Gressly (July 17, 1814 - April 13, 1965) was a Swiss geologist and paleontologist who was a pioneer, and regarded by some as the founder, of paleogeography. He is known for his work identifying stratigraphic facies (“aspects de terrain”) recognizing lateral regional variations in the character and fossil content of rock strata resulting from the environmental differences at the time of original deposition.
He wrote Observations Géologiques sur le Jura Soleurois on his studies of facies (a term he coined) he found in the Jura Mountains. His fossil collection had 25,000 specimens. He was appointed as an assistant to Louis Agassiz at Neuchâtel. The dinosaur Gresslyosaurus (Platyosaurus) was named in 1857 to honour him. From Today In Science History