A new analysis of fossil faeces has revealed what the environmental conditions were like at the time dinosaurs started to take over the Earth.
Researchers found undigested remains of food, plants and prey, in the samples of fossilised faeces, providing clues about the role played by dinosaurs in the ecosystem around 200 million years ago.
The study, published in the journal Nature, focussed on the unexplored northern parts of the then-supercontinent Pangea.
While much is known about the lives and extinction of dinosaurs, the processes that led to their rise are largely unexplored.
Researchers developed a picture of the Triassic and Jurassic ecosystems from 230 to 200 million years ago by combining insights from the faeces analysis with climate data and information from other fossils, including bite marks, footprints and bones.
The new findings address a 30-million-year gap in our knowledge of dinosaur evolution during the first part of the Late Triassic period.
“The research material was collected over 25 years. It took us many years to piece everything together into a coherent picture,” study co-author Grzegorz Niedźwiedzki said.
Researchers used advanced imaging techniques to visualise the hidden, internal parts of the fossilised faeces, called coprolites, in detail.
In these coprolite structures, they found remains of fish, insects, larger animals and plants, some of them unusually well preserved, including small beetles and semi-complete fish.
Some samples also had coprolites containing remains of bones chewed up by predators to salts and marrow much like modern-day hyenas.
Researchers were particularly surprised by the contents of coprolites from the first large herbivore dinosaurs, like the long-necked sauropods.
In these samples, they found large quantities of tree fern remains as well as other types of plants and charcoal.
These dinosaurs may have consumed charcoal to detoxify their stomach contents as ferns can be toxic, researchers said.
Overall, the findings suggest dietary diversity and adaptability were key survival traits that helped dinosaurs overcome environmental changes during the Late Triassic.
“The way to avoid extinction is to eat a lot of plants, which is exactly what the early herbivorous dinosaurs did. The reason for their evolutionary success is a true love of green and fresh plant shoots,” Dr Niedzwiedzki concluded.
