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GEOREF RECORD

Diploporite (Echinodermata, Blastozoa) thecal attachment structures from the Silurian of southeastern Indiana

James R. Thomka and Carlton E. Brett
Diploporite (Echinodermata, Blastozoa) thecal attachment structures from the Silurian of southeastern Indiana
Journal of Paleontology (January 2014) 88 (1): 179-186

Abstract

Taxonomic descriptions of diploporites from the middle Silurian of eastern Laurentia have focused nearly entirely on thecal plating, with minimal description or figuring of attachment structures. A recently discovered hardground surface within the Wenlock-age (Sheinwoodian) Massie Formation that is encrusted by numerous well-preserved pelmatozoan holdfasts, including structures identifiable as diploporite thecal attachments, provides an opportunity to document the morphology of these rarely described structures. Moderately thin-walled structures with a parabolic, depressed central area composed of seven distinct marginal plates with prominent pores appear to represent thecal attachments of the broad-based trematocystinid holocystitid Paulicystis. Thick-walled, steep-sided structures composed of five to seven fused or partially fused plates with less prominent pores, a deep stelar depression, and radiating canals appear to represent thecal attachments of undetermined, possibly holocystinid or pentacystinid holocystitids. All diploporite holdfasts are cemented to fine-grained, well-sorted skeletal substrates on elevated crests of the hardground surface, but are not found on microbioherms.


ISSN: 0022-3360
EISSN: 1937-2337
Coden: JPALAZ
Serial Title: Journal of Paleontology
Serial Volume: 88
Serial Issue: 1
Title: Diploporite (Echinodermata, Blastozoa) thecal attachment structures from the Silurian of southeastern Indiana
Affiliation: University of Cincinnati, Department of Geology, Cincinnati, OH, United States
Pages: 179-186
Published: 201401
Text Language: English
Publisher: Paleontological Society, Lawrence, KS, United States
References: 57
Accession Number: 2014-012973
Categories: Invertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: IGCP Project No. 591
Illustration Description: illus. incl. strat. col., geol. sketch map
N39°13'00" - N39°13'00", W85°19'00" - W85°19'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, The Paleontological Society. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201409
Program Name: IGCPInternational Geological Correlation Programme
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