411 REFERENCE · Wikibooks
World of Dinosaurs/Dinosaurs Through Time
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Here we show a rough schematic of the TIMETREE of dinosaurs as they proliferated throughout the Mesozoic.
Fossils from Triassic rocks show few dinosaurs, and these animals are relatively small and basal in their anatomy. Dinosaur fossils are much more common, and show greater animal diversity, in Jurassic rocks. Finally, the most famous and culturally iconic dinosaurs (Tyrannosaurus, Triceratops, etc.) are known from fossils in Cretaceous rocks.