This image is of a Dactylioceras tenuicostatum (YOUNG et BIRD, 1822) fossil. When collected, the fossil was originally labeled Ammonites annulatus (J. SOWERBY, 1819). It was found in England. The fossil dates to the Jurassic Period. It was displayed at Muséum National D'Historie Naturelle Jardin Des Plantes Paléontologie et Anatomie Comparée, Paris, France. Image taken August 2009.