Definition that contains cretaceous period
- tyrannosaurus large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America
- iguanodon massive herbivorous bipedal dinosaur with a long heavy tail; common in Europe and northern Africa; early Cretaceous period
- tyrannosaur large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America
- coelacanth fish thought to have been extinct since the Cretaceous period but found in 1938 off the coast of Africa
- ibero-mesornis sparrow-sized fossil bird of the Cretaceous period having a vestigial tail; found in Spain; considered possibly the third most primitive of all birds
- trachodont large duck-billed dinosaur of the Cretaceous period
- latimeria chalumnae fish thought to have been extinct since the Cretaceous period but found in 1938 off the coast of Africa
- sinornis sparrow-sized fossil bird of the Jurassic period to the Cretaceous period having a keeled breastbone and vestigial tail; found in China; considered possibly the second most primitive of all birds
- tyrannosaurus rex large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America
- genus struthiomimus small toothless saurischian dinosaurs; later Cretaceous period in Canada