Jurassic Period

Jurassic Period (₂₀₁–145 million years ago)

The Jurassic Period is when dinosaurs become dominant land animals and grow to huge sizes.

World & Climate

• Pangaea begins to break apart into separate landmasses (Laurasia in the north, Gondwana in the south).
• Climate becomes generally warm, humid, and more even worldwide, supporting lush forests.

Dinosaurs in the Jurassic

Key trends:

• Explosion of large sauropod dinosaurs (long‑necked herbivores).
• Diverse theropod predators.
• Early stegosaurs and other armored dinosaurs appear.

Examples of well‑known Jurassic dinosaurs:

• Sauropods – e.g., Diplodocus, Brachiosaurus, Apatosaurus.
• Theropods – e.g., Allosaurus, Ceratosaurus.
• Stegosaurs – e.g., Stegosaurus with its plates and tail spikes.

Other Life

• Pterosaurs are common in the skies.
• Seas are full of marine reptiles like ichthyosaurs and plesiosaurs.
• Early birds (e.g., Archaeopteryx) appear in the Late Jurassic, showing feathers and features linking them to small theropod dinosaurs.

The Jurassic sets the stage for the even greater diversity of dinosaurs in the Cretaceous.