Faeces, vomit, and fossilised food from inside stomachs have provided new clues into how dinosaurs rose to dominate Earth, a new study revealed. The researchers at Sweden’s Uppsala University, led by Martin Qvarnstrom, discovered over 500 fossilised remains of dinosaur faeces, vomit, and undigested food inside intestines from sites in Poland. Using new technology such as synchrotron microtomography, they built 3D images of the samples, which revealed that the excrement contained the remains of insects, plants, fish, and bigger animals.
The researchers compared this data with information about fossils, plants, and the climate to construct a model for the step-by-step rise of the dinosaurs. They found that the excrement tripled in average length and width over the 30 million-year period, demonstrating how the animals that digested, vomited, or excreted these remains tripled in size over that time. Some of the fossilised remains belonged to an early ancestor of dinosaurs, the Silesaurus, which was a small, omnivorous animal that ate insects, fish, and plants.
The study suggested that the Silesaurus’s ability to adapt to sudden changes in the environment, such as a rainy period that led to the evolution of new plants, gave it an advantage over its rivals. As the smaller dinosaurs grew bigger from this new diet, so did larger carnivores that fed on them. By the time the Jurassic period rolled around, the landscape was dominated by giant plant-eating dinosaurs and ferocious carnivores.
The study will not settle the debate about what led to the rule of dinosaurs once and for all, but it provides a new perspective on the topic. The researchers suggested that it was a combination of early dinosaurs’ evolutionary advantages and environmental upheaval that killed off many of the previously dominant animals, creating an opening at the top. Further research is needed to fully understand the rise of the dinosaurs.
