Dinosaurs were massive creatures that ate a lot of food. How did they manage coexisting with other dinosaurs without fighting over that food?
Researchers at the University of Bristol and London's Natural History Museum now have an answer. Sauropods, such as Diplodocus and Brachiosaurus, coexisted because different species ate different kinds of food. This kept competition for food to a minimum so that dinosaurs could live peacefully with each other.
These dinosaurs lived in the western part of the United States that paleontologists call the Late Jurassic Morrison Formation. Paleontologists believe that over 10 species of sauropods lived there at any given time.
However, these dinosaurs were massive, weighing up to 80 tons, and ate a lot of plants. Their heads were also small, at least in comparison to their bodies, so these two factors bewildered scientists. How exactly did these creatures live together in this area and how and what did they eat?
Researchers began by using CT scans for reconstructing models of dinosaur heads, focusing on the skull and jaws of two specific sauropods, Camarasaurus and Diplodocus. Researchers chose these two species because both lived near the Jurassic Morrison Formation, where they coexisted.
A computer model showed how those skulls and jaws functioned when taking in and ingesting food. According to the simulation, neither dinosaur could chew, but they had strong bites. The Camarasaurus probably fed on harder leaves and branches, but the Diplodocus ate softer plants, and used its long neck to tear leaves from their sources.
"This indicates differences in diet between the two dinosaurs, which would have allowed them to coexist," says study co-author Dave Button from the University of Bristol.
After creating computer models of other sauropods, the research team discovered that each species ate different plants. This means that there was no competition between species for food.
However, this wasn't always the case. At one point in history, sauropods ate multiple plant types. However, scientists believe evolution assisted coexistence among species.
"Our study provides insight not only into the ecology of dinosaurs but more generally into the mechanisms supporting species-richness in other animal communities, both from the fossil record and in the present-day," says study co-author Paul Barrett of the Natural History Museum.
Modern animal communities also eat in this way, allowing for coexistence. Although scientists previously believed this is why sauropods lived peacefully together in the Jurassic Morrison Formation, this is the first time that research has proven why.
