At its peak, 66 million years ago, Tyrannosaurus rex was one of the fiercest creatures on Earth. A specimen discovered almost 30 years ago reveals that animals have grown even more than fossils have suggested.
Scientists estimate that the giant dinosaur weighed nearly 10 tons and was about 30 years old. His age is probably what has allowed him to become so big, say the researchers. Tyrannosaurs continued to grow throughout their lives.
"Tyrannosaurs seem to be an animal that grew up very quickly but did not survive very long into adulthood," said Scott Persons, paleontologist at the University of Alberta at the University of Alberta. Canada, who led the new research. "In fact, many individuals have probably not reached adult size."
The researchers first stumbled upon the skeleton of the big T. rex in 1991. The fossil, affectionately nicknamed "Scotty" for the scotch bottle opened to celebrate its discovery, was discovered near Eastend, Saskatchewan, a town in the southwestern part of the province, located about 35 km north of the Montana border. Scientists began digging the dinosaur in 1994 and presented their findings Friday in the newspaper The anatomical file.
Digging the bones of the colossal T. rex was "a huge company," said people. The bones were enclosed in a very hard cemented sandstone rich in iron, making the fossils difficult to extract. In addition, scientists could only work on excavations in summer, when the soil is not frozen. Thus, Scotty was collected in some parts of the excavation site and brought back to the laboratory for examination during the rest of the year. "It's not an excavation," said Persons. "It's a 30-year mortgage."
It was only when Scotty was completely unearthed and fully assembled that the researchers were able to complete their investigation. The analysis of the dinosaur's bones for 25 years revealed that Scotty led a violent life. the T. rex had an infected jaw, an included tooth, and broken ribs that healed before death. The damage to the vertebrae of Scotty's tail suggest another T. rex bitten at some point.
However, the bones also revealed that Scotty was an important and long-lived survivor. When the researchers measured Scotty's bones, they discovered that the dinosaur was about 42 feet long and weighed nearly 20,000 pounds. When the team analyzed the bone growth model, which recorded annual growth similar to that of annual growth rings of a tree trunk, Scotty was about 30 years old, making it the longer living T. rex known.
The lack of other similar sizes T. rex the fossils suggest that most other dinosaurs have not lived long enough to reach their full growth potential.
"Scotty has pushed the size limits we know now T. rex was, "said people.
Dinosaur fossils also tell paleontologists that "all the other dinosaurs we know have probably a much larger size range than we currently know. As we discover more, we will end up with larger individuals, "added Persons