Human footprints, and similar images, have been described from rocks on various continents: North and South America, Europe, Asia and Africa; on rocks of any age, including Precambrian metamorphics.

Many of these images are carved. The Precambrian “footprints” of North Georgia were carved on the modern rock surface, but are not within the rock. Weathering rates are so high that they can be only some hundreds of years old. The instep and all of the toes were sharply defined, as is characteristic of carvings. The number of toes was not constant from print to print. The Cretaceous “footprints” of Missouri were also sharply-defined carvings, although they appeared on the bedding plane. There are no “jumping” indentations at either heel or toe, even though the two prints (side by side) were completely isolated on a wide smooth surface. The Precambrian “footprints” of Sweden likewise are carvings, on the modern weathering surface, with sharply-detailed outlines.

Many more of these images are not footprints of any animal at all. They vary in size, shape, and depth of indentation. Just as carved images typically show too much sharp detail, these images do not show any detail, rarely resemble the correct shape, and commonly are not consistent in size. The Cretaceous “footprints” of central Texas are a hodge-podge of random markings of various kinds, the large majority of which were formed by differential erosion of a non-homogenous limestone. Whereas dinosaur footprints in the same rocks show systematic patterns and sequences, the so-called “human footprints” are erratic natural markings and excavations.

A tiny minority of these images was made by the feet of human or primitive humanoid creatures. These genuine footprints show recognizable patterns and sequences, but not much detail; occur on bedding planes; and date only from Pleistocene or late Pliocene rocks.