Majestic. Thunderous. Powerful. Their mighty tread and sonorous cries once reverberated across our planet. And the rise of the dinosaurs to a dominance that lasted 165 million years has now been charted… in the fossilized poop and puke they left behind.
Yep, that’s right. By collecting hundreds of fossils of digested and undigested dino food – a category collectively known as bromalites – paleontologists have been able to give a more detailed look at the emergence of the dinosaurs with a level of detail we’ve never seen before.
Within this unorthodox digestive treasure trove, paleontologist Martin Qvarnström of Uppsala University in Sweden and his colleagues have managed to reconstruct dinosaur food webs in the Polish Basin 200 million years ago.
The results, they say, are a new tool for understanding how the dinosaurs lived and survived in a world so very unlike our own today.
“Our results confirm that the rise of dinosaurs was complex and unfolded gradually over 30 million years,” Qvarnström told ScienceAlert.
“It was influenced by a degree of opportunism (the first early dinosaur relatives and the first herbivores had a very generalized diet) but also competition. The dinosaurs were well-adapted and less vulnerable to the effects of climate change than many of their contemporaries.”
Bones tell us a lot about dinosaurs. We can reconstruct their skeletons and figure out what they may have looked like, how they lived, and what sort of diet they may have relied on.
But there’s a lot that bones can’t tell us. We don’t know the specifics of those diets, how they may have supplemented their staples, or how they may have competed for resources.
Bromalites, Qvarnström and his team realized, might be an untapped resource in this regard. He and his colleague Grzegorz Niedźwiedzki conducted a small pilot study years ago, and discovered an absolute cornucopia of well-preserved food remains. Since then, his interest has only deepened.
“We can never be sure about extinct animals’ diet and feeding behaviours if we do not look at bromalites,” he explained. “Sure, we can guess, but analyzing bromalites gives us direct evidence of what animals were eating. We found many surprises along the way that we would have never guessed from the record of fossil bones only.”
The new research involved studying a selection of various types of bromalite: coprolites (fossilized feces), regurgitalites (fossilized vomit), and cololites (fossilized feces that was still in the dinosaur’s intestine when it died). These samples were subjected to a number of analyses, including visual examination, synchrotron microtomography, and scanning electron microscopy.
The researchers examined more than 500 of these fossils from the Polish Basin region of Pangea from the late Triassic to the early Jurassic, from about 230 million to 200 million years ago. When you think about how many times dinosaurs would have pooped in a 30-million-year timeframe, 500 doesn’t seem like a lot, but the research nevertheless yielded comprehensive insights into the complexities of the period’s ecosystems.
“We were incredibly surprised by many of the findings! We found tiny insect remains in many coprolites, and in one coprolite the little beetles were found intact with the tiny legs and antennae still preserved,” Qvarnström said.
“In one site we found coprolites packed with pieces of bones and crushed teeth. Apparently, the early archosaur Smok, perhaps the first big theropod in the region, used its powerful bite to crush bones like a modern hyena. Unlike the hyena, though, the teeth of Smok were not very robust, but blade-like, which resulted in them repeatedly breaking and ending up in the coprolites.”
They also found that many carnivorous dinosaurs were eating other land animals, rather than fish or insects as had been thought. And the bromalites of herbivorous sauropod dinosaurs often contained remnants of burnt plants.
The researchers think that this might have aided a more adventurous diet, since charcoal can absorb toxins, thus neutralizing the potentially dangerous ferns the herbivores also ingested. And, in turn, this would have helped the dinosaurs thrive.
“The way these herbivores were sampling all plants in the new flora, in contrast to the non-dinosaur herbivores which had been more specialized, must have been an incredible advantage under changing environmental conditions,” Qvarnström told ScienceAlert.
This strategy cannot necessarily be extrapolated to the rest of the globe; the Polish Basin is just one region in one part of the world. But the work the team conducted could be repeated for other dinosaur habitats, which will, hopefully, reveal trends in the rise of the dinosaurs.
“There were so many exciting findings! All the fantastic coprolite inclusions and unusual diets were very cool to discover. The most fascinating thing for me was that we were able to use seemingly uninteresting and perhaps repulsive fossils and merge various data sources to get unprecedented insight into the ecology and feeding adaptations of early dinosaurs,” Qvarnström said.
“Now we have a good model to test and compare to other areas of the world. We are extremely interested in doing that, and this time we are also aware of how much time and effort it requires. But we are ready for it!”
Excelsior, friends. The poop awaits.
The research has been published in Nature.
