Dinosaurs That Lived During the Cretaceous Period

Carnivorous Dinosaurs of the Cretaceous

• Some of the most famous of the carnivorous dinosaurs hail from the Cretaceous period. Carnotaurus, for example, was a dinosaur with bull-like horns protruding from its head. Smaller dinosaurs, like the velociraptor family, also flourished during this time. The most well-known Cretaceous carnivore, however, is on the completely opposite end of the size scale: Tyrannosaurus rex, a large, fearsome predator long a staple of popular culture, was one of the last dinosaurs, dying out with the rest after the asteroid impact and subsequent climate change that ended the Cretaceous.

Herbivorous Dinosaurs of the Cretaceous

• Notable plant-eating dinosaurs include the iguanodons and their later cousins, the hadrosaurs. The latter were distinctive, duck-billed dinosaurs, many of which had prominent crests like a Steller's Jay --- but made of bone. Ankylosaurus also lived in the Cretaceous. An "armored" dinosaur, it's notable for the bony plates that covered its body for protection. Ankylosaurus' tail ended in a heavy club made of bone. Scientists speculate it was used for defense --- it could be swung hard enough to break the bones of an attacker. Ceratopsian dinosaurs were Cretaceous herbivores distinguished by their horns and frill --- a thick flat plate of bone that extended behind their heads that may have been used to regulate body temperature or in courtship displays. The genus includes centrosaurus and the more famous triceratops.

Flying Dinosaurs

• At the dawn of the Cretaceous period, the skies were dominated by pterosaurs --- flying reptiles somewhat similar in appearance to dinosaurs but largely unrelated. As the period progressed, however, smaller pterosaurs found themselves outmatched by flying dinosaurs like those of the confuciusornis genus. By the end of the period, only massive pterosaurs like pteranodon continued to be competitive. Flying dinosaurs known as birds now ruled the roost --- they would also be the only dinosaurs to survive the K-T extinction event, remaining prominent to the present day.

The End

• Although the catastrophic extinction that ended the Cretaceous period was dramatic, dinosaurs were already facing a changing world. In the tens of millions of years before the K-T boundary, mammals had begun to diversify. As birds did to the pterosaurs, mammals began to dominate dinosaurs in the ecological roles served by smaller animals. In the dark, cold, hungry years following the asteroid impact at the end of the Cretaceous, these huge animals just couldn't compete. The impact event was the final nail in the coffin, an ecological shock that these massive reptiles were simply unable to recover from.