However, this was a simple, and common, case of misidentification. Joseph Needham, a historian of China, wrote that the Chinese developed the Mercator projection hundreds of years before Mercator did, using it in star charts during the Song Dynasty. Snyder amended his assessment to 'a similar projection' in 1993. However, given the geometry of a sundial, these maps may well have been based on the similar central cylindrical projection, a limiting case of the gnomonic projection, which is the basis for a sundial. The projection found on these maps, dating to 1511, was stated by John Snyder in 1987 to be the same projection as Mercator's. German polymath Erhard Etzlaub engraved miniature 'compass maps' (about 10×8 cm) of Europe and parts of Africa that spanned latitudes 0°–67° to allow adjustment of his portable pocket-size sundials. There is some controversy over the origins of the Mercator. As a result, landmasses such as Greenland, Antarctica, Canada and Russia appear far larger than they actually are relative to landmasses near the equator, such as Central Africa. This inflation is very small near the equator but accelerates with increasing latitude to become infinite at the poles. As a side effect, the Mercator projection inflates the size of objects away from the equator. It became the standard map projection for navigation because it is unique in representing north as up and south as down everywhere while preserving local directions and shapes. The Mercator projection ( / m ər ˈ k eɪ t ər/) is a cylindrical map projection presented by Flemish geographer and cartographer Gerardus Mercator in 1569.

Mercator 1569 world map ( Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata) showing latitudes 66°S to 80°N. The Mercator projection with Tissot's indicatrix of deformation. Note the size comparison of Greenland and Africa. Cylindrical conformal map projection Mercator projection of the world between 85°S and 85°N.

Flat earth azimuthal map