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

Opal Belemnite Fossils

The original aragonite internal shell dissolved and was replaced by opal in these belemnite fossils. They existed the Cretaceous Period. Fossils were found in Coober Pedy, Australia. 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

Benthosuchus Fossil Amphibian Skull

Picture is of a Benthosuchus sushkini amphibian skull fossil. It dates to the Triassic Period. Fossil found in Scharzhenga River of Vachnevo Russia. Extinct creature is a distant relative to today's salamanders and frogs. It lived in rivers and lakes of what is now eastern Europe.

Fossil on display August 2016 in Natural History Museum of London, England.