sentences:  "Albertosaurus" and "Gorgosaurus" individuals both grow the most rapidly during a four-year period until they are approximately 16.The Dry Island bonebed discovered by Barnum Brown and his crew contains the remains of 26 "Albertosaurus", the most individuals found in one locality of any large Cretaceous theropod, and the second-most of any large theropod dinosaur behind the "Allosaurus" assemblage at the Cleveland-Lloyd Dinosaur Quarry in Utah.The group seems to be composed of one very old adult; eight adults between 17 and 23 years old; seven sub-adults undergoing their rapid growth phases at between 12 and 16 years old; and six juveniles between the ages of 2 and 11 years, who had not yet reached the growth phase.