10 Handy Facts About Deinocheirus

Five years ago, there wasn’t much one could say about Deinocheirus—but thanks to some amazing new discoveries, we can finally start connecting the dots and exposing the secrets of this enigmatic creature.

1. For Over Four Decades, It Was a Cryptic Mystery Dino.

Our story begins at the height of the Cold War. While exploring Mongolia in 1965, a Soviet team stumbled upon two massive and sinister-looking fossilized arms. At eight feet long each (!), these clearly came from an animal of frightening proportions—a beast which was promptly given the name Deinocheirus, or “terrible hand.”

But, in retrospect, perhaps it should’ve been called “terrible tease,” because the rest of Deinocheirus’ skeleton was missing! For years, those awesome appendages (and their shoulder girdles) were like the tantalizing trailer of a movie that was never released. With bated breath, dino enthusiasts hoped that Deinocheirus’ elusive body would eventually emerge. Finally, decent specimens started popping up in the late 2000s and early 2010s.

2. Deinocheirus is the Largest-Known “Ostrich Dino.”

Ornithomimids, or “ostrich dinosaurs” (as they’re sometimes colloquially called), were a group of bipedal omnivores which roamed North America and Asia during the Cretaceous period (145.5 to 65.5 million years ago). By default, the most famous species is Gallimimus, an animal that regularly zips into Universal Pictures’ Jurassic Park series.

3. It Would have Led a Relatively Slow-Moving Lifestyle.

Gallimimus and other ornithomimids are usually imagined as reptilian speed demons, but the 35-foot-long Deinocheirus utterly dwarfs its kin. To support its plus-sized physique, the dinosaur’s pelvis and hind legs are unusually thick by ornithomimid standards, indicating that Deinocheirus was more adept at lumbering than sprinting. 

4. Deinocheirus Had a Fishy Diet.

Though its jaws and beak seem custom-made for handling veggies, plants weren’t Deinocheirus’ only option: some mashed-up fish remains (scales, bones, etc.) were found inside one specimen’s stomach.

5. It Had a Feathery Tuft at the Tip of its Tail.

Here’s a fun word: pygostyle, which, in Greek, means “rump pillar.” These are fused bony clumps on the ends of modern bird tails that are designed to support feathers. Interestingly, Deinocheirus had a small one, which was probably topped in a small, feathery fan. 

6. Surprisingly, Deinocheirus Had a Sail on Its Back.

It’s an accessory nobody saw coming! Though sail-backed dinosaurs are nothing new, no other ornithomimid is known to have sported anything even remotely akin to the huge, hump-like ornament that gave Deinocheirus its distinctive profile.

7. Its Forelimbs Belonged to a Class of Their Own.

Danny Cicchetti, Wikimedia Commons

Deinocheirus and the equally-bizarre Therizinosaurus (which would have shared its habitat) are noteworthy for having the longest arms of any bipedal dinosaur we’ve yet discovered.

8. Perhaps Deinocheirus Waded for Food Like an Oversized Waterfowl.

Did this off-beat dino frequent waterways? It’s been hypothesized that Deinocheirus’ wide, blunt toe claws would have helped prevent its feet from sinking into muddy riverbanks and, accordingly, the animal might have collected aquatic weeds and unlucky fish from the water’s edge.

9. Apparently, a Few Specimens Became Tyrannosaur Chow. 

Bite marks (presumably) belonging to Tarbosaurus bataar—a carnivore so similar to T. rex that some believe it should be reclassified as a species of Tyrannosaurus—are clearly visible on a few Deinocheirus bone fragments.

10. Some Priceless Deinocheirus Material Was Poached and Nearly Lost.

When Canadian paleontologist Phil Currie came upon an incredibly rare Deinocheirus specimen in 2009, he soon realized that somebody else had gotten to it first. The site was in shambles, with trampled fossils strewn about haphazardly and even a bit of money tucked away beneath a nearby stone. Sadly AWOL were—among other things—this Deinocheirus’ skull and feet. However, word of Currie’s find soon got out, and before long, the scientist was contacted by a European collector who’d acquired some very intriguing fossils that, lo and behold, turned out to be the missing pieces in question.  

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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