Complex sentence: The Tarphycerida were the first of the coiled cephalopods, found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian.
Split into simpler sentences: The Tarphycerida were the first of the coiled cephalopods. They are found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian.