Paleontologists have long puzzled over how dinosaurs, originally relatively small and unimportant to the broader ecosystem, evolved into a major species some 30 million years later. Fossilized dinosaur feces and vomit may contain important clues to how and why this evolutionary milestone arose, according to a new paper published in the journal Nature It is said that there is.
Co-author Martin Kvarnström, an evolutionary biologist at Uppsala University in Sweden, and his colleagues studied trace fossils known as . bromalitea specification containing. coprolite The same goes for vomit and other fossilized material from the digestive tracts of living things. As previously reported, fecal lights are old fecesretains many organic components that can be reconstituted and analyzed for chemical properties. Since coprolite is a fossil, most of its organic components have been replaced by mineral deposits such as silicates and calcium carbonate.
Coprolites and ancient Feces can be a veritable treasure trove of information. For example, in 2021 we reported: Analysis of preserved paleofeces It turns out that ancient Iron Age miners in what is now Austria loved beer and blue cheese.
If a coprolite contains bone fragments, the animal that excreted it is likely a carnivore, and the tooth marks on those fragments indicate how the animal ate its prey. It could tell us something about The size and shape of coprolites can also provide useful insights. For example, if the coprolite is spiral-shaped, the coprolite may have been excreted by an ancient shark, since some modern fish (such as sharks) have spiral-shaped intestines.
A tale of two models
Excavations in the Late Triassic area of Lisowice, Poland. Large quantities of feces from predators and herbivores were found at this site.
Credit: Christian Barranda
Kvarnström et al. They identified two competing hypotheses for the rise of dinosaurs from the late Triassic period (237 million to 201 million years ago) to the beginning of the Jurassic period, 201 million to 145 million years ago. I was eager to verify. “No single hypothesis seems to fully explain the emergence of dinosaurs, and the important question of how dinosaurs established dynasties on land remains largely unanswered,” the authors wrote in their study. I’m writing about purpose.
One hypothesis cites evolutionary competition (the traditional “competitive substitution” model) as a driving factor, with dinosaurs being better equipped to survive thanks to superior physiology, anatomical adaptations, and feeding habits. He says he is getting better. Alternatively, the “opportunistic replacement” model suggests that dinosaurs were influenced by random processes, i.e., rapidly changing environments brought about by volcanic eruptions, climate change, or other catastrophic events that led to the decline or extinction of other species. This suggests that they have adapted well.
