sentences:  "Gorgosaurus" spent as much as half its life in the juvenile phase before ballooning up to near-maximum size in only a few years.This, along with the complete lack of predators intermediate in size between huge adult tyrannosaurids and other small theropods, suggests these niches may have been filled by juvenile tyrannosaurids.This pattern is seen in modern Komodo dragons, whose hatchlings start off as tree-dwelling insectivores and slowly mature into massive apex predators capable of taking down large vertebrates.