Results 201 to 210 of about 2,442 (222)

Evolutionary radiations In the Trilobita

1991
Abstract Radiations have been understood in several ways; the trilobites have a good fossil record which can be used to examine these different usages. Supposed radiations in the sense of accelerated cladogenesis (especially involving higher taxa) are discussed at two important times: the basal Cambrian radiation; and the basal ...
R A Fortey, R M Owens
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Ontogeny and relationships of Trinucleoidea (Trilobita)

Journal of Paleontology, 1994
Protaspides and later growth stages are described and discussed for the Ordovician trinucleid trilobite Cryptolithus tesselatus Green and the raphiophorid Lonchodomas chaziensis Shaw. A small triangular rostral plate is described for a single protaspid instar in both Cryptolithus and Lonchodomas.
Brian D. E. Chatterton, Gregory D. Edgecombe, Stephen E. Speyer, Allen S. Hunt, Richard A. Fortey   +4 more
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Onnia (Trilobita) from Venezuela

1954
(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
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LICHIDAE (TRILOBITA): MORPHOLOGY AND CLASSIFICATION

Journal of Paleontology, 2002
Abstract Morphology is reviewed with special reference to the doublure and thoracic characters; a reconstruction of Richterarges aquilonius is used to suggest possible lichid anatomy. The relatively large hypostome and wide doublure, and the thorax with, or without, the strongly convex posterior pleural bands characterize lichids, in addition to the ...
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Trilobita

2007
Los trilobites fueron artrópodos marinos paleozoicos, provistos de una cutícula dorsal mineralizada (exoesqueleto) y fosilizable, la que permitió que tengan gran representación en el registro fósil. Desde que aparecen en el Cámbrico Temprano, su diversidad alcanzó valores elevados en el Cámbrico Tardío-Ordovícico, para decrecer durante el Silúrico ...
Tortello, Marcelo Franco, Waisfeld, Beatriz G., Vaccari, Norberto E.   +2 more
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Thysanopeltidae (Trilobita) from the British Devonian

1966
(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
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Evolution and classification of some Ordovician Calymenina (Trilobita)

Geological Magazine, 1980
SummaryThe classification of the generaPlaesiacomiaHawle & Corda, 1847,KerfornellaHenry, 1976,ColpocorypheNovák in Perner, 1918,SalterocorypheHammann, 1977 andNeseuretusHicks, 1873, is discussed.PlaesiacomiaandKerfornellaare attributed to the Homalonotidae (sub family Kerfornellinae nov.), whileColpocoryphe, Salterocoryphe, andNeseuretusare ...
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Silurian Encrinurinae (Trilobita) from the central United States

Journal of Paleontology, 1992
Silurian (Llandovery–Ludlow) Encrinurinae from Wisconsin, Indiana, and Illinois include species ofBalizomaHolloway, 1980,CurriellaLamont, 1978,DistyraxLane, 1988,EncrinurusEmmrich, 1844,MackenziurusEdgecombe and Chatterton, 1990a, andNucleurusRamsköld, 1986.Mackenziurus lauriaen. sp.
Kenneth C. Gass, Gregory D. Edgecombe, