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GEOREF RECORD

Geometric morphometric analysis of patterns of shape change in the Ordovician brachiopod Sowerbyella

Robert A. Haney, Charles E. Mitchell and Keonho Kim
Geometric morphometric analysis of patterns of shape change in the Ordovician brachiopod Sowerbyella
Palaios (April 2001) 16 (2): 115-125

Abstract

The brachiopod genus Sowerbyella is an abundant component of many Ordovician paleocommunities of the eastern United States. Five successive populations from a limited geographic region in central Kentucky were tested for the response of brachial valve size and shape to alterations in paleoenvironmental conditions. The populations span the interval from Chatfieldian to Maysvillian (M5-C3), including the majority of an Ecological-Evolutionary (EE) subunit previously described for brachiopods in this area. A marked diminution in size occurs subsequent to maximum deepening in the M5 sequence, and is persistent for the remainder of the interval sampled. Shape follows a different pattern, with similar changes occurring each time deep-water facies occur in the area. Discriminant analysis shows a clear separation between populations sampled from nearshore and offshore facies along discriminant function 1. End member populations in both nearshore and offshore populations diverge significantly on discriminant function 2 over periods of 6.5 and 3.5 my, respectively, the longer period spanning the majority of the EE subunit. This contrasts with stasis in valve shape in Devonian brachiopods over an EE subunit of similar duration, but is in accordance with previous findings of less community-level stability in Ordovician EE sub-units when compared with their Devonian counterparts.


ISSN: 0883-1351
Serial Title: Palaios
Serial Volume: 16
Serial Issue: 2
Title: Geometric morphometric analysis of patterns of shape change in the Ordovician brachiopod Sowerbyella
Affiliation: State University of New York at Buffalo, Department of Geological Sciences, Amherst, NY, United States
Pages: 115-125
Published: 200104
Text Language: English
Publisher: Society of Economic Paleontologists and Mineralogists, Tulsa, OK, United States
References: 56
Accession Number: 2002-017144
Categories: Invertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 tables, charts
N36°30'00" - N39°10'00", W89°40'00" - W82°00'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 200207
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