Researchers in Argentina have discovered an Early Jurassic dinosaur whose stomach contains remains of its last meal, preserved for approximately 180 million years.
The fossils, discovered in marine–deltaic deposits of the Los Molles Formation, belong to a previously unknown dinosaur species in the order Ornithischia now named Isaberrysaura mollensis. The remains include a nearly complete skull, much of the body skeleton and partially intact stomach contents.
Analysis of the stomach contents indicates that these animals swallowed food without chewing and probably played an important role in seed dispersal in ancient Patagonia.
“For almost 180 million years, dinosaurs occurred in most ecosystems on Earth, interacting with their environment and other organisms, including plants,” explain the authors of a study published in Scientific Reports. “As in living ecosystems, complex relationships existed between plants and herbivores. However, little evidence reveals which plants, or which parts of them, dinosaurs consumed.”
The largest fossil seeds retained their complete fleshy outer covering, suggesting that they had been swallowed without chewing. The authors note that this is consistent with the tooth morphology of Isaberrysaura mollensis, which consumed cycad seeds without grinding them. Cycads are gymnosperms with a palm-like appearance.
The researchers explain that cycad stems, leaves and seeds contain toxic compounds, but the dinosaurs’ intestinal microorganisms may have produced enzymes capable of breaking them down. After ingestion and processing in the stomach, the hardest seeds were regurgitated, potentially explaining these dinosaurs’ role in seed dispersal.
Sources: phys.org
