Nanotyrannus (name meaning "Dwarf Tyrant") is a controversial genus of tyrannosaurid dinosaur. It has long been argued that Nanotyrannus is nothing more than a juvenile of Tyrannosaurus or a similar genus.
In the Series 2 finale, "Death of a Dynasty II: The Return of the King", a pack of Nanotyrannus were brought to the park from prehistoric Montana 65 million years ago. They reside in the Tyrannosaur Kingdom Enclosure.