title: List of plesiosaur-bearing stratigraphic units
text: # List of plesiosaur-bearing stratigraphic units
  
  | Group or Formation | Period | Country |
  | - | - | - |
  | Adaffa Formation | Cretaceous | Saudi Arabia |
  | Agardhfjellet Formation | Jurassic | Norway |
  | Agrio Formation | Cretaceous | Argentina |
  | Akrabou Formation | Cretaceous | Morocco |
  | Allaru Mudstone Formation | Cretaceous | Australia |
  | Allen Formation | Cretaceous | Argentina |
  | Alum Shale Formation | Jurassic | United Kingdom |
  | Ampthill Clay Formation | Jurassic | United Kingdom |
  | Ancholme Group/Kimmeridge Clay Formation | Jurassic | United Kingdom |
  | Ancholme Group/Oxford Clay Formation | Jurassic | France United Kingdom |
  | Arauco Group/Quiriquina Formation | Cretaceous | Chile |
  | Arcillas de Morella Formation | Cretaceous | Spain |
  | Arctic Red Formation | Cretaceous | Canada |
  | Argiles de Châtillon Formation | Jurassic | France |
  | Argiles de Montaubert Formation | Jurassic | France |
  | Argille Varicolori Formation | Cretaceous | Italy |
  | Artemesia Formation | Jurassic | Cuba |
  | Artoles Formation | Cretaceous | Spain |
  | Ashville Formation | Cretaceous | Canada |
  | Balqa Group/Phosphorite Unit Formation | Cretaceous | Jordan |
  | Barrow Formation | Cretaceous | Australia |
  | Barrow Group/Birdrong Sandstone Formation | Cretaceous | Australia |
  | Bearpaw Formation | Cretaceous | Canada United States |
  | Bearpaw Shale Formation | Cretaceous | United States |
  | Belly River Formation | Cretaceous | Canada |
  | Belly River Group/Dinosaur Park Formation | Cretaceous | Canada |
  | Bissekty Formation | Cretaceous | Uzbekistan |
  | Blue Lias Formation | Jurassic | United Kingdom |
  | Braunjura Group/Braunjura alpha & Braunjura beta Formation | Jurassic | France |
  | Bückeberg Formation | Cretaceous | Germany |
  | Calcaire de Caen Formation | Jurassic | France |
  | Calcaire à Bélemnites Formation | Jurassic | France |
  | Calcaires de MoulinFormation | Jurassic | France |
  | Calcaires à Spatangues Formation | Cretaceous | France |
  | Calcareous Grit Formation | Jurassic | United Kingdom |
  | Carlile Shale Formation | Cretaceous | United States |
  | Chalk Formation | Cretaceous | United Kingdom |
  | Chalk Group/"Upper Chalk" Formation | Cretaceous | United Kingdom |
  | Chalk Group/Lower Chalk Formation | Cretaceous | United Kingdom |
  | Chalk Group/LowerFormation | Cretaceous | United Kingdom |
  | Chalk Group/LowerFormation | Cretaceous | United Kingdom |
  | Champion Bay Group/Colalura Sandstone Formation | Jurassic | Australia |
  | Charmouth Mudstone Formation | Jurassic | United Kingdom |
  | Chico Formation | Cretaceous | United States |
  | Chico Group/Moreno Formation | Cretaceous | United States |
  | Clearwater Formation | Cretaceous | Canada |
  | Colorado Group/Belle Fourche Formation | Cretaceous | Canada United States |
  | Colorado Group/Carlile Shale Formation | Cretaceous | United States |
  | Colorado Group/Graneros Shale Formation | Cretaceous | United States |
  | Colorado Group/Greenhorn Limestone Formation | Cretaceous | United States |
  | Colorado Group/Niobrara Formation | Cretaceous | Canada United States |
  | Conway Formation | Cretaceous | New Zealand |
  | Conway Siltstone Formation | Cretaceous | New Zealand |
  | Coon Creek Formation | Cretaceous | United States |
