1. A CLADID-DOMINATED EARLY MISSISSIPPIAN CRINOID AND CONODONT FAUNA FROM KERMAN PROVINCE, IRAN AND REVISION OF THE GLOSSOCRINIDS AND RHENOCRINIDS.
- Author
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Webster, G.D., Maples, C.G., Mawson, R., and Dastanpour, M.
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CRINOIDEA , *CONODONTS - Abstract
A moderately diverse crinoid fauna from the Early Mississippian, Tournaisian, part of the Bahram Formation is reported from exposures in the vicinities of Hutk and Shams Abad, north of Kerman in southeastern Iran. Conodonts from the crinoid-bearing beds represent two faunas and indicate an age of Upper Siphonodella crenulata Biozone to Gnathodus typicus Biozone. Recognition of a Tournaisian age for this part of the Bahram Formation revises the previously assigned Famennian age and indicates that Famennian strata are much thinner, if present, in southeastern Iran. The fauna occurs in thin-bedded marls and limestones at the top of a shaley slope-forming sequence that grades upward into resistant cliff-forming limestones. Most crinoid specimens are crowns (many retaining part of the proximal stem) that have been flattened by compaction. At the genus level the crinoids include five camerates, three cladid dendrocrinids, ten other cladids, three flexibles, and one articulate. In addition, loose arm fragments and occasional cup fragments are common, along with abundant pluricolumnals and columnals in the fauna. Dominance of cladids over camerates probably reflects the argillaceous sediment in the mixed carbonate/ siliciclastic platform environment of the fauna. This is the most diverse Tournaisian fauna reported from the northern margin of Gondwana and represents an equatorial fauna living at approximately 20°S latitude. Stronger affinities are with North American and European crinoid faunas than with Chinese and Australian faunas. Shallow-shelf conodonts from the crinoid-bearing beds are dominated by species of Polygnathus. Palaeoniscoid fish remains and shark teeth from the same beds support a shallow-shelf environment. New taxa proposed are Dichocrinus shamsensis new species; D. labyrinthus new species; Springeracrocrinus conicus new species; Atelestocrinus hutkensis new species; Zangucrinus abadensis new genus and species; Glossocrinacea new superfamily;... [ABSTRACT FROM AUTHOR]
- Published
- 2003
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