who proposed what came to be called the Ordovician period (505 to 438 million years old) of geologic strata. Lapworth is famous for his work with marine fossils called graptolites.By fastidiously collecting the tiny, colonial sea creatures, he figured out the original order of layered rocks that had been faulted and folded in England's Southern Uplands. This method of correlating rocks with graptolites became a model for similar research throughout the world.
In 1879, Lapworth proposed a new classification of Lower Paleozoic rocks with the Ordovician, between the redefined Cambrian and Silurian periods. The name comes from an ancient Welsh tribe, the Ordovices. From Today In Science History