Imagine a bird that is eleven feet long and five feet tall at the hip. Like many birds it has a small head, feathers and long spindly legs. But it also bore some resemblance to reptiles, like long arms tipped with sharp claws and a long bony tail. Weighing it at 500 pounds, this is one big chicken.
Meet Anzu wyliei, aka, “The Chicken from Hell.”
“It would look something like if you were to make an unholy fusion of a velociraptor and an ostrich,” Matt Lamanna said, assistant curator at the Carnegie Museum of Natural History and lead researcher of a new article that describes this rare bird in the journal PLOS One. Anzu walked the earth between 68 to 66 million years ago in the Rocky Mountain region of North America.
“The name ‘Chicken from Hell,’ it’s not exactly right,” Lamanna said. “It wouldn’t have looked exactly like a chicken. But it would have looked something like a giant, really freaky bird.”
Three specimens of anzu were unearthed in the Hell Creek Formation in South Dakota and North Dakota in the late 1990’s and the mid 2000’s. It belongs to a class of dinosaurs called the oviraptorosaurs, which exhibit characteristics of both reptiles and birds. They are closely related to the ancestors of birds, but they are not quite birds themselves. Most of the oviraptorosaurs are found in China and Mongolia, but one branch of the family tree reached North America to produce creatures like anzu.
“Unfortunately, this North American branch had been very poorly known, known from really, really fragmentary fossils from most of its history until the discovery of Anzu wyliei and now we have a nearly complete skeleton of one of these animals,” Lamanna said.
Lamanna said he and his research team puzzled over what anzu ate. After looking at its anatomy, they decided it was an “ecological generalist.” In other words, anzu filled several niches in its environment.
“It might have eaten plants a lot of the time,” Lamanna said. But anzu’s menu was not entirely vegetarian. “If, say, a small animal like a lizard or a mammal were to run by, it probably wouldn’t have hesitated to grab it and snatch it up and eat it.”
Anzu’s contemporaries included triceratops, duck-billed dinosaurs like edmontosaurus, thick-headed dinosaurs such as pachycephalosaurus, and armored dinosaurs like ankylosaurus. The top of the food chain at the time was the most famous dinosaur of all, tyrannosaurus rex.
“As big as anzu was, I think to a T-rex it would look like a Chicken McNugget from hell,” Lamanna said.
Lamanna said the discovery of anzu is significant because the North American branch of the oviraptorosaurs had puzzled paleontologists for nearly a century because fossils had been incomplete. They had bits and pieces – a pair of hands here, a complete lower jaw there – but no complete skeleton. Lamanna said scientists can do a better job now at painting a vivid picture of physical and biological characteristics of North American oviraptorosaurs.
For Lamanna, anzu is exciting because “it’s just an awesome dinosaur.” Furthermore, paleontologists have been exploring the Hell Creek Formation for more than a century and it is one of the most productive fossil-producing areas in the world. But it is still uncovering its secrets.
“The fact that this 500 pound thing, this 10 foot long thing, this very distinctive looking thing, remained hidden for almost a century just kind of illustrates what else might be out there,” Lamanna said.
If these types of discoveries are still possible in well-explored places like the Hell Creek Formation, Lamanna said, just imagine the potential in less-explored areas like southern South America, Australia and Antarctica.