It has been years since the debate started on the existence of the dwarf species of the Tyrannosaurus rex dinosaur. Finally, after three decades a new study suggested that the species probably did not exist at all.
It should be mentioned that T-Rex is one of the most famous ancient species who were a type of theropod dinosaur. Over the years, scientists studied the T-Rex fossils to understand how big it was, how it hunted and how it lived.
Palaeontologist Robert Bakker along with his colleagues at the Cleveland (Ohio) Museum of Natural History named a specimen first discovered in 1942 to Nanotyrannus. Later, in 2001, a separate team found almost a complete skeleton of a small Tyrannosaurus near the town of Ekalaka in Montana which was named as Jane and soon classified it as a juvenile Tyrannosaurus rex.
However, other researchers mentioned that Jane was part of the newly classified Nanotyrannus species and stated that the skulls, as well as bones, were different from the T-rex adults.
A new study on dwarf T-rex
A study, which was published in the journal Science Advances, led by Holly Woodward of Oklahoma State University revealed that the researchers analyzed samples from the interior of Jane's tibia and femur bones as well as from a less complete set of bones from an animal dubbed Petey. After this process, they came to know that the two were immature individuals, not adults.
The study author mentioned that the existence of the Nanotyrannus seems very unlikely. In addition, Woodward told AFP that "The really cool thing about fossil bones is that a whole bone fossilizes even down to the microscopic size. We can infer the growth rate, age (and) maturity level."
Analyzing fossil evidence
To carry out this study, researchers analyzed extremely thin slices from the bone samples from which light can pass through. After studying it under the powerful microscopes the size of the blood vessel openings revealed that when these two dinosaurs died they were still in a phase of rapid growth.
The researchers also able to count the growth rings in each of their bones and found that while Jane was 13, for Petey the age is 15. As per Woodward, "Everyone loves T-rex, but we don't really know much about how it grew up. It's probably the most famous dinosaur in the world, and we mostly just have really large skeletons of it."
He also mentioned that almost five to seven fossils of young T-rex dinosaurs are known to exist in the world, while some of those remains are in private collections not accessible to researchers.