Geology Faculty Publications
Document Type
Article
Publication Date
1-2009
Publication Source
Bulletin of Geosciences
Abstract
Diplograptus pristis (Hisinger, 1837) is the type species of the genus Diplograptus and name bearer for suborder Diplograptina. This species is primarily known from the Dalarne region of Sweden, where it occurs in the P. linearis Zone. D. pristis exhibits a suite of features (particularly the shape of the proximal end, the configuration of proximal spines, and the gradient in thecal form) that is uniquely shared with a number of other late Katian and earliest Hirnantian species including Glyptograptus nicholsoni Toghill, 1970; Glyptograptus posterus Koren’ & Tzai (in Apollonov et al. 1980); Orthograptus maximus Mu, 1945; and Orthograptus truncatus rarithecatus Ross & Berry, 1963. The phylogenetic affinities of the Diplograptus clade are equivocal, however. Two isolated, three-dimensionally preserved specimens of D. pristis from the Paasvere 309 core in Estonia reveal that the rhabdosome is aseptate and has a simple proximal structure comparable with a Pattern G astogeny. The pattern G astogeny, long, fully-sclerotized sicula, aseptate rhabdosome with free nema all point to its being a member of the derived orthograptids. On the other hand, the rapidly enclosed sicula and lack of antivirgellar spines together with the apertural spines on the first pair suggest archiclimacograptid affinity. Cladistic analysis supports orthograptid affinities. If these relations are correct, the Orthograptidae Mitchell, 1987, must be regarded as a junior synonym of the Diplograptidae Lapworth, 1873.
Inclusive pages
27-34
ISBN/ISSN
1214-1119
Document Version
Published Version
Copyright
Copyright © 2009, Czech Geological Survey, W. Bohemia Museum Pilsen, Palacký University Olomouc, Institute of Geology AS CR. Document is made available for download with the express permission of the publisher.
Publisher
Czech Geological Survey
Volume
84
Issue
1
Peer Reviewed
yes
Keywords
graptolite, phylogenetic systematics, biogeography, Ordovician, cladistics, Sweden, China, Scotland, Siberia, North America, Estonia
eCommons Citation
Mitchell, Charles; Maletz, Jörg; and Goldman, Daniel, "What is Diplograptus?" (2009). Geology Faculty Publications. 3.
https://ecommons.udayton.edu/geo_fac_pub/3
Comments
Permission documentation is on file.