what time period did the t rex live in
Maastrichtian age of the upper Cretaceous period, 68 to 66 million years ago
Tyrannosaurus
Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous period, 68 to 66 million years ago.
wiki:19588870
Tyrannosaurus [SEP] Introduction
The feeding habits, physiology and potential speed of "Tyrannosaurus rex" are a few subjects of debate. Its taxonomy is also controversial, as some scientists consider "Tarbosaurus bataar" from Asia to be a second "Tyrannosaurus" species while others maintain "Tarbosaurus" is a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with "Tyrannosaurus".