'Chicken from hell' dino no match for T. rex

Saturday, May 23, 2015

 Chicken coup: A reconstruction of Anzu wyliei in its 66-million-year-old environment in western North America.(Source: Mark A Klingler/Carnegie Museum of Natural History)

Will Dunham

A giant, 200-kilogram "chicken from hell" that resembles an Australian cassowary roamed Dakota at the same time as T. rex, US scientists reveal today.

And while the "weird-looking" bird may have eaten the odd mammal, it would have been chips for this chicken if it had crossed T. Rex's path.

The revelation comes as another team of researchers has unveiled 126-million-year-old fossils, found in China, of the oldest-known stick or leaf insect.

The chicken-like dinosaur, Anzu wyliei , had a head shaped like a bird's, a toothless beak, hands with big sharp claws, long legs for fast running and was probably covered in feathers.

A bizarre crest on its head is similar to that found on the cassowary, a flightless bird native to Australia and New Guinea.

Anzu wyliei measured about 3.5 metres long, 1.5 metres at the hip and weighed about 200-300 kilograms, the researchers say.

"It has the nickname 'the chicken from hell'. And that's a pretty good description," says palaeontologist Dr Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh, who led the research published in the journal PLOS One.

"If you could get in a time machine and go back to western North America at the end of the age of dinosaurs and see this thing, I would say your first reaction might be, 'What a weird-looking bird'," Lamanna says. "It would not look like most people's conception of a dinosaur."

On the menu

It is the largest North American example of a type of bird-like dinosaur well known from Asia. Its extensive remains offer a detailed picture of the North American branch of these dinosaurs that has remained mysterious since their first bones were found about a century ago, the scientists say.

Fossils of feathers are extremely rare and they were not found with any of the three partial skeletons of Anzu wyliei. But the researchers believe it had feathers based on fossils of close relatives from China that have clear evidence of them.

A. wyliei lived at the sunset of the age of dinosaurs, not long before an enormous meteorite is thought to have struck Earth about 65.5 million years ago and wiped them out along with hordes of other creatures, while sparing many birds.

It lived in a humid, low-lying environment dotted with rivers and swamps and lush with vegetation and plant-eating dinosaurs like the horned Triceratops, armoured Ankylosaurus, dome-headed Pachycephalosaurus and duck-billed Edmontosaurus.

But also hanging around the neighbourhood was one of the fiercest predators in Earth's history, Tyrannosaurus rex.

A. wyliei may have been an omnivore, munching on leaves, fruits or flowers while also swallowing the occasional mammal foolish enough to cross its path, the researchers say.

But it probably needed to be careful not to end up on someone else's menu.

"To a T. Rex, this thing would not look like a 'chicken from hell'. It would look like lunch," Lamanna says.

Ancient camouflage

Also in PLOS One today an international team of scientists has released details of its discovery in China of the fossil of an insect that lived about 126 million years ago whose appearance mimicked that of a nearby plant.

It is the oldest-known stick or leaf insect that used such natural trickery, the team says.

The insect, named Cretophasmomima melanogramma, was found in Liaoning province in northeastern China, part of the Jehol rock formation that has yielded many stunningly detailed fossils of creatures like early birds and feathered dinosaurs.

The researchers realised the insect looked remarkably like the leaf of a plant that grew in the same place at the time that was a relative of the Ginkgo tree.

The fossil shows wings with parallel dark lines that, when the bug was in the resting position, seem to produce a tongue-like shape that could hide its abdomen, they say. The plant had similar tongue-shaped leaves marked with multiple lines.

The researchers think the insect evolved to look like these leaves - even their green colour - and concealed itself from predators by mingling with the foliage. Females of this insect were estimated at about 55 millimetres long and the males a bit smaller.

"Cretophasmomima melanogramma is one of the grand-cousins of today's stick and leaf insects," says one of the researchers, Dr Olivier Bethoux of the Centre for Research on Palaeobiodiversity and Palaeoenvironments in the National Museum of Natural History in Paris.

There are roughly 3,200 known species of stick and leaf insects, which are members of the insect order known as Phasmatodea, derived from the ancient Greek word for phantom for their ability to seemingly disappear into the background.

Cretophasmomima melanogramma lived during the Cretaceous, the last of the three time periods that make up the Mesozoic Era, sometimes called the Age of Dinosaurs.

The arrival of small insect-eating birds and agile, branch-walking mammals provided good reason for insects to develop new predator-avoidance strategies like mimicking the appearance of a leaf, Bethoux says.

The researchers say this insect lacked some characteristics of similar insects seen today, such as a curved part of the front legs that hide the head.

'Chicken from Hell' skeleton sheds light on 250kg feathered dinosaur Anzu wyliei

A 250-kilogram 'chicken from hell' with features similar to the cassowary is the latest dinosaur discovery by US scientists, who have named the "scary and absurd" creature after a mythical bird-like demon.

Almost a full skeleton of the sharp-clawed, crested raptor that roamed the Hell Creek rock formation in North and South Dakota 66 million years ago was pieced together from three different specimens.
They have named it Anzu wyliei: "anzu" after a bird-like demon in Mesopotamian mythology, and "wyliei" after Wylie J Tuttle, the dinosaur-loving grandson of a Carnegie Museums of Pittsburgh trustee.

"It was a giant raptor, but with a chicken-like head and presumably feathers. The animal stood about 10 feet tall, so it would be scary as well as absurd to encounter," says University of Utah biology postdoctoral fellow Emma Schachner, a co-author of a new study of the dinosaur.