  | Coral Rag Formation | Jurassic | United Kingdom |
  | Corallian Oolite Formation | Jurassic | United Kingdom |
  | Corallian Group/Coral Rag Formation | Jurassic | United Kingdom |
  | Corallian Group/Kingston Formation | Jurassic | United Kingdom |
  | Couche III Formation | Cretaceous | Morocco |
  | Cuyo Group/Los Molles Formation | Jurassic | Argentina |
  | Dinosaur Park Formation | Cretaceous | Canada |
  | Dorotea Formation | Cretaceous | Chile |
  | Duwi Formation | Cretaceous | Egypt |
  | Eagle Ford Formation | Cretaceous | United States |
  | Eagle Ford Group/Britton Formation | Cretaceous | United States |
  | Estratos de Quebrada Municipalidad Formation | Cretaceous | Chile |
  | Eutaw Formation | Cretaceous | United States |
  | Evergreen Formation | Jurassic | Australia |
  | Favel Formation | Cretaceous | Canada |
  | Fernie Formation | Jurassic | Canada |
  | Frontier Formation | Cretaceous | United States |
  | Futaba Group/Ashizawa Formation | Cretaceous | Japan |
  | Futaba Group/Tamayama Formation | Cretaceous | Japan |
  | Great Estuarine Formation | Jurassic | United Kingdom |
  | Great Estuarine Series Group/Estheria Shales Formation | Jurassic | United Kingdom |
  | Great Estuarine Group/Lealt Shale Formation | Jurassic | United Kingdom |
  | Great Oolite Formation | Jurassic | France |
  | Gres de Mortinsart Formation | Triassic | Belgium |
  | Grès de Infralias Formation | Triassic | France |
  | Grünsandstein Formation | Cretaceous | Germany |
  | Hailey Shales Formation | Cretaceous | United States |
  | Hasle Formation | Jurassic | Denmark |
  | Hastings Formation | Cretaceous | United Kingdom |
  | Hastings Beds Group/Wadhurst Clay Formation | Cretaceous | United Kingdom |
  | Hell Creek Formation | Cretaceous | United States |
  | Hiccles Cove Formation | Jurassic | Canada |
  | Hornerstown Formation | Cretaceous | United States |
  | Isachsen Formation | Cretaceous | Canada |
  | Itapecuru Formation | Cretaceous | Brazil |
  | Alcântara Formation | Cretaceous | Brazil |
  | Jagua Formation | Jurassic | Cuba |
  | Jagüel Formation | Cretaceous | Argentina |
  | Judith River Formation | Cretaceous | Canada United States |
  | Kajlâka Formation | Cretaceous | Bulgaria |
  | Kangauz Formation | Cretaceous | Russian Federation |
  | Kanguk Formation | Cretaceous | Canada |
  | Katiki Formation | Cretaceous | New Zealand |
  | Katrol Formation | Jurassic | India |
  | Kimmeridge Clay Formation | Jurassic | France United Kingdom |
  | Kunrade Formation | Cretaceous | Netherlands |
  | La Cabana Formation | Cretaceous | Spain |
  | La Caja Formation | Jurassic | Mexico |
  | La Casita Formation | Jurassic | Mexico |
  | La Colonia Formation | Cretaceous | Argentina |
  | La Luna Formation | Cretaceous | Venezuela |
  | Lajas Formation | Jurassic | Argentina |
  | Lake Waco Formation | Cretaceous | United States |
  | Laramie Formation | Cretaceous | United States |
  | Lias Formation | Jurassic | United Kingdom |
  | Lias Formation | Jurassic | United Kingdom |
  | Lias Group/Blue Lias Formation | Jurassic | United Kingdom |
  | Lias Group/Charmouth Mudstone Formation | Jurassic | United Kingdom |
  | Lias Group/Dyrham Formation | Jurassic | United Kingdom |
  | Lias Group/Marlstone Rock Formation | Jurassic | United Kingdom |
