 | Texas Pennsylvanian FossilsDedicated to the Study of Pennsylvanian Fossils, Sponsored by Members of the Dallas Paleontological Society |
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Brachiopods - Inarticulate | Brachiopods are a diverse group of marine invertebrates that arose in the Cambrian, were a dominant fauna in the Paleozoic, and still exist today, but in a much-reduced number and diversity. They are filter feeders that live within a pair of hinged shells and are usually attached to the substrate by a fleshy stalk called a pedicle. Although outwardly similar to molluscan bivalves, they have a different internal anatomy, and their shells are differentiated most easily by a difference in symmetry. Most brachiopods, especially in the Paleozoic, have a hinge structure which hold the shells together consisting of teeth and sockets (articulates) but another group do not have these structures, and the two shells are just held together by interior muscles (inarticulates). Inarticulates also have a shell composed of calcium phosphate and chitinous matter while articulate shells are almost always composed of calcium carbonate. In the Finis, there are four known genera of inarticulate brachiopod, and they are generally small and usually found attached to other brachiopods or the substrate. They usually lack much ornamentation and often have a shiny black appearance. None of the genera are especially common, but they can be found with diligent searching. ----------------------------------------------------------------------------------------------------------------------------------------- Scroll through images or click to enlarge. Fossils are in alphabetical order by Genus.Collections are from Mike DeBrock (MD), Josh Hanley (JH), Dr. Peter Holterhoff (PH), Mark McKinzie (MM), John McLeod (JM), ), Dr. Ben Neuman (BN), Bob Williams (BW), Sveta Earnest (SE), and Rodney Wise (RW). All scales are shown in millimeters unless otherwise noted. |
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Images | Taxonomy/Stratigraphy/ | Images | Taxonomy/Stratigraphy/ |
Kingdom: Animalia Phylum: Brachipoda Class: Lingulata Order: Lingulida Family: Lingulidae Genus: Lingula Species: L. carbaronia Finis Shale, Graham Formation Lost Creek Dam, Jacksboro, TX Collection: MM | Kingdom: Animalia Phylum: Brachipoda Class: Lingulata Order: Lingulida Family: Discinidae Genus: Orbiculoidia Species: O. missouriensis Finis Shale, Graham Formation Lost Creek Dam, Jacksboro, TX Collection: MM |
Kingdom: Animalia Phylum: Brachipoda Class: Craniata Order: Craniida Family: Craniidae Genus: Petrocrania Species: P. modesta Finis Shale, Graham Formation Lost Creek Dam, Jacksboro, TX Collection: MM | Kingdom: Animalia Phylum: Brachipoda Class: Lingulata Order: Lingulida Family: Obolidae Genus: Trigonoglossa Species: T. nebrascensis Finis Shale, Graham Formation Lost Creek Dam, Jacksboro, TX Collection: MM, SE |
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