"Adrienne Mayor, a classical folklorist and historian of science, proposed that the ancient Greek idea and image of the griffin in classical art and literature beginning in the 7th century BC was influenced in part by the fossilized remains of beaked dinosaurs such as Protoceratops observed on the way to gold deposits by nomadic prospectors of ancient Scythia (Central Asia),[18] This hypothesis is necessarily speculative. It draws on numerous Greek and Latin literary sources and related artworks in a specific time frame, beginning with the first written descriptions of griffins as real animals of Asia in a lost work by Aristeas (a Greek who travelled to the Altai region between Mongolia and NW China in the 7th century BC) cited by Aeschylus and Herodotus (ca. 450 BC) and ending with Aelian (3rd century AD), the last ancient author to report any "new" details about the griffin."