We finally know why there were very few medium-sized dinosaurs

T. Rex (Tyrannosaurus Rex) was a formidable predator from a young age, according to a new article in Science magazine. Published by an American research group, it is mentioned that the descendants of gigantic dinosaurs such as the tyrannosaurus, which grew from the size of a cat to giant monsters, restructured their ecosystems to better dominate their smaller competitors.

A study was conducted to answer a crucial question: Why were there so many more species large than small in the days of the dinosaurs? A different reality than today.

One of the largest carnivores in the world

According to Kat Schroeder, the University of New Mexico graduate student who led the study, “dinosaur communities like shopping malls were full of teenagers on Saturday afternoons.” In other words, teenagers were an important part of every species.

This situation had a significant impact on the resources available. In the case of tyrannosaurs, thanks to their imposing body, they would have managed to occupy the resources of other communities from an early age. In fact, it is one of the largest terrestrial carnivores that has ever existed. To test this hypothesis, Schröder and his team analyzed fossils from more than 500 species of dinosaurs that have lived in all four corners of the earth.

A population with no medium-sized species

To do this, the researchers classified the species according to their size and whether they were herbivores or carnivores. This enabled them to see a significant void within the communities that included mega theropods, particularly giant predators like T. rex.

A population with no medium-sized species. Photo credit: Shutterstock / AmeliAU

In fact, these groups were almost devoid of average-sized carnivorous dinosaurs. “In communities with mega theropods there are very few carnivorous dinosaurs between 100 and 1000 kilograms,” explained Kat Schroeder. It turns out that the teenagers in this group, which includes the Tyrannosaurus Rex, fill that void.

Teenage dinosaurs that looked more like adults

This finding is confirmed by the evolution of the dinosaur population over time. The Jurassic period (200 to 145 million years ago) had smaller holes in the carnivorous dinosaur category weighing between 100 and 1,000 kilograms, while the Cretaceous (between 145 and 65 million years ago) had very large ones.

The reason, the researchers say, is that the juvenile mega theropods of the Jurassic era looked more like adults. They had a variety of herbivores available to devour. “The Cretaceous period, on the other hand, is completely dominated by tyranosaurs and abelisaurs, which develop strongly as they grow,” explained Kat Schroeder.

Back to top button