For decades, paleontologists argued over the lone skull used to establish the distinct species Nanotyrannus. Was it truly a separate species or simply a juvenile Tyrannosaurus rex? A new paper published in Science has definitively shown that Nanotyrannus is, in fact, nearly fully grown and not an im mature T. rex, at the same time revealing new insights into how these giant predators achieved such terrifying sizes so quickly. ...read more read less