known individual ( LACM  28471, the "Jordan theropod") is estimated to have weighed only 30 kg (66 lb), while the largest, such as  FMNH  PR2081 (" Sue ") most likely weighed over 5,400 kg (12,000 lb).  Histologic  analysis of  Tyrannosaurus rex  bones showed LACM 28471 had aged only 2 years when it died,