#11.) Phacops. It lived in the late Devonian Period (~400 million years ago).
#12.) Carbon-14 is a good radioactive isotope for determing the age of artifacts from a burial site thought to be associated with the most recent early humans because it is present in all organic matter (which humans have, of course).
#13.) 3, Devonian.
#14.) From the Devonian Period through the Triassic Period.
#15.) Cenozoic.
