Researchers are calculating how many T. rex species roamed the Earth

(CNN) – Dedicated to the arduous task of making calculations, a team of researchers reported that billions of Rex Dinosaurs, also known as T. rex, roamed North America during their remarkable reigns as great predators.

Paleontologists from the University of California, Berkeley, set out to determine how many Tyrannosaurus rex lived during the Cretaceous Period, about 65 to 98 million years ago. And they knew it would not be an easy task.

Clues from the fossils

Fossils have long been used to deepen what we know about extinct creatures such as dinosaurs. But experts say it can be difficult to use these leftovers to calculate population density and abundance.

“There is no information to make an account,” explained Charles Marshall, director of the Paleontology Museum at the University of California. Marshall was part of the investigation team. «If you find an Easter egg in your garden, how do you calculate the number of Easter eggs there? It simply cannot be done. The information is required from another party. For example, the density of Easter eggs, the area in which to find them and the number of years the Easter eggs have been laid in the gardens.

Previously, researchers tried to estimate things like the likely size of a tyrannosaurus range. Also your basic energy needs. So that’s a nice extension of the previous work. “It includes a lot of recent information about dinosaurs,” said Nizar Ibrahim, a paleontologist at the University of Portsmouth (UK) and a National Geographic explorer, who was not involved in the research.

We just have to keep in mind that all of these interesting studies come with a certain amount of uncertainty. “We still don’t know much about dinosaurs, including a Hollywood star like T-Rex,” Ibrahim added in an email.

There were 20,000 T-rex in North America at one time

By studying the fossil record, density data, and climate model data, the team at UC Berkeley estimated that there may have been about 20,000 adult Tyrannosaurus rex, which lived across North America and were present at any given time. This, the researchers explain a study published in magazine Science, Means that about 2.5 billion predators lived and died during the approximately 2.5 million years that the dinosaurs lived.

For the first time, the team also calculated the longevity of a dinosaur. Using the scientific literature and expert opinions, they estimated that the probable age of sexual maturity of T. rex was 15.5 years, and that it could be as long as 20 years. The average body mass of an adult dinosaur was around 5,200 kg, and growth in sexual maturity could lead to it reaching 7,000 kg.

From these calculations, the team concluded that each generation of T. rex lasted about 19 years, and that there was one dinosaur per 100 square kilometers.

A study can help to understand species change

The researchers also determined that with twenty thousand dinosaurs and around 127,000 generations of these species, there would be a total of 2.5 billion dinosaurs.

Jason C. Ball, head of fossil preparation at the Bighorn Basin Institute for Paleontology and artist, said the researchers’ methods “appear to be very helpful, while also showing the current limits of what can be done with what we know now.” That was not part of the study.

“I am sure it will open the doors to further address the issues of population density and what that means over time,” Paul added in an email. “So this could really help to understand things like change of species over time in relation to evolution and changing ecosystems,” he added.

The study authors estimate that the species’ population density is equivalent to 3,800 carnivorous dinosaurs in an area the size of California, but only two in an area the size of Washington City.

The T. Rex fossils are extraordinary

On the other hand, the results also allowed the report’s authors to determine that only the fossil remains of T. rex are preserved at 1 in 80 million.

The big impact of this study may be that it shows just how rare fossils are. Meaning it represents only a small fraction of the individual living things that were present, let alone the depth of time, as it happens within a few thousand to millions of years, “Paul said.

“In a way, this was a paleontology training to see how well we knew it and how to identify it,” said Marshall, a co-author of the study and professor of integrative biology and earth and planetary sciences at the University of California, Berkeley. In a statement.

“It’s amazing how much we really know about these dinosaurs, and from there, how much we can compute. Our knowledge of T. rex has expanded greatly in recent decades thanks to more fossils, more methods of analyzing it, and better ways to incorporate information about many known fossils. .

Beyond the T. Rex

Ibrahim also pointed out other possibilities derived from this study.

“There are a lot of things that we don’t know about dinosaur physiology, behavior and feeding environment, but this study provides an interesting approach to estimate the abundance and rate of maintenance of dinosaurs,” he said.

I’d like to see it apply to other dinosaurs known from their abundant fossils. Looking at a broader group of dinosaurs – predators and prey – might allow us to better compare animal societies in the dinosaur era with modern societies.

“But we are only looking at the surface, and even with this exciting study, there is still a long way to go before we can confidently apply such methods on a larger scale to study dinosaurs,” he added.

CNN’s Kristen Rogers contributed to this report.