The original aragonite internal shell dissolved and was replaced by opal in these belemnite fossils. They existed the Cretaceous Period. ...

Picture is of a Benthosuchus sushkini amphibian skull fossil. It dates to the Triassic Period. Fossil found in Scharzhenga River of Vachn...

Image is of Glossopteris browniana fossil leaves. Plant existed in the Permian Period. They were found in Silewada India. Displayed at Nat...