Tyrannosaurus rex
From Memory Alpha, the free Star Trek reference.
Tyrannosaurus rex was an Earth dinosaur that lived in the Cretaceous period.
Doctor Noonien Soong was very fond of dinosaurs and kept a Tyrannosaurus skull and some small models of the dinosaur in his laboratory on Terlina III. (TNG: "Brothers")
After Jonathan Archer restored a damaged timeline, a Tyrannosaurus rex could be seen in the timestream as the timeline realigned itself. (ENT: "Storm Front, Part II")
