Escher first works over the Halfplane model
Obras de Escher sobre el modelo del semiplano
Escher begins to work on hyperbolic geometry using the model of the halfplane near 1956. After some transitional works, it's in the drawing Regular Division of the Plane VI (1957) that we can see the geometry more clearly. The tesselae almost adjust the lines (geodesic) in the halfplane, which should coincide with the lower side of the lizards.
A beam of parabola in sky blue color, marks the spine of the first rows tessellated with lizards.