Description: Specimen: PTYCHOCARPUS UNITUSLocality: MAZON CREEK, Illinois USAThe Mazon Creek fossils are found in the Upper Carboniferous Francis Creek Shale; the type locality is the Mazon River (or Mazon Creek), a tributary of the Illinois River near Morris, Grundy County, Illinois. The 25 to 30 meters of shale were formed approximately 309 million years ago, during the Pennsylvanian period. The fossiliferous concretions are usually found within the thickest deposits of Francis Creek. The concretions occur in localized deposits within the silty to sandy mudstones, in the lower four meters of the formation. The paleoecosystem is believed to be a large river delta system, deposited by at least one major river system flowing from the northeast. The sediments are believed to derive from the Appalachian orogeny events. The delta had a tropical climate, a result of the area being within 10° north latitude of the equator during the Pennsylvanian. The remains of plants and animals were rapidly buried by the sediment deposited in the deltaic system. Bacterial decomposition of the remains produced carbon dioxide that combined with dissolved iron from the groundwater. This process formed siderite in the sediments surrounding the remains, forming detailed casts of their structure. Lithification of the sediments formed protective nodules of ironstone around the now fossilized remains. This mode of preservation is known as authigenic mineralisation.The Mazon Creek flora comprises over 400 species from at least 130 genera. However, the true number of species is difficult to determine. Mazon Creek flora includes: lycopsids, related to modern club moss, with arborescent forms named Lepidophloios, Sigillaria and Lepidodendron, and herbaceous forms called Lycopodites and Cormophyton; spenopsids like Calamites a tree-like horsetail relative, with common foliage names of Annularia and Asterophyllites, and a vine-like form called Sphenophyllum; Pteridophyta as marattitalean tree ferns and Filicales and Zygopteridales understory ferns, with common foliage names of Pecopteris, Acitheca and Lobatopteris; pteridosperms, also known as seed ferns, an extinct group of plants that grew both as trees and smaller shrubs, with features like pinnated leaves similar to true ferns, but reproduced by seeds instead of spores; they had common foliage names Mariopteris, Alethopteris, Odontopteris, Neuropteris, Laveineopteris and Macroneuropteris; extinct gymnosperm Cordaites, believed to be closely related to and sharing many features with modern conifers. This is a wonderful 2 Piece Fossil with both Positive and Negative halves.Photographed on a 1 INCH Scale board to show relative size - This is the fossil you will receive. SEE PHOTOS FOR WHAT YOU WILL BE RECEIVING☆☆ See my other Mazon Creek Fossils ☆☆Specimens of fossils that are in my other auctions include: SPHENOPHYLUM, CALAMITES, ANNULARIA, PECOPTERIS, PTYCHOCARPUS UNITUS, NEUROPTERIS, ALETHOPTERIS, ASTEROPHYLLITEThese 300 Million Year old fossils were self collected in the 1960's. PLEASE SEE MY OTHER AUCTIONS FOR A WIDE VARIETY OF CRYSTALS, MINERALS & FOSSILSPayment terms:PAYPALNo International ShippingShips only to lower 48 Continental StatesNo Shipping to APO / FPOPlease ask questions if you need more information and I will be glad to help in any way I can.
Price: 9.02 USD
Location: Grovetown, Georgia
End Time: 2024-02-20T17:33:37.000Z
Shipping Cost: 5.25 USD
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All returns accepted: ReturnsNotAccepted
Modified Item: No
