 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 that 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 . Other tyrannosaurids , including Albertosaurus , have been found in aggregations that some have suggested to represent mixed @-@ age packs , but there is no evidence of gregarious behavior in Gorgosaurus . 
