What did Earth look like during the Jurassic?
The Jurassic began 201.4 million years ago and ended 143.1 million years ago. It is the one period on this site where the water came back: the share of the world below sea level rose from 61.4% to 66%.
At the start
About 200 million years ago, near the start of the Jurassic. The source calls this map the Late Triassic.
Yellow is land, mid-blue is shallow sea, dark blue is deep ocean. The map is drawn flat, so places near the poles look wider than they really are.
This is one model’s answer, not a photograph. It shows the world about 200 million years ago — the age of the map itself, which is the closest the source gets to the ages on this site.
Map data: Scotese, C. R., & Wright, N. M. (2018). PALEOMAP Paleodigital Elevation Models (PaleoDEMS) for the Phanerozoic (Version 2) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.5460860 Licensed CC BY 4.0. Grid 360×180 at 1° — about 111 km per cell at the equator, so nothing the size of a town can be read from it.
At the end
About 145 million years ago, near the end of the Jurassic. The source calls this map the Jurassic-Cretaceous Boundary.
Yellow is land, mid-blue is shallow sea, dark blue is deep ocean. The map is drawn flat, so places near the poles look wider than they really are.
This is one model’s answer, not a photograph. It shows the world about 145 million years ago — the age of the map itself, which is the closest the source gets to the ages on this site.
Map data: Scotese, C. R., & Wright, N. M. (2018). PALEOMAP Paleodigital Elevation Models (PaleoDEMS) for the Phanerozoic (Version 2) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.5460860 Licensed CC BY 4.0. Grid 361×181 at 1° — about 111 km per cell at the equator, so nothing the size of a town can be read from it.
Put the two side by side and the great land mass has begun to come apart — you can see water pushing into gaps that were not there before. The share below sea level went from 61.4% to 66%, a rise of 4.6 points.
The number nobody remembers correctly
Ask almost anyone — including most books — when the Jurassic ended and you will hear 145 million years ago. The chart this site cites says 143.1. The boundary was measured again, and the number moved.
That is worth knowing for its own sake. Dates in Earth science are measurements, not facts handed down, and measurements get better. Every age on this site is read from a published chart at a fixed version rather than typed from memory, precisely so that when the number moves, the site moves with it instead of quietly staying wrong.
The dinosaurs people picture when they hear “Jurassic” walked through this world. What was dug up near a particular town, though, is on that town’s page — Bath has the richest record here.
Where this comes from
- The maps
- PALEOMAP Paleodigital Elevation Models (PaleoDEMS) for the Phanerozoic, version 2. Scotese, C. R., & Wright, N. M. (2018). PALEOMAP Paleodigital Elevation Models (PaleoDEMS) for the Phanerozoic (Version 2) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.5460860 Licensed CC BY 4.0. Read from a copy whose checksum is recorded in this repository, so the numbers on this page can be checked against the exact file they came from.
- How sure is this?
- Every map here is a reconstruction — an estimate built from evidence, not a photograph. Its authors call each one the “best guess” or average geography for the time it represents, which is a fair description and worth repeating. 1° cells — roughly 111 km at the equator. Nothing at the scale of a town can be read from this grid. The source grid is 5 million years. An age between two maps is NOT interpolated: the nearest map is used and its own age is what gets published.
One reconstruction among several. PALEOMAP draws the world here; MULLER2019 places individual points elsewhere on this site. They are different models and are never composited or averaged.
Read from the source archive on .