New Study Uses Stomach Stones to Suggest Dinosaur Migrations
Written by Andrew-Rossi on March 17, 2021
Research suggests millions of years ago, migrating dinosaurs traveled to Wyoming on a full stomach of stones from hundreds of miles away.
Research conducted by scientists at the University of Texas discovered new information on the life and times of Jurassic dinosaurs in Wyoming. But the discovery didn’t come from dinosaur bones – it came from dinosaur stones.
Gastroliths are smooth, shiny stones often found next to the skeletons of long-necked dinosaurs like Brontosaurus. They called trace fossils – not bones or teeth, but something left behind by a prehistoric creature. Footprints and coprolites – fossilized poop – are other examples of trace fossils.
Long-necked dinosaurs had no chewing teeth in their jaws – they bit and swallowed their exclusively plant diet. To help digest tough vegetation, paleontologists believe they swallowed small stones to grind plants inside their guts.
These stones, scientifically called gastroliths, are often found next to the bones of plant-eating dinosaurs. They are completely unlike any other rocks in a dig site. This leads paleontologists to believe the dinosaurs died with stones in their stomachs.
It sounds strange but it’s actually common. Modern animals like crocodiles, birds, and seals also swallow stones to help digest their food.
It was these stomach stones at a dinosaur excavation site in the eastern Bighorn Basin that revealed another secret of the dinosaurs’ world.
Joshua Malone, a geoscience researcher at the University of Texas at Austin, and other scientists studied the detrital zircon age spectra of Jurassic dinosaur gastroliths. This information reveals the origins of the stones thru microscopic crystals inside.
That data revealed the stones found in Wyoming came from over a thousand miles away – the location of present-day Wisconsin. It shows that 150 million years ago, long-necked dinosaurs went on long migrations, likely to appease their eternally large appetites.
Once they got to Wyoming, they died with gastroliths still inside their guts or possibly regurgitated them back up. Regardless, that’s how prehistoric Wisconsin stones ended up in modern-day Wyoming.
Trace fossils like gastroliths often provide excellent ideas on how dinosaurs and other prehistoric animals lived. Sometimes, these fossils provide even more information than fossilized bones.
It’s yet another example of how Wyoming is one of the most important areas in the world for the study of paleontology. Even its smallest stones can share big secrets of the past.
Courtesy University of Wyoming Geological Museum
