Tribolite Calamine Fossil

Tribolites were marine animals and rank among the most important of early animals. They belong to the same group of invertebrate animals which include crustaceans, spiders and insects of today. Our knowledge of tribolites has been gained from the study of their fossils, usually impressions left of their shells after burial in sediment which subsequently hardened into rock. Tribolites were a rounded animal, with a globose head and large eyes and probably fed on dead organic matter. They lived in Europe, N-W Africa, North and South America and China, first appearing about 542 million years ago, when they dominated the seas and became extinct about 250 million years ago.