Jurassic Period
201.4 – 145 million years ago · Mesozoic Era
The Jurassic is the classic age of giant dinosaurs. Sauropods grew to enormous sizes, and the first birds evolved from small feathered theropods, all while Pangea came apart.
At a glance
- Began
- 201.4 Ma
- Ended
- 145 Ma
- Duration
- 56.4 million years
- Era
- Mesozoic
- Climate state
- Greenhouse (warm, little or no polar ice)
- Land above sea level (PaleoDEM)
- ~33.2%
- Dinosaurs on our map
- 4
The world in the Jurassic
Open the interactive map at 170 Ma → Elevation view Show dinosaurs on the map
What Earth was like
Pangea split into Laurasia in the north (North America, Europe and Asia) and Gondwana in the south. The central Atlantic Ocean began to open, and shallow seas covered much of Europe, leaving the limestone of the Jura Mountains that gave the period its name.
Climate
The climate was warm and generally humid, with no permanent polar ice. Forests of conifers, cycads and ginkgos reached high latitudes, and plants grew in regions that are polar today.
Life
Sauropods such as Diplodocus and Brachiosaurus, plated Stegosaurus and the predator Allosaurus dominated the Late Jurassic, famously preserved in the Morrison Formation of North America. Archaeopteryx, around 150 million years ago, shows a mix of dinosaur and bird features. Ichthyosaurs and plesiosaurs ruled the seas.
Dinosaurs of the Jurassic
These genera from our map lived during the Jurassic. Bars show each genus’s accepted time range within the period.
- Diplodocus
- Allosaurus
- Stegosaurus
- Archaeopteryx
Silhouettes via PhyloPic: Diplodocus — Jagged Fang Designs, CC0 1.0 (PhyloPic) · Allosaurus — Jagged Fang Designs, CC0 1.0 (PhyloPic) · Stegosaurus — Connor Ashbridge, CC BY 4.0 (PhyloPic) · Archaeopteryx — Scott Hartman, CC0 1.0 (PhyloPic)
How it ended
The Jurassic ended without a major mass extinction; its boundary with the Cretaceous, set at about 145 million years ago, is one of the least precisely defined in the time scale.
Key facts
- Stegosaurus and T. rex were separated by about 80 million years, more time than separates T. rex from us.
- Archaeopteryx fossils come from the Solnhofen limestone in Germany.
- The Atlantic Ocean began to open during the Jurassic.
Data: land and sea
Across the Jurassic, an average of 33.2% of Earth’s surface stood above reconstructed sea level (range 28.9–38.6%). Today the same model gives 31.8%.
Where this data comes from
- Continent positions: GPlates Web Service, Müller et al. (2019) plate model, covering 0–250 Ma.
- Elevation and shorelines: PALEOMAP PaleoDEMs, Scotese & Wright (2018), doi:10.5281/zenodo.5460860, CC BY 4.0.
- Dinosaur fossils: Paleobiology Database occurrence records.
- Period boundaries: ICS International Chronostratigraphic Chart (2023/09).
These are scientific reconstructions, not observations. Uncertainty grows the further back in time you go. About & data sources
Related reading
Keep exploring
- Geological periodsTwelve periods, each with a map, dinosaurs and climate.
- Earth's history4.5 billion years in one story, from a molten planet to today.
- Plate tectonicsHow plates move, collide and build mountains and oceans.
- LearnArticles on countries, dinosaurs and supercontinents.
- FAQQuick answers about Pangea and the map.
- About & data sourcesWhere the reconstructions and fossil data come from.