Scientists have wondered for ages how many iconic extinct predators have populated the earth. Professor Charles Marshall is one of those hardworking researchers who hope to answer that. To this end, the scientist and his colleagues at the University of California at Berkeley focused their study on the western part of the United States, where states such as Montana and Wyoming have enabled the discovery of large numbers of tyrannosaur fossils.
A method that can be used on all extinct species
In their report, presented a few days ago in the online journal Science, the researchers claim to have developed a method that can be applied to all extinct species thanks to the relevance of the approach implemented.
Initially, the group focused on estimating the number of tyrannosaurs that roamed the earth throughout the Upper Cretaceous. As a reminder, this species of dinosaur lived in the upper part of Maastricht, the last stage of the Cretaceous system, around 68 to 66 million years ago in what is now North America.
A mass of up to 7 tons
To achieve their purpose, Marshall and his students used existing data to estimate the tyrannosaurus’ age of maturity. According to their calculations, it was 15.5 years old and the animal then had an average ecological body mass of 5.2 tons.
Tokyo, Japan – February 15, 2020, Tyrannosaurus Rex (T rex) skeletal fossil in the Tokyo Museum of Nature and Science, Tyrannosaurus is a large carnivorous dinosaur that lived in the Late Cretaceous Period. Photo credit: Shutterstock / AKKHARAT JARUSILAWONG
However, some large specimens weighed up to 7 tons. In addition, the team found that each individual had an average life expectancy of 19 years and lived in an average population density of about one dinosaur per 100 square kilometers.
2.5 billion people
By estimating the geographic distribution of tyrannosaur populations, taking into account the size of their territory (2.3 million square kilometers) and the number of generations that have lived there for about two million years (approximately 127,000), scientists have succeeded in determining the total number of Individuals: about 2.5 billion.
“It was exciting to use our extraordinary knowledge of tyrannosaurs to get that number,” said Marshall, quoted by SYFY. “The most important step was to assess correspondence with living species in terms of body weight and the number of people that can be supported per square kilometer. “”