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GEOREF RECORD

Paleoecologic assessment of an edrioasteroid (Echinodermata)-encrusted hardground from the Upper Ordovician (Maysvillian) Bellevue Member, Maysville, Kentucky

Rene A. Shroat-Lewis, Michael L. McKinney, Carlton E. Brett, David L. Meyer and Colin D. Sumrall
Paleoecologic assessment of an edrioasteroid (Echinodermata)-encrusted hardground from the Upper Ordovician (Maysvillian) Bellevue Member, Maysville, Kentucky
Palaios (August 2011) 26 (8): 470-483

Abstract

Since population studies are most reliable when applied to census assemblages, edrioasteroid paleoecology can best be understood by examining catastrophically buried obrution communities. This paleoecologic study examines a carbonate hardground surface encrusted with four species of isorophid edrioasteroids: Curvitriordo stecki, Carneyella ulrichi, Carneyella pilea, and Streptaster vorticellatus. Analysis of edrioasteroid diameters, a proxy for age, shows a bimodal distribution for Curvitriordo stecki, suggesting a hiatus in recruitment or multiple spatfalls. Low juvenile mortality may explain a left-skewed distribution among individuals of Carneyella ulrichi. Lack of juvenile individuals of S. vorticellatus suggests that this population matured from a single spatfall; there were too few specimens of C. pilea for analysis. Edrioasteroids on this surface exhibit no preferred ambulacral orientation. Spatial analysis (SA) shows an inter-specific clustered distribution at several spatial scales. Intraspecific SA indicates a clustered distribution for Curvitriordo stecki and Carneyella ulrichi; there were too few specimens of S. vorticellatus and C. pilea for analysis. Examination of inter- and intraspecific edrioasteroid taphonomy reveals that thecal collapse, disarticulated cover plates, and disarticulated interambulacral plates occur in nearly half of the population, suggesting brief post-mortem exposure on the paleoseafloor without protection of sediment cover. Individuals of S. vorticellatus suffered thecal collapse, yet all plates and ambulacra remained intact, suggesting that robust thecal elements may inhibit thecal disarticulation.


ISSN: 0883-1351
Serial Title: Palaios
Serial Volume: 26
Serial Issue: 8
Title: Paleoecologic assessment of an edrioasteroid (Echinodermata)-encrusted hardground from the Upper Ordovician (Maysvillian) Bellevue Member, Maysville, Kentucky
Affiliation: University of Tennessee Knoxville, Knoxville, TN, United States
Pages: 470-483
Published: 201108
Text Language: English
Publisher: Society for Sedimentary Geology, Tulsa, OK, United States
References: 65
Accession Number: 2011-076489
Categories: Invertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: NSF grants EAR-0745918 and DGE-0538420
Illustration Description: illus. incl. 2 tables, sketch map
N38°38'60" - N38°38'60", W83°46'60" - W83°46'60"
Secondary Affiliation: University of Cincinnati, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States
Update Code: 201142
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