Caloceras johnstoni Ammonite Fossil

These images are of the Caloceras johnstoni ammonite fossil. It was found on the Somerset coast of Dorset England. Creatures are from the Lower Jurassic Period in the Blue Lias strata. Fossils on display at the Lyme Regis Museum in England as of August 2016. Fossils are composed of aragonite.

Learn more at www.lymeregismuseum.co.uk

Sphenodiscus Aragonite Ammonite Fossil

Picture of aragonite ammonite shell fossil of a Sphenodiscus sp. The creature existed the late Cretaceous Period Upper Maastrichtian stage. Fossil was found in Fox Hills Formation of South Dakota USA. Specimen was on display at the Muséum National D'Histoire Naturelle Minéralogie et Géologie in Paris France (August 2016).

Learn more here:
http://www.mnhn.fr/fr/visitez/lieux/galerie-mineralogie-geologie