The SDNHM paleontology collections include over 153,000 numbered species lots. These lots vary in size from single specimens (e.g., an isolated mammal tooth) to suites of specimens (e.g., 300 shells of a particular species of marine snail), and represent over 1.5 million specimens. The specimens have been recovered from over 5,500 recorded collecting localities, primarily from southern California and northern Baja California, Mexico. There are 574 primary and 730 secondary types