Research that used the analysis of fossilized feces recreated the structure of ecosystems during the time when dinosaurs came to dominate the planet, at the beginning of the Jurassic period.
Coprolites are fossilized feces that constitute a valuable source of data on the past and have been used to try to reconstruct the rise of dinosaurs, from a landscape dominated by non-dinosaur reptiles to one in which they were thriving.
Dinosaurs, according to the fossil record, evolved in the mid-Triassic period (between 247 and 237 million years ago), but their dominance in terrestrial ecosystems was only observed about 30 million years later, in the early Jurassic.
A study published by Nature recreated the structure of ecosystems at the time when dinosaurs began their success story, based on the analysis of fossilized samples of feces, in which undigested food, plants and remains of prey were identified, reported on Wednesday - the Efe agency fair.
These analyzes of hundreds of samples have provided clues about the role dinosaurs played in the ecosystem around 200 million years ago.
The team led by Uppsala University, Sweden, studied, using various techniques, 500 fossilized remains of digestive material (such as feces or vomit) from southeastern Poland, spanning from the end of the Triassic to the beginning of the Jurassic.
Analyzes of these remains were compared with the existing fossil record, along with climatic and plant data, to estimate changes in vertebrate size and abundance during this period.
"Our research is groundbreaking because we chose to understand the biology of early dinosaurs based on their food preferences. There were many surprising discoveries along the way," said Grzegorz Niedzwiedzki of Uppsala University and signatory of the study.
The coprolites contained the remains of fish, insects, larger animals and plants, some exceptionally well preserved, including small beetles.
Others contained bones chewed by predators who, like today's hyenas, crushed the bones to obtain salts and marrow.
The content of the coprolites of the first large herbivorous dinosaurs, the long-necked sauropods, surprised researchers, as there were large quantities of ferns, but also other types of plants and charcoal.
Paleontologists' hypothesis is that the charcoal was ingested to detoxify stomach contents, since ferns can be toxic to herbivores.
The study resulted in a five-step dinosaur evolution model that is applied to the geographic area of the samples but, according to the researchers, can explain global patterns.
The data suggests that non-dinosaur tetrapods were replaced by the omnivorous ancestors of the first dinosaurs, which evolved into the first carnivorous and herbivorous dinosaurs in the late Triassic.
Subsequent environmental changes related to increased volcanic activity may have led to a more diverse range of food plants followed by the emergence of larger and more diverse herbivorous species.
This led to the evolution of larger carnivorous dinosaurs in the Early Jurassic and completed the transition to their dominance in the ecosystem.
The results show that dietary diversity and adaptability were crucial traits for survival during Late Triassic environmental changes.
