Tyrannosaurids are theropod dinosaurs from the Cretaceous period. This family of dinosaurs includes the infamous Tyrannosaurus rex. Tyrannosaurids were powerful and deadly animals, with certain genera being able to crush bone with a single bite.
Nigel Marven encountered a pack of Tyrannosaurus rex whilst on a rescue mission to rescue them from extinction. In the end, he managed to bring back two juvenile siblings who were later called Terrence and Matilda. (PP: T-Rex Returns)
Whilst on an expedition to late Cretaceous Texas, Nigel encountered Albertosaurus, an early cousin to Tyrannosaurus rex. A pair of them chased Nigel and later, three Albertosaurus tried to defend their kill from a congregation of Deinosuchus but failed. (PP: Supercroc)