Cretaceous time 145-66 million years ago |
 Click on photo for larger image. |
Click on photo for larger image. T. rex growls and lower jaw moves up and down when visitors press a button. |
Cretaceous dinosaurs New types replaced extinct forms. Plate tectonics continued to pull apart and create the Rocky Mountains. Inland seas and swamps advanced in many parts of the world. Nearly all longneck dinosaurs went extinct as uplands became wetlands and low, fast growing flowering plants appeared and overtook tall, slow growing cone bearers. New beaked dinosaurs munched on flowering plants and remained plentiful until the end of the Cretaceous when the last dinosaurs were extinct. |
Fossils on exhibit |
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|---|---|---|---|
| Name | Description | Location | Time |
| Deinonychus (possibly) | claw (cast) | Hell Creek Formation, Harding County, South Dakota | Late Cretaceous |
| duckbill dinosaur | femur | Hell Creek Formation, South Dakota | Cretaceous |
| Edmontonia | tooth | Lance Creek Formation, Graffam-Campbell Lease, Niobrara County, Wyoming | Late Cretaceous |
| Edmontosaurus annectens (cast) | Skin and section of jaw showing rows of teeth | Oldman Formation, Red Deer River, Alberta, near Brooks, Canada | Upper Cretaceous |
| gastroliths | Antlers sandstone, Cater County, Oklahoma | Early Cretaceous | |
| ostrich type dinosaur | egg shell fragments | Aix-en-Provence, France | Late Cretaceous |
| Pachycephalosaurus (dome-headed dinosaur) | tooth | Lance Creek Formation, Grafflam-Campbell lease, Niobrara County, Wyoming | Late Cretaceous |
| Protoceratops | egg (cast) | Flaming Cliffs, Gobi Desert, Mongolia | Cretaceous |
| Saltasaurus (possibly) | egg shell fragments | Allen Formation, Patagonia, Argentina | Late Cretaceous |
| Saurornitholestes langstoni (cast) | claw | Lance Creek Formation, Niobrara County, Wyoming | Late Cretaceous |
| Struthiomimus (ostrich dinosaur) | vertebra | Hell Creek Formation, Harding County, South Dakota | Late Cretaceous |
| Triceratops | trunk vertebra | Hell creek formation, South Dakota | Cretaceous |
| Triceratops horridus | tooth (cast) | Lance Creek Formation, Niobrara County, Wyoming | Late Cretaceous |
| Tyrannosaurus rex | brain cavity (cast) | Hell Creek Formation, Montana | Cretaceous |
| Tyrannosaurus rex | skull (cast) | Hell Creek Formation, Montana | Cretaceous |
| Velociraptor | claw (cast) | Djadochta Formation, Shabrark Usa, Mongolia | Late Cretaceous |
