Jurassic Park may have the tourists, but Triassic Toilet serves up the science. The inner lives of dinosaurs are revealed in Digestive contents and food webs record the advent of dinosaur supremacy, a study by Martin Qvarnström and others published in the journal Nature. The fossilized remains of their excrement tells the story of how these creatures came to rule the planetary ecosystem in just a few million years.
By studying the shape and contents of the bromalitesand linking them to fossilized skeletons and footprintsfound at the sites, researchers were able to identifyand categorize the animals that likely produced them.
Doing so allowed the researchers to understand how many and what type and size of dinosaurs, as well as other vertebrate animals, were in the landscape at a given point in time. The analysis, which took 10 years to complete, allowed the team to piece together why dinosaurs came to prominence.
The short of it is that dinos were extremely flexible about what they ate, allowing them to adapt well to different sources of energy. From the paper's abstract:
Here we use hundreds of fossils with direct evidence of feeding to compare trophic dynamics across five vertebrate assemblages that record this event in the Triassic–Jurassic succession of the Polish Basin (central Europe). Bromalites, fossil digestive products, increase in size and diversity across the interval, indicating the emergence of larger dinosaur faunas with new feeding patterns. Well-preserved food residues and bromalite-taxon associations enable broad inferences of trophic interactions. Our results, integrated with climate and plant data, indicate a stepwise increase of dinosaur diversity and ecospace occupancy in the area. This involved (1) a replacement of non-dinosaur guild members by opportunistic and omnivorous dinosaur precursors, followed by (2) the emergence of insect and fish-eating theropods and small omnivorous dinosaurs.
Climate change in the latest Triassic5,6,7 resulted in substantial vegetation changes that paved the way for ((3) and (4)) an expansion of herbivore ecospace and the replacement of pseudosuchian and therapsid herbivores by large sauropodomorphs and early ornithischians that ingested food of a broader range, even including burnt plants. Finally, (5) theropods rapidly evolved and developed enormous sizes in response to the appearance of the new herbivore guild. We suggest that the processes shown by the Polish data may explain global patterns, shedding new light on the environmentally governed emergence of dinosaur dominance and gigantism that endured until the end-Cretaceous mass extinction.
The essential "previously" to this post is With how much force did brachiosauruses vomit?
