Scary ‘chicken’ roamed Earth with T. rex | Science News for Students

Scary ‘chicken’ roamed Earth with T. rex

Scientists discover terrifying, birdlike dino
Mar 28, 2014 — 7:00 am EST

This freakish reptile might have been among the last surviving dinosaurs. Its remains turned up in the Hell Creek Formation, a rocky area in the U.S. West rich in dinosaur fossils.

Mark Klingler, Carnegie Museum of Natural History

Last week, scientists announced the discovery of a new birdlike dinosaur. With feathers, a beak and spindly legs, it looked pretty ridiculous. But you’d be scared silly running into this creature. The reptile spanned 3 meters (10 feet), would have towered over most humans (had they existed back then), and would have tipped the scales at 226 kilograms (500 pounds). Oh, and it had sharp claws — ones that could have ripped you to shreds.

Fossil hunters unearthed the bones of this species in a rocky area of southwest North Dakota. This geological formation is known as Hell Creek. Not surprisingly, then, the scientists have nicknamed this beast the “Chicken from Hell”.

They also gave it a more formal name: Anzu wyliei. Anzu was a mythical fire-breathing bird. Wylie is the dinosaur-loving grandson of a man who supports the Carnegie Museum of Natural History in Pittsburgh, Pa. Scientists at that museum were part of the team that described the new dino in a paper published March 19 in the journal PLOS ONE.

“The Anzu dinosaur is based on a spectacularly nice specimen,” John Hutchinson told Science News for Students. A biomechanist who did not take part in the research, he works at the University of London’s Royal Veterinary College. Past digs had turned up hints of this animal, he says, “but nothing this slam-the-case-shut conclusive.”

Giant puzzle

Imagine finding several jigsaw pieces yet being unsure what picture they’ll portray, how many pieces remain or where those missing pieces are. That’s a challenge faced by many paleontologists. They collect and scrutinize ancient bones and other remains to learn about creatures that roamed Earth millions of years ago.

Two different groups of fossil hunters ran across some strange bones in the late 1990s. One team discovered two skeletons in South Dakota. Meanwhile, Tyler Lyson — then a high school student — stumbled across several bones on his uncle’s North Dakota ranch. All these dino hunters had been scouring the Hell Creek Formation. It’s known for being loaded with remnants of famous dinos such as Tyrannosaurus rex and Triceratops.

“I knew when I found the specimen that it was something new,” Lyson recalls. Since the age of 6 he had spent summers digging for fossils. “It looked like a meat-eating dino,” he notes. “They have hollow bones whereas plant eaters do not.” And he should know. He is now a paleontologist at the Smithsonian Institution’s National Museum of Natural History, in Washington, D.C. He also was part of the team that pieced together Anzu.

In 2004, the South Dakota fossil hunters sold their collection of several hundred dino bones to the Carnegie Museum. For a while, those bones just collected dust while the staff was busy rebuilding the museum’s dinosaur exhibit.

Then, at a 2006 paleontology conference in Canada, the Carnegie scientists spotted an intriguing poster. It described a set of seven bones dug up from the same Hell Creek area. The bones resembled the dino specimens the museum had purchased years earlier. That poster described research by Lyson and Emma Schachner, an evolutionary biologist at the University of Utah in Salt Lake City.

“We all realized we probably had the same animal,” says Matt Lamanna. He’s a Carnegie paleontologist. With their busy schedules, it took another eight years for all of the scientists to merge their specimens and formally describe how Anzu’s bones fit together.

The animal was a theropod — a meat eater that walked on two legs and lived during the late Cretaceous Period, about 67 million years ago. The newfound species is the largest of a group of North American birdlike dinos called oviraptors. That term is Latin for egg thieves.

But Anzu is far from the biggest oviraptor ever. That prize goes to the 1.4-ton Gigantoraptor that had lived in what is now northern China. It came to scientists’ attention in 2005.

Oviraptors that looked similar to Anzu appear in the 2013 3D documentary, Walkingwith Dinosaurs, notes Thomas Holtz, who did not work on the recent study. He is a vertebrate paleontologist at the University of Maryland.

Imagining what these animals’ lives were like “is a fun mystery,” Hutchinson says. He and other scientists use computer programs to calculate how fast dinosaurs likely moved and what they might have eaten.

With a birdlike beak and no teeth, Anzu probably was not a top predator. But the species' long and skinny hind legs might have let the dinos race across the landscape at speeds of 48 to 65 kilometers per hour (30 to 40 miles per hour). Quips Lamanna, “We don’t call it Hell’s Chicken for nothing.”

Power Words

biomechanist    A scientist who studies how living things move. For humans or other large animals, this might involve analyzing the forces exerted by muscles, tendons and gravity on an individual’s skeletal (or other supporting) structures.

Cretaceous Period  A geologic time period that included the end of the Age of Dinosaurs. It ran from roughly 145.5 million years ago until 65.5 million years ago.

dinosaur   A term that means terrible lizard. These ancient reptiles lived from about 250 million years ago to roughly 65 million years ago. All descended from egg-laying reptiles known as archosaurs. Their descendants eventually split into two lines. They are distinguished by their hips. The lizard-hipped line became saurichians, such as two-footed theropods like T. rex and the lumbering four-footed Apatosaurus (once known as brontosaurus). A second line of so-called bird-hipped, or ornithischian dinosaurs, led to a widely differing group of animals that included the stegosaurs and duckbilled dinosaurs.

evolutionary biologist   Someone who studies the adaptive processes that have led to the diversity of life on Earth. These scientists can study many different subjects, including the microbiology and genetics of living organisms, how species change to adapt, and the fossil record (to assess how various ancient species are related to each other and to modern-day relatives).

Gigantoraptor   A dinosaur whose remains were unearthed in northern China. The largest oviraptor known, it would have weighed about 2 tons and stood more than 5 meters (greater than 16 feet) tall.

oviraptor     A genus of meat-eating dinosaurs that walked on two legs. They lived between 68 million and 66 million years ago in what is known as the Cretaceous period.

paleontologist     A scientist who specializes in studying fossils, the remains of ancient organisms.

poster    (in research) New research that is presented in a visual display at a scientific meeting. The data are reported in graphs, tables or other types of displays. Typically, the findings and the researchers’ tentative conclusions will be printed on a large sheet of paper (often 1-by-1.5 meters, or about 3-by-5 feet in size) that is thumb-tacked onto huge cork boards. At some meetings, more than 500 posters may be presented per day. At least one author must stand by the poster for at least a few hours, ready to explain his or her findings (or answer any questions) to other scientists passing by.

predator  (adjective: predatory) A creature that preys on other animals for most or all of its food.

theropod  A meat-eating dinosaur of a group whose members are typically bipedal (walk on two legs) and range from small and delicately built to very large.

Tyrannosaurus rex  A top-predator dinosaur that roamed Earth during the late Cretaceous period. Adults could be 12 meters (40 feet) long.

vertebrate  The group of animals with a brain, two eyes, and a stiff nerve cord or backbone running down the back. This group includes all fish, amphibians, reptiles, birds, and mammals.


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Further Reading

S. Perkins. “Reviving dinosaurs.” Science News for Students. Mar. 4, 2014.

S. Perkins. “Early tyrannosaurs would have feared this predator.” Science News for Students. Dec. 9, 2013.

J. Raloff. “King of Gore.” Science News for Students. Nov. 7, 2013.

E. Sohn. “A big, weird dino.” Science News for Students. June 22, 2007.