Fig. 5From: Geochemical evidence (C and Sr isotopes) for methane seeps as ammonite habitats in the Late Cretaceous (Campanian) Western Interior SeawaySEM images showing examples of preservation in shell material in a specimens of a Baculites compressus (AMNH 64694) and b Eutrephoceras dekayi (AMNH 64695) collected at a methane seep in the B. compressus Zone (AMNH loc. 3528). The SEM preservation index (Cochran et al. 2010) is 5 (excellent) in bothBack to article page