Scientists Study Roadkill to Learn About Dinosaurs

first_imgStay on target For most paleontologists, a typical day in the field is serene, reflective, and generally odorless.For a team of excavators from Chicago’s Field Museum, however, it involves scraping swamp rabbits and armadillos off the Louisiana highway.“We want to know what the dinosaurs ate and what their habitats were like, but before we can do that, we need to understand what their environment was like,” according to study author Thomas Cullen, a postdoctoral researcher at the natural history museum. “We need to look at similar environments today.”More specifically, they need to look at the chemical makeup of remains of animals living in similar environments today.“You are what you eat, more or less,” Cullen said in a statement, before launching into a scientific explanation.Different plants contain different relative amounts of heavy or light stable isotopes—naturally occurring variants of elements. When animals eat those plants—or eat other animals that eat those plants—they absorb the isotopes into their tissue.Luckily for Cullen & Co., stable isotopes don’t necessarily deteriorate with death or fossilization. In fact, those preserved in the bones or teeth can stay intact for tens of millions of years, providing a glimpse into the lives of dinosaurs.“We wanted to check if the stable isotope methods that we typically have available really work for dinosaur paleontology, and particularly for characterizing ancient wetland ecosystems,” Cullen said. “So, we checked those methods in a modern coastal floodplain forest ecosystem where we already roughly know the right answers.“It was a due diligence exercise, and it involved playing with a lot of roadkill.”Driving around Louisiana’s Atchafalaya River Basin, the group picked up corpses “between meetings” with the state’s Department of Wildlife and Fisheries.“We didn’t really expect it to be too successful, but it actually ended up being super effective,” Cullen admitted. “We collected something like 40 [to] 50 samples representing about 15 species in the first couple days.”“The first few were really gross,” Cullen explained, recalling a particularly revolting experience with a dead racoon. “But we got desensitized.”Dozens more road-side carcasses followed, along with specimens provided by universities and museums, donated from local naturalists, and presented by Swamp People‘s Landry family.Back at the lab, the team analyzed tissue samples, only to find the results “a little fuzzy.” Without prior knowledge of what racoons and alligators eat, the isotope-based analysis would not have been precise enough to work.“Ideally, you’d be able to distinguish each animal by what it was eating and where in the habitat it was living,” Cullen said. “With fossils, we can’t go out and watch what an animal’s eating or exactly what habitat it prefers, so we should be conservative with our interpretations from this sort of data.”The study of stable isotopes should not be ruled out, though. More exotic systems than oxygen and carbon may yield better results.Read more details of the study, published last week in the journal Royal Society Open Science.More on Species of Tiny Tyrannosaur Sheds Light on T. Rex RelativeNew Dinosaur Species With Spiny Backbone Discovered in PatagoniaAsteroid Impacts Increased Around Time of Largest Extinction Event Scientists Uncover New Evidence of Asteroid That Killed DinosaursEgg Fossils Provide Glimpse Into Prehistoric Parenting last_img