Bear Gulch Limestone
The Bear Gulch Limestone is a fossil deposit in Montana . The approximately 325 million year old deposits from the Namurian , a time interval of the Lower Carboniferous ( Paleozoic ), give an insight into a world of cartilaginous fish and early sharks . The fossils are very well preserved. In total, the fossils of around 130 species of fish were unearthed, but also arthropods , sponges , starfish , worms , arm pods , moss animals and mollusks . Among the fish are the shark species Falcatus and Stethacanthus, armed with shoulder spines, and the Belantsea from the order of the Petalodontiformes, which has a durophage, hard-shelled food . Harpagofututor and the tadpole- like Delphyodontus are possibly relatives of the sea cats , Echinochimaera certainly . More fish are the coelacanth Allenypterus , the only two found so far genres of Guildayichthyidae , a fish family that with the recent African Flösselhechten is related (Polypteridae), the eel ray-finned Paratarrasius and the oldest lamprey Hardi Stella .
literature
- Michael J. Benton : Paleontology of the vertebrates. Translation of the 3rd English edition by Hans-Ulrich Pfretzschner. Pfeil, Munich 2007, ISBN 978-3-89937-072-0 , p. 174.