Pieces of a strange-looking puzzle
Three partial skeletons of the dinosaur – almost making up a full skeleton – were excavated from the uppermost level of the Hell Creek rock formation in North and South Dakota, a formation known for abundant fossils of Tyrannosaurus rex and Triceratops.

At a scientific meeting in 2005, Matthew Lamanna of the Carnegie Museum of Natural History in Pittsburgh, Tyler Lyson of the Smithsonian in Washington and Dr Schachner realised they had fossils of the same new species of dinosaur.

They soon began collaborating on the new study and asked Hans-Dieter Sues to join them because he was an expert on this type of dinosaur.

"It took years since all of us had busy schedules, and I moved to Utah in 2010 to work on reptile respiratory evolution," says Dr Schachner.

Having a nearly complete skeleton of Anzu wyliei sheds light on a category of oviraptorosaur theropod dinosaurs named caenagnathids, which have been known for a century, but only from limited fossil evidence.

"I am really excited about this discovery because Anzu is the largest oviraptorosaur found in North America," she said.

"Oviraptorosaurs are a group of dinosaurs that are closely related to birds and often have strange, cassowary-like crests on their heads."

A dangerous life
Lead researcher Dr Lamanna says they call the creature the "chicken from hell".

And while it might look rather strange, the bones collected show that Anzu needed to be tough to survive.

Not only did it share the Hell Creek formation with the most notorious carnivore of all time, the T-rex, but Anzu seems to have been in some scrapes.

Two of the three specimens show clear evidence of injuries: one has a broken and healed rib, while the other has an arthritic toe bone that may have been caused by an avulsion fracture (where a tendon ripped a piece off the bone to which it was attached).

"These animals were clearly able to survive quite a bit of trauma, as two of the specimens show signs of semi-healed damage," says Dr Schachner.

"Whether these injuries were the result of combat between two individuals or an attack by a larger predator remains a mystery."

Much to learn
As much insight as the Anzu skeletons provide, paleontologists still have much to learn about North American oviraptorosaurs.

"We're finding that caenagnathids were an amazingly diverse bunch of dinosaurs," says Dr Lamanna.
"Whereas some were turkey-sized, others - like Anzu and Gigantoraptor - were the kind of thing you definitely wouldn't want to meet in a dark alley. Apparently these oviraptorosaurs occupied a much wider range of body sizes and ecologies than we previously thought.

"After nearly a century of searching, we palaeontologists finally have the fossils to show what these creatures looked like from virtually head to toe. And in almost every way, they're even weirder than we imagined."

By Cristen Tilley

Bizarre bat-winged dinosaur once soared over China

Wednesday, May 13, 2015

Artist's impression of the new dinosaur Yi qi. (Dinostar Co. Ltd)

Jennifer Viegas
Discovery News

A dinosaur with bat-like wings once soared through the skies of what is now China.
The Jurassic dinosaur, named Yi qi, has the shortest name ever given to a dinosaur. Yi qi, pronounced "ee chee," means "strange wing."

Yi qi also appears to be the earliest known flying non-avian dinosaur. At 160 million years old, it is older than the first known birds, such as Archaeopteryx.

"This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career," says palaeontologist Xu Xing of the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) in Beijing.

"I know the complexity of the dino-bird transition, but this new find still shocks me," adds Xu, who is the lead author of the study, published in the journal Nature.

"It demonstrates how extreme the experimentation for dinosaurs to get in air is."

He and his colleagues unearthed the remains for Yi qi at Hebei Province in China.

At first, the scientists puzzled over rod-like bones that extended from each wrist of the tiny dinosaur that weighed about the same as a modern pigeon. Colleagues joked that the dino used the bones as ski poles or giant chopsticks.

Co-author Corwin Sullivan, a Canadian palaeontologist now based at the IVPP, determined their real purpose after he pored over scientific literature on flying and gliding animals for a different project.
"I came across a paragraph in a textbook that said flying squirrels have a strut of cartilage attached to either the wrist or elbow to help support the flight membrane. I immediately thought, wait a minute, that sounds familiar!" says Sullivan.

Further investigation of Yi qi's remains uncovered patches of membranous tissue that covered its wings.

While the dinosaur did have feathers, they were more like hairs, bristles or streamers, and would not have been capable of forming good aerodynamic surfaces, Sullivan says.

Given the dinosaur's bat-like wings, "Yi qi was mainly gliding, perhaps in combination with a bit of awkward flapping," he adds.

The researchers believe Yi qi was a scansoriopterygid - a group of dinosaurs only known from China that were closely related to primitive birds, such as the Archaeopteryx.

Although the dinosaur shared traits with bats, it wasn't related to them, since bats are mammals. It therefore represents a striking example of convergent evolution.

Other unusual characteristics

Yi qi had other noteworthy characteristics, aside from its unusual wings.

Sullivan says that its arms were proportionally very long, with each arm ending in a hand that had three clawed fingers. One of the fingers was very elongated, with it and the other fingers helping to support the flight membrane.

Its head was small, but equipped with tiny peg-like teeth, which it probably used to eat prey such as insects, small mammals and lizards.

As for what might have eaten Yi qi, Xu said, "I would not be surprised to see some primitive tyrannosaurs around."

While some studies theorise that scansoriopterygids evolved to become birds, Xu and his team think otherwise. They instead place dromaeosaurids and troodontids closer to birds.

"Yi qi seems to have been part of a Jurassic radiation of small dinosaurs that were experimenting with different ways of becoming airborne," Sullivan says.

"All these dinosaurs were closely related to birds and, in fact, it's best to think of birds as just one group that emerged during that evolutionary radiation - a group that happened to be extremely long-lived and successful."

This story was originally published on Discovery News