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| Artist's impression of Revueltosaurus callendari [Credit: Petrified Forest National Park] |
Or perhaps they lived in burrows amid the ferns, mosses and 20-foot-tall horsetails.
They were about 3 feet long, about the size of a modern-day Komodo dragon.
Something came along and wiped out 11 of them at once in the same location -- perhaps some big event like a major flood, said Bill Parker, park paleontologist.
These are some of the finds on 26,000 acres of a former ranch the national park purchased last year under a 2004 approval from Congress.
The creatures were first found near a creek in New Mexico, but this is the most complete collection of them.
It was thought they were plant-eating dinosaurs, but they weren't.
"We realized that it wasn't a dinosaur. It was a whole new family of reptile that no one had ever seen before," Parker said.
It had iguana-like teeth good for eating plants and maybe insects or small animals, measured 4 to 5 feet long and had armored portions along some of its body.
"It was a one-time event that killed them, and all those animals were together for some reason," Parker said.
Digs abound
There are a number of digs going on out at Petrified Forest these days.
The Smithsonian Institution is checking out remains of the earliest mammals known in what is now northern Arizona.
They date from 200 million years ago, when North America was fused with what is now Europe and South America in a mass called Pangaea.
Yale University is investigating an armored, slow-moving vegetarian dinosaur, 15 or 20 feet long.
Baylor University researchers have spent four years analyzing soil layers to re-create rainfall and temperature records for periods 200 million to 220 million years ago.
Parker and others have about 40 more square miles to investigate now, with a dozen archaeological sites already known.
Source:Arizona Daily Sun [September 27, 2012]