March 24, 2010

New Dinosaur Species Discovered in Utah Desert

A new species of plant-eating dinosaur has been discovered in the Navajo Sandstone region of Utah, where it apparently had been buried by a collapsing sand dune, researchers announced on Tuesday.

According to a March 23 University of Utah press release, the nearly complete skeleton is of a plant-eater that lived approximately 185 million years ago.

It was discovered in 2004, excavated in 2005, and is the topic of research published in PLoS ONE, the online journal produced of the Public Library of Science.

It has been dubbed Seitaad ruessi and classified as a sauropodomorph, a suborder of herbivores that were believed to be the largest animals to ever walk the Earth.

Seitaad ruessi is the first dinosaur discovered in Navajo Sandstone country, and is one of the oldest known species found in the entire state. It stood approximately three to four feet tall, was 10 to 15 feet long, and weighed between 150 and 200 pounds, on average.

It is believed to have been one of the first North American sauropodomorphs during its era, and was closely related to species discovered in South America and Africa.

The remains were discovered by Joseph Sertich, a doctorate student at Stony Brook University in New York, and Mark Loewen, a paleontologist at the Utah Museum of Natural History and instructor in the University of Utah's Department of Geology and Geophysics.

The name was derived from the Navajo word for a legendary desert monster (Seit'aad) and the last name of explorer and naturalist Everett Ruess, who vanished in the red rocks region of southern Utah in the 1930s.

"Although Seitaad was preserved in a sand dune, this ancient desert must have included wetter areas with enough plants to support these smaller dinosaurs and other animals," Sertich noted in the press release. "Just like in deserts today, life would have been difficult in Utah's ancient 'sand sea.'"

"We know from geologic evidence that seasonal rainstorms like today's summer monsoons provided much of the moisture in this sand sea, filling ponds and other low spots between the sand dunes," added Loewen.


Image 1: This is the fossil of the new dinosaur species Seitaad ruessi. Credit: Utah Museum of Natural History, University of Utah.

Image 2: The discovery of the new plant-eating dinosaur was just below an ancestral Puebloan (Anasazi) cliff-dwelling called Eagles Nest in the in the Comb Ridge area near Bluff, Utah. Credit: Utah Museum of Natural History, University of Utah.


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