  | Lias Group/Scunthorpe Mudstone Formation | Triassic | United Kingdom |
  | Lias Group/Waterloo Mudstone Formation | Jurassic | United Kingdom |
  | Lias Group/Whitby Mudstone Formation | Jurassic | United Kingdom |
  | Lopez de Bertodano Formation | Cretaceous | Antarctica |
  | Los Alamitos Formation | Cretaceous | Argentina |
  | Lower Chalk Group/Cambridge Greensand Formation | Cretaceous | United Kingdom |
  | Lower Green Sand Formation | Cretaceous | Russian Federation |
  | Lower Greensand Group/Faringdon Sand Formation | Cretaceous | United Kingdom |
  | Lower Greensand Group/Hythe Formation | Cretaceous | United Kingdom |
  | Luxembourg Sandstone Formation | Jurassic | Luxembourg |
  | López de Bertodano Formation | Cretaceous | Antarctica |
  | Maaree Group/Bulldog Shale Formation | Cretaceous | Australia |
  | Maastricht Formation | Cretaceous | Belgium Netherlands |
  | Malargue Group/Roca Formation | Cretaceous | Argentina |
  | Malargüe Formation | Cretaceous | Argentina |
  | Malargüe Group/Allen Formation | Cretaceous | Argentina |
  | Malargüe Group/Loncoche Formation | Cretaceous | Argentina |
  | Mannville Group/Clearwater Formation | Cretaceous | Canada |
  | Marambio Group/Snow Hill Island Formation | Cretaceous | Antarctica |
  | Marnes de Dives Formation | Jurassic | France |
  | Marnes de Gravelotte (=La Gravclotte Marls) Formation | Jurassic | France |
  | Marree Group/Bulldog Shale Formation | Cretaceous | Australia |
  | Mata Amarilla Formation | Cretaceous | Argentina |
  | Mata Group/Tahora Formation | Cretaceous | New Zealand |
  | Melovatka Formation | Cretaceous | Russian Federation |
  | Mesaverde Formation | Cretaceous | United States |
  | Middle Keuper Group/Knollenmergel Formation | Triassic | Switzerland |
  | Middle Keuper Group/Trossingen Formation | Triassic | Germany |
  | Middle Yezo Formation | Cretaceous | Japan |
  | Middle Yezo Group/Chenaibo Formation | Cretaceous | Japan |
  | Molecap Greensand | Cretaceous | Australia |
  | Monmouth Group/Navesink Formation | Cretaceous | United States |
  | Mont Formation | Jurassic | France |
  | Montana Group/Pierre Shale Formation | Cretaceous | United States |
  | Moreno Formation | Cretaceous | United States |
  | Navesink Formation | Cretaceous | United States |
  | Nekum Formation | Cretaceous | Netherlands |
  | Neuquén Group/Anacleto Formation | Cretaceous | Argentina |
  | Newcastle Formation | Triassic | New Zealand |
  | Niobrara Formation | Cretaceous | United States |
  | Otway Group/Eumeralla Formation | Cretaceous | Australia |
  | Oxford Clay Formation | Jurassic | United Kingdom |
  | Paja Formation | Cretaceous | Colombia |
  | Paso del Sapo Formation | Cretaceous | Argentina |
  | Penarth Group/Westbury Formation | Triassic | United Kingdom |
  | Penarth Group/White Lias Formation | Triassic | United Kingdom |
  | Pender Formation | Cretaceous | Canada |
  | Pernarth Group/Westbury Formation | Triassic | United Kingdom |
  | Pierre Shale Formation | Cretaceous | Canada United States |
  | Point Lookout Formation | Cretaceous | United States |
  | Portland Oolite Formation | Jurassic | United Kingdom |
  | Portland Group/Portland Stone Formation | Jurassic | United Kingdom |
  | Posidonia Shale | Jurassic | Germany |
  | Purbeck Formation | Cretaceous, Jurassic | United Kingdom |
  | Purbeck Group/Lulworth Formation | Cretaceous, Jurassic | United Kingdom |
