In a study published in Science Advances on Wednesday, researchers reveal a stunningly detailed analysis on cross-sections of bone from juvenile tyrannosaurs. The results suggest that T. rex’s growth rates varied as it aged, and that these predatory dinosaurs could seemingly slow their growth when food was scarce, potentially giving them an evolutionary leg up. (Also find out about “Scotty,” the biggest T. rex discovered to date.)
The research also casts further doubt on the existence of Nanotyrannus, a controversial “pygmy” tyrannosaur proposed to have lived alongside T. rex. In the 1980s, paleontologists examining a set of small, slender carnivores concluded that the Cretaceous fossils belonged to their own distinct tyrannosaur species. However, subsequent studies have led most experts to agree that the fossils assigned to Nanotyrannus are probably juvenile T. rex.
Read more here: NationalGeographic