 Other tyrannosaurids exhibit extremely similar growth curves , although with lower growth rates corresponding to their lower adult sizes . Compared to albertosaurines , Daspletosaurus showed a faster growth rate during the rapid growth period due to its higher adult weight . The maximum growth rate in Daspletosaurus was 180 kilograms ( 400 lb ) per year , based on a mass estimate of 1 @,@ 800 kg ( 4 @,@ 000 lb ) in adults . Other authors have suggested higher adult weights for Daspletosaurus ; this would change the magnitude of the growth rate but not the overall pattern . The youngest known Albertosaurus is a two @-@ year @-@ old discovered in the Dry Island bonebed , which would have weighed about 50 kg ( 110 lb ) and measured slightly more than 2 metres ( 6 ft 7 in ) in length . The 10 @-@ metre ( 33 ft ) specimen from the same quarry is the oldest and largest known , at 28 years of age . The fastest growth rate is estimated to be around 12 – 16 years , reaching 122 kilograms ( 269 lb ) per year , based on an adult 1 @,@ 300 kilograms ( 2 @,@ 900 lb ) which is about five times slower than for <unk> For Gorgosaurus the calculated maximum growth rate is about 110 kilograms ( 240 lb ) during the rapid growth phase , which is comparable to that of Albertosaurus . 
