LARGE FOSSIL AMMONITE (diameter 25 cm) and fossil with a variety of ammonites and fragments of different sizes; about 150-180 million years old, probably Ataxioceras speo (lower Kimmeridgian). Ammonites (Ammonoidea) are an extinct subgroup of cephalopods and, over a period of about 350 million years from their first appearance in the Lower Devonian to their extinction at the end of the Cretaceous. Large ammonite: H. 21.5 x L. 30.5 x w. 8 cm; weight 4208 g. Petrifaction with several ammonites: H. 13.5 x L. 17.5 x W. 7.5 cm; weight 1522 g.