The big problem with dinosaurs is that there seems to be too much meat to eat. From studies of modern animals there is a feeding pyramid, with plants at the bottom, then plant-eating1, and then carnivorous at the top.
A new study by scientists at the Bristol School of Earth Sciences published in the journal Palaeontology, shows that dinosaur carnivores, dinosaur theropods have specialized much and thus expanded their nutritional base.
Large, such as Allosaurus and Tyrannosaurus rex fed on other dinosaurs. But there were also many small carnivores that probably ate other animals such as lizards and mammals. And some of theropods even become food plants.
Joop Schaefer conducts the study as part of his studies for a Bachelor of Palaeobiology in Bristol. He says: "I was always angry about tyrannosaurs and other dinosaurs eating meat, but this study tested my computer skills. I measured everything I could from the jaws and teeth of 83 theropod dinosaurs, including giants, but also small, the size of a turkey. ”
Professor Emily Rayfield, who led the study, added: "Our idea was to describe every possible jaw and tooth shape with respect to about 80 measurements. Did all these meat eaters eat the same things in the same way? If so, it would mean great competition.
Professor Mike Benton, who also directs the study, said: "We had problems deciding which computing method to use. We can simply treat all the individual measurements as part of the mixture, or measure the so-called landmarks where we draw the shape of the jaw and tooth, marking points along the edge. Finally, Jope performed his analysis using every possible measurement method, and we compared the results. ”
Dr. Tom Stubbs, who also worked on the study, added: "These types of studies are very informative. We have a huge amount of data from many excellent samples, but there are many different ways to analyze the data. We were able to show that no matter who was used for the calculations, we found the same results – the tyrannosaurs were different from all other theropods and there were large differences between theropods. "
Analyzes divided into three groups – large dinosaurs, small carnivores and herbivores. In particular, tyrannosaurs such as T. rex were quite distinct – they had deeper jaws and more powerful teeth than any of the other theropods, and thus clearly developed specific ways to deal with large prey.
Another key finding is that mannaptorformed theropods – those most closely related to birds – show the greatest amount of variation in jaw shapes. This suggests but does not prove that they had the largest range of features.
Joop Schaffer adds: "The Tyrannosaurus were good at conquering large prey with their massive jaws. So, they all had the same types of jaws and teeth. But maniraptoriforms experiment with a wide range of smaller prey, perhaps from small dinosaurs to early mammals and lizards … even some large, juicy insects.
"This means that they have developed a much wider range of jaws and teeth, and while many are likely to continue to prey on the ground, others may have specialized in hunting trees and pursuing high-speed prey. . "
Reference:" Morphological mismatch in the jaws of theropods: comparison of discrete signs and geometric morphometry "by Joep Schaeffer, Michael J. Benton, Emily J. Rayfield and Thomas L. Stubbs, November 3, 2019, Paleeontology .
doi: 10.1111 / pala.12455