Cambrian The earliest period of the Paleozoic era, spanning the time between 544 and 505 million years ago. It is named after Cambria, the Roman name for Wales, where rocks of this age were first studied. Campanian European stage of the Upper Cretaceous, spanning the time between 84 and 72 million years ago. Carboniferous A period of time in the Paleozoic era that includes the Pennsylvanian and Mississippian periods and extended from 360 to 286 million years ago. Cartilaginous Fishes Fish having a skeleton composed mostly of cartilage, as sharks and rays.
Cartilage is gristle or a firm, elastic, flexible type of connective tissue.
Cenomanian European stage of the lowermost Upper Cretaceous, spanning the time between 95 and 91 million years ago. Coccoliths Microscopic structures of varying shape and size that are made of calcite, are secreted by calcareous nannoplankton, and are found in marine deposits from the Triassic period to the Recent. Coccoliths range in size from one to thirty-five micrometers in size. Coniacian European stage of the Upper Cretaceous, spanning the time between 90 and 88 million years ago. Core A cylindrical section of rock, usually 2-4 inches in diameter and up to several feet long, that is the result of coring into the earth.