Jan. 5 () –
Although most early dinosaurs were vegetarians, there were striking differences in the way these animals tackled a plant-based diet.
Scientists from the Natural History Museum and the Universities of Bristol and Birmingham used CT scans of dinosaur skulls to trace the evolution of early plant-eating dinosaurs, reconstructing jaw muscles and measuring the animals’ bite force. to understand how dinosaur diets evolved.
Five skulls from the Ornithischia herbivorous group provided the key to unlocking their eating habits: Heterodontosaurus, Lesothosaurus, Scelidosaurus, Hypsilophodon, and Psittacosaurus, the earliest representatives of what would become the major groups of herbivorous dinosaurs.
Later ornithischian dinosaurs, such as Triceratops and Stegosaurus, display a wide range of adaptations for eating plants, but his first relatives had not been properly examined until now.
By publishing their findings in the journal Current Biology, scientists reveal that early “vegetarian” dinosaurs had evolved very different ways of approaching a plant diet.
Heterodontosaurus appears to have had large jaw muscles relative to the size of its skull, producing a large bite force, ideal for consuming tough vegetation. Scelidosaurus had a similar bite force, but relatively smaller jaw muscles compared to its skull. However, these animals had a larger overall body size and could achieve a strong bite. In contrast, the Hypsilophodon skull did not have large muscles. Instead, these dinosaurs refocused their muscles to bite more efficiently but with less muscle force.
Dr. Stephan Lautenschlager, from the University of Birmingham, said it’s a statement: “We found that each dinosaur addressed the problems posed by a plant-based diet by adopting very different feeding techniques. Some compensated for poor food performance through their large size, while others developed larger jaw muscles, increased jaw efficiency, jaw system or these combined approaches.Although these animals looked very similar, their individual solutions to the same problems illustrate the unpredictable nature of evolution“.
Contrary to popular belief, most dinosaurs were herbivorous, though all descended from carnivorous ancestors. Much is already known about how different dinosaurs ate their food, but relatively little is known about how their preferred feeding styles evolved.
After the CT scans of the skulls, the team reconstructed the jaw muscles using data from birds and crocodiles to help indicate where the muscles would have been. They then carried out “finite element analysis,” which involves dividing the skull into thousands of individual parts (called elements). The bite force that these muscles can generate is calculated based on their size and arrangement.
Each skull was then simulated to bite into an imaginary object to see how the different elements respond to the applied force. These models generate heat maps showing which areas of the skull are highly stressed and which are not. The results revealed that, Although all of these dinosaurs ate plants, they each had different ways of doing so.
