 Speculation on the pack @-@ hunting habits of Albertosaurus were made by a few researchers who suggest that the younger members of the pack may have been responsible for driving their prey towards the adults , who were larger and more powerful , but also slower . Juveniles may also have had different lifestyles than adults , filling predator niches between those of the enormous adults and the smaller contemporaneous theropods , the largest of which were two orders of magnitude smaller than an adult Albertosaurus in mass . However , as the preservation of behavior in the fossil record is exceedingly rare , these ideas cannot readily be tested . Phil Currie speculates that the Daspletosaurus formed packs to hunt , although this cannot be stated with certainty . There is no evidence of such gregarious behavior in Gorgosaurus . 
