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Parablastoid holdfasts from the Lower Ordovician of South Wales
Author(s) -
Cope John C. W.,
Donovan Stephen K.
Publication year - 2005
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.1013
Subject(s) - lithification , geology , paleontology , ordovician , reticulate , stage (stratigraphy) , echinoderm , thickening , sediment , chemistry , polymer science
Problematical discoid fossils from the Lower Arenig (Moridunian Stage) of the Llangynog Inlier, South Wales, are interpreted as parablastoid holdfasts. They constitute the first record of holdfasts in this rare echinoderm class. The lower surface has a radial ribbed structure, in contrast to the concentric, reticulate structure of the upper surface. The substrate for attachment was not lithified and may instead have been sediment stabilized by microbial mats. An associated pluricolumnal indicates that the parablastoid column was homeomorphic. Copyright © 2005 John Wiley & Sons, Ltd.