Scitech  Digging for dinosaurs

Utahceratops, Kosmoceratops, and other fossils

Two dinosaurs struck forth into the fresh light of public awareness on September 22, 2010, in the online journal PLoS One. Utahceratops and Kosmoceratops were both found in the Grand Staircase Escalante National Monument, a high desert terrain in Southern Utah. Like their closely related famous cousin, the Triceratops, both bear a large horn on their nose and both have sideways projecting eyehorns. Kosmoceratops can boast of having the most elaborately ornate head of all known dinosaurs, with fifteen horns strewn over the nose, eyes, cheeks, and frill. After interviewing three of the main investigators, Scott Sampson and Mark Loewen, both researchers at the Utah Museum of Natural History, and Andrew Farke, of the Raymond M. Alf Museum of Paleontology in California, I gained many insights into the actual process of discovering dinosaurs.

Before the digging begins, paleontologists work with geologists to find regions of exposed rock from the Mesozoic period, the age of dinosaurs. Rocks deposited on land tend to be more promising than those in the ocean, since dinosaurs were terrestrial creatures. Eventually, their suspicion falls on a particular chunk of sediment that may contain a dinosaur bone.

“Scientists use a variety of tools to remove the rock from above the fossil, including gas-powered rock saws and jack hammers,” explained Sampson. “They then use finer tools, like brushes and dental picks, to expose some of the bones before covering them in a protective jacket of plaster and burlap. The specimens are then carried back to a preparation lab where the rock is removed and the fossils are stabilized with glue.”

Once enough bones are dug up, experts compare their shapes to those of other dinosaurs, or even of modern animals, to help get an idea of what the dinosaur might have looked like and to fit the skeleton together. Paleontologists also compare the unique kinds of spikes, horns, crests, and other bony accoutrements of the new dinosaur with previously discovered dinosaurs to determine if it is an entirely new species.

Scientists try to figure out the specific ages of the dinosaurs using a technique similar to carbon dating. In carbon dating, the radioactive carbon breaks down and halves its mass after a set period of time, its half-life. But carbon only has a half-life of 200,000 years – not nearly long enough to reach back into the time of dinosaurs. Fossils can be dated with elements with much longer half-lives, like argon, potassium, and uranium.

New discoveries like these often lead to some of the rich rewards of science: new hypotheses. In Farke’s work, after looking at the patterns of injuries across the skulls of certain horned dinosaurs, he and his team posited that some of them “used their horns for fighting each other, members of their own species.”

In a different case, Sampson’s team had revealed a large carnivorous dinosaur in Madagascar, which happened to be closely related to a species in Argentina. Thus it was proposed that there were once connections linking Africa and South America, via Antarctica; dinosaurs could have walked through this corridor to the other side, as there was no ice on Antarctica during their era.

Veering back to our own era, dinosaurs are now unearthed more quickly than many of us may think. Across the globe, dozens are discovered every year. Utah itself yields one or two a year, owing in particular to the new, largely unexplored region of the Grand Staircase Escalante National Monument.