Nav: Home

Discriminating diets of meat-eating dinosaurs

November 03, 2019

A big problem with dinosaurs is that there seem to be too many meat-eaters. From studies of modern animals, there is a feeding pyramid, with plants at the bottom, then plant-eaters, and then meat-eaters at the top.

A new study by scientists at the University of Bristol's School of Earth Sciences, published in the journal Palaeontology, shows that dinosaurian meat-eaters, the theropod dinosaurs, specialised a great deal, and so broadened their food base.

The big ones, such as Allosaurus and Tyrannosaurs Rex, fed on other dinosaurs. But there were also lots of small meat-eaters that probably fed on other animals such as lizards and mammals. And some of the theropods even became plant-eaters.

Joep Schaeffer carried out the study as part of his studies for the MSc in Palaeobiology at Bristol. He said: "I was always mad about tyrannosaurs and other meat-eating dinosaurs, but this study tested my computing ability.

"I measured everything I could from the jaws and teeth of 83 theropod dinosaurs, including the giants, but also small ones the size of a turkey."

Professor Emily Rayfield, who co-led the research, added: "Our idea was to describe every possible jaw shape and tooth shape in terms of about 80 measurements.

"Were all these meat-eaters feeding in the same way on the same things? If so, that would mean a lot of competition."

Professor Mike Benton, who also co-led the research, said: "We also had problems in deciding which computational method to use.

"We could simply treat all the separate measurements as part of the mix, or we could measure so-called landmarks, where we make an outline of the jaw and tooth shape by marking dots round the edge.

So, in the end, Joep ran his analyses using each possible measurement method, and we compared the results."

Dr Tom Stubbs, who also worked on the study, added: "These kinds of studies are very informative. We have a huge amount of data from many excellent specimens, but there are many different ways of analyzing the data.

"We were able to show that it didn't matter which was used to do the calculations, we found the same results - tyrannosaurs were different from all the other theropods, and there were big differences between the theropods."

The analyses separated out three groups - the large dinosaur-eaters, the small carnivores and the herbivores. In particular, the tyrannosaurs such as T. rex were quite distinct - they had deeper jaws and more powerful teeth than any of the other theropods, and so had evidently evolved particular ways of dealing with large prey.

The other key finding is that the maniraptoriform 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 greatest range of functions.

Joep Schaffer added: "Tyrannosaurs were good at subduing large prey with their massive jaws. So, they all had the same kinds of jaws and teeth. But the maniraptoriforms were experimenting with a wide range of smaller prey, maybe from small dinosaurs to early mammals and lizards... even some large, juicy insects.

"This meant they had evolved a much wider array of kinds of jaws and teeth, and while many probably continued to hunt prey on the ground, others might have become specialized to hunting in the trees and pursuing fast-moving prey."
-end-


University of Bristol

Related Dinosaurs Articles:

Some dinosaurs could fly before they were birds
New research using the most comprehensive study of feathered dinosaurs and early birds has revised the evolutionary relationships of dinosaurs at the origin of birds.
Tracking Australia's gigantic carnivorous dinosaurs
North America had the T. rex, South America had the Giganotosaurus and Africa the Spinosaurus - now evidence shows Australia had gigantic predatory dinosaurs.
Ancient crocodiles walked on two legs like dinosaurs
An international research team has been stunned to discover that some species of ancient crocodiles walked on their two hind legs like dinosaurs and measured over three metres in length.
Finding a genus home for Alaska's dinosaurs
A re-analysis of dinosaur skulls from northern Alaska suggests they belong to a genus Edmontosaurus, and not to the genus recently proposed by scientists in 2015.
Can we really tell male and female dinosaurs apart?
Scientists worldwide have long debated our ability to identify male and female dinosaurs.
In death of dinosaurs, it was all about the asteroid -- not volcanoes
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers.
Discriminating diets of meat-eating dinosaurs
A big problem with dinosaurs is that there seem to be too many meat-eaters.
Jurassic dinosaurs trotted between Africa and Europe
Dinosaur footprints found in several European countries, very similar to others in Morocco, suggest that they could have been dispersed between the two continents by land masses separated by a shallow sea more than 145 million years ago.
In the shadow of the dinosaurs
Research published this Wednesday in Scientific Reports describes Clevosaurus hadroprodon, a new reptile species from Rio Grande do Sul state in southern Brazil.
When the dinosaurs died, lichens thrived
When the asteroid hit, dinosaurs weren't the only ones that suffered.
More Dinosaurs News and Dinosaurs Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.