How Dinosaurs Ate So Much and Still Coexisted: Dividing Up Leafy Meals

When dinosaurs roamed the Earth, they fed and lived alongside one another. Yet how did such massive creatures manage to live with each other without eating all of their resources? Scientists have now taken a closer look at how dinosaurs fed and allocated resources.

Between 210 and 65 million years ago, large, long-necked plant-eating dinosaurs known as sauropods dominated the planet. These were the largest land animals of all time with the largest weighing as much as 80 tons. Needless to say, these animals consumed vast amounts of food. However, they still lived alongside one another.

Now, scientists have taken a closer look at how these dinosaurs coexisted. While sauropods were gigantic, their heads were comparatively small. How they ingested food, therefore, has long puzzled scientists. In this case, the researchers examined the skull and jaws of sauropods and used a variety of biomechanical techniques to see how they functioned and what this would mean for sauropod ecology.

The scientists used CT scans to digitally reconstruct the skulls of sauropods, Camarasaurus and Diplodocus, along with the jaw and neck muscles of both species. These two species widely coexisted, which made them a perfect pair for study.

"Our results show that although neither could chew, the skulls of both dinosaurs were sophisticated cropping tools," said David Button, one of the researchers, in a news release. "Camarasaurus had a robust skull and strong bit, which would have allowed it to feed on tough leaves and branches. Meanwhile, the weaker bit and more delicate skull of Diplodocus would have also have used its strong neck muscles to help it detach plant material through movements of the head. This indicates differences in diet between the two dinosaurs, which would have allowed them to coexist."

The scientists also used a series of biomechanical measurements from other sauropod species. This showed that other sauropods were also highly varied in feeding adaptations, which showed that they had different diets.

"Our study provides insight not only into the ecology of the dinosaurs but more generally into the mechanisms supporting species-richness in other animal communities, both from the fossil record and in the present-day," said Paul Barrett, co-author of the new study.

The findings are published in the journal Proceedings of the National Academy of Sciences.