  | Puskwaskau Formation | Cretaceous | Canada |
  | Querecual Formation | Cretaceous | Venezuela |
  | Quiriquina Formation | Cretaceous | Chile |
  | Raritan Formation | Cretaceous | United States |
  | Razorback Beds Formation | Jurassic | Australia |
  | Rio del Lago Formation | Triassic | Italy |
  | Rodiles Formation | Jurassic | Spain |
  | Rolling Downs Group/Griman Creek Formation | Cretaceous | Australia |
  | Rolling Downs Group/Toolebuc Formation | Cretaceous | Australia |
  | Rolling Downs Group/Wallumbilla Formation | Cretaceous | Australia |
  | Rolling Downs Group/Winton Formation | Cretaceous | Australia |
  | Rosablanca Formation | Cretaceous | Colombia |
  | Rosso Ammonitico Veronese Formation | Jurassic | Italy |
  | Rybushka Formation | Cretaceous | Russian Federation |
  | Sables de Glos Formation | Jurassic | France |
  | Saint Formation | Cretaceous | Belgium |
  | Santa Marta Formation | Cretaceous | Antarctica |
  | Savel'evsk oil shales Formation | Jurassic | Russian Federation |
  | Scalpa Sandstone Formation | Jurassic | United Kingdom |
  | Selborne Group/Upper Greensand Formation | Cretaceous | United Kingdom |
  | Selma Group/Mooreville Chalk Formation | Cretaceous | United States |
  | Severn Formation | Cretaceous | United States |
  | Snow Hill Island Formation | Cretaceous | Antarctica |
  | Speeton Clay Formation | Cretaceous | United Kingdom |
  | Spilsby Sandstone Formation | Jurassic | United Kingdom |
  | Staffin Bay Formation | Jurassic | United Kingdom |
  | Strzelecki Group/Wonthaggi Formation | Cretaceous | Australia |
  | Sundance Formation | Jurassic | United States |
  | São Gião Formation | Jurassic | Portugal |
  | Tadi Beds Formation | Cretaceous | Angola |
  | Taylor Marl' Formation | Cretaceous | United States |
  | Tessé Sandstones Formation | Jurassic | France |
  | Thermopolis Shale Formation | Cretaceous | United States |
  | Tioriori Group/Takatika Grit Formation | Cretaceous | New Zealand |
  | Toolebuc Formation | Cretaceous | Australia |
  | Tropic Shale Formation | Cretaceous | United States |
  | Trossingen Formation | Triassic | Switzerland |
  | Tugulu Group/Lianmugin Formation | Cretaceous | China |
  | Uitenhage series Formation | Cretaceous | South Africa |
  | Uitenhage Group/Sundays River Formation | Cretaceous | South Africa |
  | Upper Chalk Formation | Cretaceous | United Kingdom |
  | Upper Gondwana Group/Umia Formation | Jurassic | India |
  | Upper Greensand Formation | Cretaceous | United Kingdom |
  | Upper Keuper Group/Exter Formation | Triassic | Germany |
  | Vaca Muerta Formation | Cretaceous, Jurassic | Argentina |
  | Vermillion River Formation | Cretaceous | Canada |
  | Wallumbilla Formation | Cretaceous | Australia |
  | Waterloo Formation | Jurassic | United Kingdom |
  | Weald Clay Group/Upper Weald Clay Formation | Cretaceous | United Kingdom |
  | Wealden Group/Tunbridge Wells Sand Formation | Cretaceous | United Kingdom |
  | Wealden Group/Vectis Formation | Cretaceous | United Kingdom |
  | Whitby Mudstone Formation | Jurassic | United Kingdom |
  | Wilczek Formation | Triassic | Russian Federation |
  | Wilgunya Group/Toolebuc Formation | Cretaceous | Australia |
  | Wilhelmøya Formation | Triassic | Norway |
  | Xiashaximiao Formation | Jurassic | China |
  | Ziliujing Formation | Jurassic | China |
  