page_title: Paleobiota of the Posidonia Shale
section_title: Asterozoa
hierarchical_section_title: Paleobiota of the Posidonia Shale / Invertebrata / Echinodermata / Asterozoa
caption_attribution_description: English: Title: Bulletin Identifier: bulletin21stat (find matches) Year: 1904- (1900s) Authors: State Geological and Natural History Survey of Connecticut Subjects: Geology -- Connecticut; Animals -- Connecticut; Plants -- Connecticut Publisher: (Hartford)&#160;: The Survey Contributing Library: New York Botanical Garden, LuEsther T. Mertz Library Digitizing Sponsor: The LuEsther T Mertz Library, the New York Botanical Garden View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: ' Text Appearing After Image: Plate XVI, Daisy Brittle-star, Ophiopholis aculeata. ( One and one-half times natural size.) Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.
context_page_description: The Posidonia Shale or Posidonienschiefer Formation is a geological formation of southwestern Germany, northern Switzerland, western Czech Republic, northwestern Austria, southeast Luxembourg and the Netherlands, that spans about 3 million years during the Early Jurassic period. It is known for its detailed fossils, especially sea fauna, listed below. Composed mostly by black shale, the formation is a Lagerstätte, where fossils show exceptional preservation, with a thickness that varies from about 1 m to about 40 m on the Rhine level, being on the main quarry at Holzmaden between 5 and 14 m. Some of the preserved material has been transformed into fossil hydrocarbon Jet, specially wood remains, used for jewelry. The exceptional preservation seen on the Posidonia Shale has been studied since the late 1800s, finding that a cocktail of chemical and environmental factors let to such an impressive conservation of the marine fauna. The most common theory is the changes on the oxygen level, where the different anoxic events of the Toarcian left oxygen-depleted bottom waters, with the biota dying and falling to the bottom without any predator able to eat the dead bodies.
caption: Modern Specimen
exif: {}