Sources and limits
Each piece of continental crust from an open plate model is draped with today's satellite imagery, then turned on the globe by its own plate's rotation for the age you pick. Between the pieces is ocean floor that has since been destroyed.
What the surface shows
The colours are today's surface carried back in time. Ice, deserts, forests and coastlines are modern, so an icy Antarctica sitting near the equator 500 million years ago is a reminder of that, not a claim about the past. Ancient shorelines, seas and mountains are not modelled.
Cities before their ground existed
Some cities stand on crust that the model only creates later, for example the mountain belt under Rio de Janeiro, which forms as Gondwana assembles about 520 million years ago. Before that age the city shows as a hollow ring labelled with the age its crust appears.
Poles
N and S mark Earth's spin axis. The model keeps the axis fixed and moves the plates across it, which is how palaeomagnetism records ancient latitude.
Uncertainty
Before about 250 Ma, palaeomagnetism constrains latitude only, so east-west positions are the model's best fit. Pacific absolute positions between 250 and 83 Ma are adjusted in the model.
Sources
Plate model: Merdith, A.S. et al. (2021), A continuous, kinematic full-plate motion model from 1 Ga to present, Earth-Science Reviews 214, 103477, with coastline and static-polygon shapes from the same model (CC BY 4.0, via the EarthByte group's GPlates Web Service repository). Rotations computed with pyGPlates and replayed in your browser as quaternions, interpolated between 5 Myr steps. Imagery: NASA Earth Observatory, Blue Marble Next Generation with topography and bathymetry, July 2004 (Reto Stöckli). Geologic time scale and period colours: International Commission on Stratigraphy, ICS chart 2023/09. City search: GeoNames (CC BY 4.0), places of 15,000 people or more. Rendering: three.js.