A recent study suggests that some dinosaurs were particular about their diets, challenging previously held beliefs about how these ancient creatures consumed food. Specifically, the research indicates that herbivorous dinosaurs had preferences for certain plant parts, with their diets potentially driven more by the nutritional value and texture of food rather than their size. An analysis of calcium isotopes in the fossilized enamel of dinosaur teeth provides insight into these preferences. Paleontologist Liam Norris emphasizes that softer plant parts like leaves were likely preferred over tougher materials like twigs or bark, indicating a level of dietary selectivity in these animals.
Norris and his team analyzed calcium isotope levels in dinosaur teeth and compared these with modern herbivores. Their findings revealed surprising dietary choices among some well-known dinosaurs, most notably the sauropod Camarasaurus. Historically thought to have primarily grazed on treetops, the study suggests that Camarasaurus actually consumed more woody plants and twigs than initially expected. In contrast, smaller dinosaurs like Camptosaurus opted for softer parts such as leaves and buds. This observation contradicts the long-standing assumption that larger dinosaurs would necessarily have access to the most desirable food sources.
The implications of these findings are significant for understanding dinosaur diets. Paul Barrett, a dinosaur expert not involved in the study, asserts that using calcium isotopes to analyze dietary habits is an innovative approach that adds depth to the existing body of research. He highlights that this methodology may be particularly useful in deciphering diets when fossil evidence is ambiguous. The team’s work may ultimately help clarify the dietary landscape of these ancient creatures, shifting the focus from size to specific dietary adaptations.
Moreover, Norris’s group extended their investigations to carnivorous dinosaurs, examining the calcium isotope levels in teeth from species such as Eutretauranosuchus and Allosaurus. The results indicated that Eutretauranosuchus primarily fed on fish, while Allosaurus was a predator of other dinosaurs, albeit with less emphasis on bones compared to its later relative, Tyrannosaurus rex. This study’s findings enrich the narrative about the dietary diversity of dinosaurs, revealing complex feeding behaviors across different species.
The researchers collected samples from the Carnegie Quarry in Utah, a notable fossil-rich site containing Late Jurassic dinosaur remains. They utilized both previously classified teeth and samples taken directly from the quarry wall, providing a wide range of data about the dinosaurs that once inhabited the area. This meticulous sampling differs from earlier studies that used broader formations, marking this research as the first focused specifically on the Carnegie Quarry site.
Expert Michael Benton noted the innovative nature of this research, particularly highlighting the use of calcium isotopes on such ancient dinosaur teeth. Barrett emphasized that the study validates the application of this chemical analysis in paleontology, confirming that the dietary signatures can persist in tooth enamel over millions of years. This new research opens avenues for further exploration of dietary habits in ancient animals and holds potential for uncovering more about their ecological dynamics.
