Hecticoceras sp. ammonite fossil collected from Jurassic sediments in Villers-sur-Mer, France. Hecticoceras is an extinct genus of ammonite which can be found in Mid to Upper Jurassic sediments; this particular specimens is of Oxfordonian age, that is approximately 167 to 153 Mya. They were nektonic carnivores which fell to the sea floor upon death. This ammonite only measures 1 cm in diameter, it has a smooth evolute shell and is supllied in a small plastic bag with an information label.