Between 19th and 20th centuries the scientific graphical representation became very popular in schools and universities. The University of Padua preserves some important historical collections of wall-charts, photographs and illustrated books. These documents show the importance scholars gave to images in communicating science to students and colleagues.

Dinosaurs (Dinosauria Owen, 1842) appeared during the Triassic (about 230 million years ago) and dominated the planet until the end of the Cretaceous (about 65 million years ago), when they disappeared in the Mesozoic mass extinction