An ammonite–fish association from the Kimmeridgian (Upper Jurassic) of La Rochelle, western France





Romain Vullo [], Unidad de Paleontología, Departamento de Biología, Calle de Darwin, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain; Lionel Cavin [], Département de Géologie et de Paléontologie, Muséum d’Histoire naturelle, CP 6434, 1211, Genève 6, Switzerland; Vincent Clochard [], Institut Français du Pétrole, 1 and 4, avenue de Bois-Préau, 92852 Rueil-Malmaison, France


A partially disarticulated actinopterygian fish preserved in a large three-dimensional ammonite body chamber is described from the Kimmeridgian of western France. Taphonomic observations on the degree of preservation of the fish and the development of epibiont organisms on the inner wall of the shell indicate a rather long time interval before sediment totally filled the body chamber. The fish, referred to an indeterminate Macrosemiidae, probably used this empty ammonite (Rasenioides, Aulacostephanidae) shell as a refuge, or possibly for spawning and/or brooding. It can be assumed that ammonite shells may have constituted common shelters for demersal fishes living in an open-marine shelf environment, near to a muddy bottom devoid of rocks.