The Jurassic Period (named for the Jura Mountains between Switzerland and France) extended from about 202 million years ago until 141 million years ago. During the Jurassic, North and South America, Africa, and Australia were joined in a supercontinent near the equator. Europe and Asia had just broken off from the Pangean supercontinent.
There are few outcrops of Jurassic rock in North America, but the best-known of Jurassic strata, the Morrison Formation, is found in much of the Western interior of the U.S. It was during this time that the huge sauropod dinosaurs such as Apatasaurus and Brachiosaurus lived.
Sea level was low but rising during the Early Jurassic, and high throughout the remainder of the period. Climate, in general, was warm, in part due to the position of the land masses nearer the equator.
Classic Fossil-Bearing Sites
Lias Formation, England
Navajo Sandstone, Arizona
Solnhofen
Limestone, Germany
Morrison Formation, Colorado,
Utah, Wyoming
Several impact structures of Jurassic age are known. A 10 km structure about 200 million years old is found in North Dakota, and a similarly-dated one about 14 km in diameter is found in Tennessee. An 80 km craterform structure dated to about 183 mya is located in Puchezh, Russia, and a 23 km impact site from 160 mya is found in France.
Significant Events
Continental Breakup
The Permian-Triassic supercontinent of Pangaea began to break apart in the Jurassic, with the splitting off of the European-Asian component.
Himalayan Deposition
The rocks that would ultimately become the highest point on Earth were deposited in the Triassic and Jurassic Periods as limestones, dolomites, and shales.
Jurassic Graphics
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| Rhamphorhynchus |
Stenopterygius |
Plesiosaurus |
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| Allosaurus |
Allosaurus Teeth |
Allosaurus Forelimb |
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| Shrimp |
Sectioned Ammonite |
Plesiosaur |
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| Plesiosaur |
Horseshoe Crab |
Bone Bed |
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| Morrison Formation |
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