IMPORTANT CRETACEOUS DINOSAURS

What were the major dinosaurs during the Cretaceous period?

During the Early Cretaceous period, many of the Jurassic period dinosaurs disappeared. They were replaced by new, more diverse forms. Toward the end of the Cretaceous, the diversity of dinosaurs dropped dramatically. Of the saurischian sauropods, only the titanosaurids (Late Jurassic or Early Cretaceous period) remained as a major group and these herbivores were mostly found on the landmasses of Gondwana until the end of the Cretaceous period. In fact, through fossil evidence, it is thought that the titanosaurids replaced other sauropods, like the diplodocids and brachiosaurids, both of which died out around the Late Jurassic to Middle Cretaceous periods. Many of the saurischian theropods also became extinct during the Cretaceous period, while others diversified into a wide range of animals, from large carnivores like Tyrannosaurus, to speedy, agile predators like Velociraptor.

The ornithischian dinosaurs were the most numerous and diverse of all the dinosaurs in the Cretaceous period. They included the ornithopods, such as the Iguanodon, and the duck-billed dinosaurs, like the Edmontosaurus and Maiasaura; the armored ankylosaurs, including the Ankylosaurus, with its protective plating and tail-club; the thick-headed pachycephalosaurs, thought to engage in head butting, such as the Stegoceras; and the ceratopsians, four-legged animals with long, bony frills and horns, like the Triceratops.

Which major Cretaceous period dinosaurs were herbivores and carnivores?

All of the remaining sauropods, such as Saltasaurus, Alamosaurus, and Argentinosaurus, were plant eaters. The most numerous and diverse herbivores in the Cretaceous, however, were the ornithischians, including the duck-billed ornithopods, the horned ceratopsians, the thick-headed pachycephalosaurs, and the armored ankylosaurs. The major carnivorous dinosaurs of the Cretaceous period were from

the saurischian (lizard-hipped) groups, and were theropods. They included the large carnosaurs such as Giganotosaurus, Carcharodonotosaurus, and Tyrannosaurus, as well as the smaller, more agile dromaeosaurs, such as Velociraptor, Deinonychus, and Utahraptor. The list is huge, and more fossils of animals are found and added to the list each year.

How did the distribution of dinosaur species change during the Cretaceous period?

The earlier Triassic and Jurassic periods were characterized by joined landmasses throughout the planet. By the Cretaceous period, these landmasses began to separate, isolating some species of dinosaurs, and leading to different areas having a variety of new species. For example, the titanosaur sauropods were mostly present in former Gondwana, such as South America, while the ceratopsians and hadrosaurs were found mainly in Laurasia. But many of these fossil interpretations are highly debated. One of the main reasons for the present uncertainty about the overall distribution of dinosaurs is the incompleteness of the known dinosaur fossil record and the fragmentation of many dinosaur fossils found within rock layers.

What were some of the dinosaurs that lived during the Cretaceous period?

The number of dinosaurs that lived during the Cretaceous period was immense and too many to list here. As more fossils are found, the number will continue to grow. What follows is a partial listing of Cretaceous dinosaurs:

Cretaceous Period Dinosaurs

Raptors dinosaurs with prominent claws used for hunting, such as the Utahraptor were smaller than the Tyrannosaurus but made up for this by hunting in packs (Big Stock Photo).