Paleontologists from the University of New Mexico and the University of Nebraska-Lincoln have shown that the offspring of massive carnivorous dinosaurs, such as Tyrannosaurus rex, may have fundamentally reshaped their communities by competing with rival smaller species.
The study, which was published this week in the journal Science, Is the first to examine the diversity of dinosaurs at a community level while treating juveniles as their own environmental entity.
“The dinosaur communities were like shopping malls on Saturday afternoons – they were full of teenagers,” Kat Schroeder explained, graduate In the UNM Biology department who led the study. “They formed a large portion of individuals in a species and could have had a very real impact on the resources available in the communities.”
Because they were born from white, Dinosaurs Like the T. rex a little boy – roughly the size of a domestic cat. This means that, as they grow to the size of a city bus, these “gigantic legs”, weighing between one and eight tons, would have altered hunting patterns and prey elements. Paleontologists have long suspected that giant carnivorous dinosaurs would change their behavior as they grow. But how this affected the world around them remained largely unknown.
“We wanted to test the idea that dinosaurs might assume the role of multiple species as they grow, which limits the number of actual species that can coexist in a community,” Schroeder said.
The number of different species of dinosaurs known from all over the world is low, especially among small species.
“Dinosaurs had surprisingly low diversity. Even considering fossilization biases, there weren’t that many dinosaur species,” said Felisa Smith, a professor of biology at UNM and a consultant to Schroeder alumni.
To deal with the issue of declining dinosaur diversity, Schroeder and her colleagues collected data from well-known fossil sites from around the world, including more than 550 dinosaur species. They organized dinosaurs by mass and diet, and they examined the number of small, medium, and large dinosaurs in each community.
They found a strikingly clear pattern:
“ There is a gap – very few carnivorous dinosaurs between 100-1000kg [200 pounds to one ton] “They are found in societies that contain giant legs,” Schroeder said. “And the young of those gigantic legs fit in this space.”
Schroeder also notes that looking at the diversity of dinosaurs over time was fundamental. Jurassic societies (200-145 million years ago) had smaller vacuoles and Cretaceous societies (145-65 million years ago) had large vacuoles.
“Giant legs in the Jurassic period don’t change much,” Schroeder said. “Adolescents are like adults, leaving more space in society for many large families than huge legs as well as some small carnivores.” “The Cretaceous, on the other hand, is dominated by Tyrannosaurs and Apelisaurs, which change a lot as they grow.”
To see if the gap was really caused by gigantic events, Schroeder and her colleagues rebuilt communities with teens in mind. By combining Growth rates From the subspecies found in cross-sections of the bones, and the number of small dinosaurs that survive each year based on the mass death fossil populations, the team calculated the proportion of the massive species of legs that could be juveniles.
Schroeder explained that this research is important because (at least in part) it explains why dinosaur diversity is lower than expected based on other fossil groups. It also explains why there are many more Class Dinosaurs are more than small, which is the opposite of what is expected. Most importantly, she added, it illustrates growth outcomes from very young children to very large adults in an ecosystem.
“Dinosaurs have been a lifelong passion. I was and still am a“ kid of dinosaurs. ”My interest in dinosaur diversity came when I realized that no one was looking at dinosaurs the way we look at modern mammals and birds, Schroeder said. “There is a lot to be gained from applying modern environmental and ancient ecological methods to dinosaurs. Fortunately, we are now in an era of dinosaur research where a lot of information is available digitally, so data-intensive environmental questions are now making more sense for dinosaur paleontology.”
K. Schroeder Al Al, “The Impact of Juvenile Dinosaurs on Society Structure and Diversity” Science (2021). science.sciencemag.org/cgi/doi… 1126 / science.abd9220
University of New Mexico
the quote: Are Teenage “Despots” Outnumbering Other Dinosaurs? (2021, Feb 25) Retrieved February 25, 2022, from https://phys.org/news/2021-02-teenage-tyrants-outcompete-dinosaurs.html
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