Cambrian Period, the first geologic period of the Paleozoic Era. It began 570,000,000 years ago and lasted 70,000,000 years. It is named for Wales (which the Romans called Cambria), where sedimentary rocks of the period were first recognized.
Hieroglyphics used to be a language that no one -- Egyptian or otherwise -- could decipher. With the help of the Rosetta Stone, that all changed.
Over the years, archaeologists have excavated an abundance of important fossils from the La Brea Tar Pits, also known as Rancho La Brea. How knowledgeable are you about this prehistoric place of many a mammoth's demise?