Why are Middle Jurassic fossils rare?

Middle Jurassic rock layers are less exposed at the surface today than Early or Late Jurassic deposits, making fossils harder to find. But new discoveries from China, England, and Argentina are filling in the gaps.

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Middle Jurassic Period

174-163 million years ago

The Middle Jurassic saw dinosaurs establishing themselves as the dominant land animals. True sauropods were reaching enormous sizes, the first stegosaurs appeared, and theropod predators were growing more diverse and specialized. Unfortunately, Middle Jurassic fossils are relatively rare, making this an exciting frontier of paleontology.

Fun Facts

✓Middle Jurassic fossils are less common than Late Jurassic ones, making discoveries from this period especially valuable.
✓The first true stegosaurs appeared during the Middle Jurassic.
✓Megalosaurus, the first dinosaur ever scientifically described, lived in the Middle Jurassic of England.
✓China has produced some of the best Middle Jurassic dinosaur fossils, including early ceratosaurs and sauropods.

Questions About the Middle Jurassic

Dinosaurs of the Middle Jurassic Period

Agilisaurusaj-ih-lee-SORE-us Cetiosaurussee-TEE-oh-sore-us GasosaurusGAS-oh-SORE-us Huayangosaurushoy-YANG-oh-SORE-us Monolophosaurusmono-LOH-foh-sore-us XuanhanosaurusSHWAN-han-oh-SOR-us

Other Prehistoric Periods

Triassic Late Triassic Middle Triassic Jurassic Early Jurassic Late Jurassic Middle-Late Jurassic Late Jurassic-Early Cretaceous View all periods →