Smithsonian Natural History Museum

Triassic Diorama pages

Early - Middle Jurassic Diorama pages

Smoithsonian natural History Diorama

LateJurassic Diorama pages

Early - Middle Cretaceous Diorama pages

Natural History Museum Cretaceous DioramaLate Cretaceous Diorama pages

More Diorama and pages


update 110312

Smithsonian Naturak History Museum

The Mesozoic starts in the Triassic 248 million years ago.  The Permian extinction wipped the board with the lose of 80% of speices. Inititally dominated by the survivors from the Permian. The the environment is improverished with low oxygen levels. The continents are joined together in the supper contintent Pangea. The central and equitorial is arid. Life is most common in the at the northern and southern latitudes with a some coastal areas.

Early Jurassic 201 million years ago, about 50% of all terrestrial vertebrate families were wiped out at the end of the Triassic. Pangaea the world continent begins to break up.   Plants exhibit a low diversity, dominated by primitive conifers.  The new flora favored high browsing herbivores like the prosauropods.  The first large theropods appear.

In the Middle Jurassic cycadoids start to become less common, conifers get much bigger and cycads are more prominent and the climate gets wetter as Pangaea starts to break up. Sauropods become the large herbivore in the Middle Jurassic. 

The Late Jurassic starts 201 million years ago. Pangaea had begun to seperate into Laurasia to the north and Gondwana to the south. Dinosaur population begin the to become more divrese as the populations are isolated. Deserts of the Triassic were replaced by forests. Conifer families flourished dominated vegetation, as did the shrubby Bennettitales low latitude. Cycads, ginkgos and tree ferns are common. Smaller ferns were probably the dominant undergrowth.

In the Early Cretaceous 144 - 99  million years ago, Pangaea breaks up and the plants start to change with the first flowering plants starting to appear.  Conifers and and ferns are still common and wide spread. Iguanodonts diversify and become wide spread becoming.

Smithsonian Natural history Creataceous Diorama

The Late Cretaceous 99 - 65 million years ago, is the final era of the Mesozoic. Flower plants are wide spread in the northern continents of Laurasia. This is the most diverse period for dinosaurs.