http://worldcat.org/entity/work/id/4480671

Echinodermata of the Middle Ordovician Lebanon Limestone, central Tennessee

Representatives of six classes of echinoderms, the Crinoidea, Paracrinoidea, Rhombifera, Asteroidea, Edrioasteroidea, and Echinoidea are present in the Middle Ordovician Lebanon Limestone of central Tennessee. Crinoids are the most abundant and diverse class present and include the following new taxa: Tornatilicrinidae, new family; Tryssocriniae, new subfamily; Tornatilicrinus, Tryssocrinus, and Gustabilicrinus, all new genera; Cleocrinus springeri, Reteocrinus polki, R. cariabilicaulis, R. fenestratus, Grustabilicrinus plektanikaulos, G. latomium, Archaeocrinus snyderi, Abludoglyptocrinus gregatus, Tornatilicrinus longicaudis, ?Anomalocrinus antiquus, Tryssocrinus endotomitus, Doliocrinus monilicaulis, Porocrinus lebanonensis, and Hybocrinus bilateralis, all new species. Reteocrinus Billings, 1859, is revised and Trakocrinus Kolata, 1975, is suppressed and reassigned to Retocrinus. Columbicrinus crassus Ulrich, 1925, is redescribed based on more complete new material and Praecursoricrinus Frest, Strimple, and McGinnish, 1979, is suppressed and reassigned to Columbicrinus Ulrich, 1925. Of other echinoderms, Oklahomacystis trigonis (Paracrinoidea); Praepleurocystis ranaformis, Amecystis nanus, and Tanaocystis sprinklei (Rhombifera); Schuchertia darwini (Asteroidea); Unibothriocidaris kieri and Bothriocidaris vulcani (Echinoidea) are new. Previously unknown features include crinoid and paracrinoid columns and holdfasts and a partial peristome of Unibothriocidaris Kier, 1982. Echinoderms indicate a middle to late Blackriveran age for the Lebanon, an interpretation in approximate agreement with ages based on conodonts and brachiopods. Other major faunal groups in the Lebanon are brachiopods, bryozoans, and arthropods. Dominant lithologies include pellet biocalarenites, brachiopod, bryozoan, echinoderm biocalcirudites, calcisiltites, and calcilutites. Paleontologic and sedimentologic evidence indicates the Lebanon was deposited in a moderate-energy normal marine shelf environment ranging from mean low water to 20 to 30 m in depth.

Open All Close All