Tar Heel State road trip anytime soon? Be sure to swing by the North Carolina Museum of Natural Sciences. On the third floor, you’ll get to meet “Willo,” a dinosaurian celebrity. First uncovered in 1993, Willo is the most complete Thescelosaurus skeleton ever found, and looks plenty compelling to the naked eye. But things get even more interesting at the microscopic level: What’s been described as “cell-like” material has been spotted on “his” bones. Did this stuff actually belong to Willo himself? We can’t ascertain its origin just yet; it could have belonged to a plant he happened to have died around.

10. Also, Many Scientists Once Thought That Willo Had a Fossilized Heart.

Ryan Somma, Wikimedia Commons

Back in 2000, the world freaked out when a strange-looking lump inside his chest was interpreted as the preserved remains of a genuine dinosaur heart. Better still, it seemed like this so-called circulatory organ was of the powerful, four-chambered variety, much like ours.

Unfortunately, since then, this idea has been flatlined: A 2011 re-analysis concluded that Willo’s new claim to fame was really nothing more than a rocky concretion. Still, even without this heart of stone, Willo—like every Thescelosaurus—remains a “wonderful lizard” indeed. (Of course, dinosaurs weren’t actually lizards—they were much more akin to crocodilians. But that’s a topic for another day…)  

Prehistoric Ticks Once Drank Dinosaur Blood, Fossil Evidence Shows

Ticks plagued the dinosaurs, too, as evidenced by a 99-million-year old parasite preserved inside a hunk of ancient amber. Entomologists who examined the Cretaceous period fossil noticed that the tiny arachnid was latched to a dinosaur feather—the first evidence that the bloodsuckers dined on dinos, according to The New York Times. These findings were recently published in the journal Nature Communications.

Ticks are one of the most common blood-feeding parasites. But experts didn’t know what they ate in prehistoric times, as parasites and their hosts are rarely found together in the fossil record. Scientists assumed they chowed down on early amphibians, reptiles, and mammals, according to NPR. They didn’t have hard evidence until study co-author David Grimaldi, an entomologist at the American Museum of History, and his colleagues spotted the tick while perusing a private collection of Myanmar amber.

A 99-million-year-old tick encased in amber, grasping a dinosaur feather.
Cornupalpatum burmanicum hard tick entangled in a feather. a Photograph of the Burmese amber piece (Bu JZC-F18) showing a semicomplete pennaceous feather. Scale bar, 5 mm. b Detail of the nymphal tick in dorsal view and barbs (inset in a). Scale bar, 1 mm. c Detail of the tick’s capitulum (mouthparts), showing palpi and hypostome with teeth (arrow). Scale bar, 0.1 mm. d Detail of a barb. Scale bar, 0.2 mm. e Drawing of the tick in dorsal view indicating the point of entanglement. Scale bar, 0.2 mm. f Detached barbule pennulum showing hooklets on one of its sides (arrow in a indicates its location but in the opposite side of the amber piece). Scale bar, 0.2 mm
Peñalver et al., Nature Communications

The tick is a nymph, meaning it was in the second stage of its short three-stage life cycle when it died. The dinosaur it fed on was a “nanoraptor,” or a tiny dino that was roughly the size of a hummingbird, Grimaldi told The Times. These creatures lived in tree nests, and sometimes met a sticky end after tumbling from their perches into hunks of gooey resin. But just because the nanoraptor lived in a nest didn’t mean it was a bird: Molecular dating pinpointed the specimen as being at least 25 million years older than modern-day avians.

In addition to ticks, dinosaurs likely also had to deal with another nest pest: skin beetles. Grimaldi’s team located several additional preserved ticks, and two were covered in the insect’s fine hairs. Skin beetles—which are still around today—are scavengers that live in aerial bird homes and consume molted feathers.

“These findings shed light on early tick evolution and ecology, and provide insights into the parasitic relationship between ticks and ancient relatives of birds, which persists today for modern birds,” researchers concluded in a news release.

[h/t The New York Times]

The Clever Adaptations That Helped Some Animals Become Gigantic

Imagine a world in which eagle-sized dragonflies buzzed through the air and millipedes as long as kayaks scuttled across Earth. "Ick"-factor aside for bug haters, these creatures aren't the product of a Michael Crichton fever dream. In fact, they actually existed around 300 million years ago, as MinuteEarth host Kate Yoshida explains.

How did the prehistoric ancestors of today’s itty-bitty insects get so huge? Oxygen, and lots of it. Bugs "breathe by sponging up air through their exoskeletons, and the available oxygen can only diffuse so far before getting used up," Yoshida explains. And when an atmospheric spike in the colorless gas occurred, this allowed the critters' bodies to expand to unprecedented dimensions and weights.

But that's just one of the clever adaptations that allowed some creatures to grow enormous. Learn more about these adaptations—including the ingenious evolutionary development that helped the biggest dinosaurs to haul their cumbersome bodies around, and the pair of features that boosted blue whales to triple their size, becoming the largest animals ever on Earth—by watching MinuteEarth's video below.


More from mental floss studios