Paleontologists working in the American Southwest have unearthed two new species of dinosaur. The 90-million-year-old specimens, unveiled yesterday at a press conference in Washington, D.C., hail from a period about which nearly nothing is knownthe so-called Cretaceous Gap, spanning the time from 105 to 75 million years ago.
Researchers led by Doug Wolfe, director of the Zuni Basin Paleontological Project, found the remains about a half-mile apart from one another in an area known as the Zuni Basin, near New Mexico's border with Arizona. One of the ancient beasts, a strange slothlike creature the team has dubbed Nothronychus, belongs to the class of dinosaurs that includes Tyrannosaurus and Allosaurus. (More specifically, the new herbivore is a member of a group of dinosaurs known as therizinosaurs, which until now have turned up only in China and Mongolia.) Unlike its carnivorous cousins, however, the one-ton Nothronychus subsisted on plants, judging from its relatively small head and tiny teeth. The other remains belong to an as-yet-unnamed coelurosaur, a small predator akin to dromaeosaurs and oviraptors. Both dinosaurs, scientists say, exhibit birdlike features and probably sported feathers.
"It's a very interesting fauna," Phil Currie of the Royal Tyrrell Museum of Paleontology in Alberta told Discovery News. "It's going to change a lot of perceptions [about dinosaur evolution]."