Simple categories matching prehistoric:

• mammal,
• site,
• animal,
• giant,
• item,
• critter,
• reptile,
• dinosaur,
• tool,
• creature,
• artifact,
• beast,
• relic,
• artefact,
• survivor,
• monument,
• material,
• organism,

Members with property prehistoric:

• mammoth,
• dinosaur,
• animal,
• rhino,
• stone_tool,
• antique_nail,
• burin,
• mastodon,
• bone_tool,
• camel,
• brontosaurus,
• brontosaur,
• iron_tool,
• woolly_mammoth,
• rock_tool,
• pterosaur,
• shell,
• plesiosaur,
• primitive_reptile,
• prehistoric_mammal,
• bison,
• squid,
• lungfish,
• weapon,
• plankton,
• pelycosaur,
• marine_reptile,
• immense_insect,
• horse,
• crinoid,
• wild_horse,
• hairy_rhinoceros,
• painted_wood,
• woolly_rhinoceros,
• rhinoceros,
• knife,
• triceratops,
• sabertooth_cat,
• tyrannosaur,
• giant_sloth,
• mortar,
• wooly_rhino,
• sloth,
• ceramics,
• matting,
• flying_pterosaur,
• lion,
• grinding_stone,
• indian_pottery,
• trilobite,
• manatee,
• dinosaur_bones,
• gulf_sturgeon,
• fishing_implement,
• wooly_mammoth,
• ichthyosaur,
• huge_jar,
• cairn,
• ancient_shark,
• pterodactyl,
• early_rhino,
• dinosaur_poop,
• fossil_bones,
• skeleton,
• plant,
• lynx,
• scraper,
• earthenware,
• colored_earthenware,
• giant_reptile,
• flat_ax,
• moose,
• projectile_point,
• assorted_dinosaur,
• iguanodon,
• gomphothere,
• dire_wolf,
• dimetrodon,
• huge_roach,
• pottery,
• marsupial_lion,
• sabertooth_lion,
• alligator,
• actual_dinosaur,
• long_pestle,
• clothing,
• stone,
• sandal,
• dugong,
• tyrannosaurus,
• hippo,
• shell_adze,
• swimming_plesiosaur,
• frog,
• sabertoothed_cat,
• extinct_camel,
• tool,
• sabertoothed_tigers,
• turtle,
• sauropod,
• tapir,
• crocodile,
• arrow_point,
• shell_midden,
• hyena,
• giant_bison,
• bronze_ware,
• shark,
• steppe_bison,
• sabertooth_tigers,
• clovis_point,
• bone_pendant,
• reindeer,
• waste,
• projectile,
• wild_deer,
• algae_morgan,
• reptile,
• giant,
• fort,
• elephant,
• ancient_pottery,
• bronze,
• sturgeon,
• stone_pillar,
• stoneware,
• ancient_earthwork,
• fossil,
• sabertoothed_tiger,
• woolly_rhino,
• pelycosaur_dimetrodon,