10 Pebbly Facts About Scelidosaurus

Scelidosaurus’ appeal is two-fold. Back in the 19th century, its discovery helped us understand just how strange dinosaurs really were. And, to boot, the primitive critter offers some much-needed perspective on an underexplored chapter in dinosaurian evolution. So what’s not to like?

1. It Was an Early Forerunner of Heavily-Armed Herbivores like Stegosaurus and Ankylosaurus.

Wanna be a paleontologist? One of the toughest parts of the gig is untangling an extinct animal’s family tree. Scelidosaurus, which evolved around 190 million years ago, is clearly a primitive thyreophoran, or armored dinosaur. At some point, this group split into two major branches: the tank-like ankylosaurs and the spiky-tailed stegosaurs. Scientists differ on exactly where Scelidosaurus fits within the thyreophora tapestry; some claim it’s more closely aligned with the ankylosaur camp while others feel it preceded the divide and, hence, may be ancestral to both factions.

2. Scelidosaurus Was Named by the Same Dude who Coined the Word “Dinosaur.”

Sir Richard Owen (1804-1892) invented the latter term during the spring of 1842. A year after Scelidosaurusdiscovery in 1858, this gifted naturalist scientifically described the creature and, due to its well-preserved hindquarters, gave it a name that means “limb lizard.”

3. Its Scales Were Small and Bumpy.

Associated skin impressions reveal that Scelidosaurus’ hide (at least the bits which weren’t covered in armored plating) featured tiny, rounded scales which created a pebbly, Gila monster-esque texture. 

4. Thanks to Nine Dino-Loving Grandkids, You Can See a Terrific Scelidosaurus Cast in Utah.

London looks, Flickr

Scelidosaurus displays are an uncommon sight in North America, but in 2011, Virginius Dabney of St. George, Utah, helped bring a top quality skeletal cast to this picturesque little city. When the locally-based Dinosaur Discovery Site museum expressed an interest in obtaining this item, Dabney, at his grandchildren’s urging, donated almost all of the necessary dough. “Now the grandkids can see grandpa’s dinosaur,” he said.

5. We’ve Found Some Pleasantly Intact Scelidosaurus Armor.

Scutes (bony armor plates nestled in an animal’s skin) usually scatter during fossilization. Fortunately, however, one beautiful Scelidosaurus specimen opted to leave most of its scutes intact and in the same bodily places they occupied during life. Now that’s courtesy!

6. It’s Classified as a “Bird-Hipped” Dinosaur.

Such fan favorites as Triceratops, Stegosaurus, and Iguanodon are technically known as ornithischian—or “bird-hipped”—dinos due to (among other things) the superficially avian-like position of their pubic bones. Long-necked dinosaurs like Brachiosaurus and carnivorous species such as T. rex belong to the “lizard-hipped” saurischian order. Confusingly, actual birds also belong to this second bunch. Hey, titles can be deceiving...

7. Scelidosaurus Can Claim an Important Historical Distinction.

This British critter was the first dinosaur to be academically described on the basis of a well-preserved, articulated, and (mostly) complete skeleton. Prior to its discovery, the scientific community had little more than isolated bones and fragmented dino bits to work with.

8. The Animal Was a Jurassic Island Dweller.

During its day, higher sea levels converted much of Western Europe (including the UK) into a series of clustered islands.

9. Scelidosaurus Fossils Hail From a Very Narrow Geographic Range.

Thus far, they’ve exclusively turned up in the greater Charmouth/Lyme Regis area of Dorset, England. To explain this, some scientists posit that, like today’s komodo dragon, Scelidosaurus may have only inhabited a single island, which would have been somewhere near these present-day villages.

10. But It Was Briefly Thought to Have Also Inhabited Arizona.

In 1989, a handful of isolated scutes which had been found in this southwestern state were cited as Scelidosaurus remains. However, several paleontologists have since rejected the claim, pointing out that these plates don’t look sufficiently Scelidosaurus-like to warrant a precise identification.

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.


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