Fossils and their features
Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. The earliest trilobites known from the fossil record is dated to around 520 million years ago.
Orthocerases were squid-like animals and they are related to ancient ammonites as well as modern squids, octopuses, cuttlefish and nautiluses. They lived during the Jurassic period (started 201 million years ago) and Cretaceous period (ended 66 million years ago).
Mosasaurus is the extinct group of aquatic squamate reptiles. it lived from about 82 to 66 million years ago.
Ammonite fossil from Eskişehir / Turkey
Oyster fossil from Eskişehir / Turkey