Radioactive dating is used to determine the age of fossils.
Extinct organisms represented only by fossils.
Radioactive dating is used to determine the age of extinct organisms.
What is used to determine the age of extinct organisms?
  viruses
  an electron microscope
  Echinoderm.
  fossils of Panthera leo
  genetic material
  the Sun
  tectonic plates coliding
  radioactive dating