North American dinosaurs may have migrated well over 100 miles with the seasons, scientists have discovered after a close look at their teeth.
A team led by Henry Fricke, a geochemist at Colorado College in Colorado Springs, studied the tooth enamel of Camarasaurus, a long-necked vegetarian sauropod that was common in western North America in the late Jurassic period, about 150 million years ago.
The enormous creatures would have had to eat constantly to sustain their size, and some dinosaur researchers suspected they would have had to migrate to find enough food and water, Fricke said. But they had no evidence.
Fricke and two former students, Justin Hencecroth and Marie Hoerner, drilled into 32 fossilized teeth found at Dinosaur National Monument and in Thermopolis, Wyo. They compared the ratios of oxygen isotopes within the enamel to that of soil samples near where the teeth were found.
The findings, published in the journal Nature, indicated that the dinosaurs had roamed within about 185 miles from where the fossils were found, Fricke said. Though the findings suggest that the dinosaurs traveled somewhere, they don’t indicate for how long or how often. That’s because the teeth had taken less than five months to grow, permitting examination of only five months of the creature’s life.
Camarasaurus
Chambered Lizard
Where it lived: Colorado, New Mexico, Utah and Wyoming
Length: 24 to 65 feet
Height: 15 feet tall at the hips
Weight: Up to 20 tons
When it lived: 155 to 145 million years ago
