The time difference between when Stegosaurus and Tyrannosaurus lived is greater than the time difference between Tyrannosaurus and now.
Stegosaurus lived between 155 and 150 million years ago and Tyrannosaurus lived between 68 to 66 million years ago.
Stegosaurus means roof and sauros also called lizard, is a genus of herbivorous thyreophoran dinosaur. Fossils of this genus date to the Late Jurassic period, where they are found in Kimmeridgian to early Tithonian aged strata, between 155 and 150 million years ago, in the western United States and Portugal.
The name Stegosaurus means “covered lizard”, in reference to its bony plates.
Of the species that have been classified in the upper Morrison Formation of the western US, only three are universally recognized; S. stenops, S. ungulatus and S. sulcatus.
The remains of over 80 individual animals of this genus have been found. Stegosaurus would have lived alongside dinosaurs such as Apatosaurus, Diplodocus, Brachiosaurus, Allosaurus, and Ceratosaurus; the latter two may have been predators of it.
Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex, often colloquially called simply T. rex or T-Rex, is one of the most well-represented of the large theropods.
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.
It was the last known member of the tyrannosaurids, and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.
More than 50 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens.
The abundance of fossil material has allowed significant research into many aspects of its biology, including its life history and biomechanics.