Fig. 4From: Geochemical evidence (C and Sr isotopes) for methane seeps as ammonite habitats in the Late Cretaceous (Campanian) Western Interior SeawaySeep-associated carbonates. a–c Sub-spheroidal concretions enclosing well-preserved shells of a lucinid, carbonate is Mg-rich calcite with minor amounts of apatite and pyrite (AMNH 64623, loc. 3528); b baculite (AMNH 64595, loc. 3545) and c scaphite (AMNH 64625, loc. 3528); d small pipe-like concretion (AMNH 64608, loc. 3528); e tube (AMNH 79109)Back to article page