I know that the name Tyrannosaurus means "tyrant reptile", but I was curious to see if Barnum Brown was comparing the predatory nature of T. rex to the brutality of the ancient Greek tyrants like Hippias because the 20th century's most brutal tyrants rose to power decades after T. rex was described in 1905 (in a similar twist, at one time, one of the specimens of Tarbosaurus bataar was named Jenghizkhan by George Olshevsky because its predatory nature is comparable to the plunder and destruction that Genghis Khan and his hordes wreaked on the peoples of the territories they conquered).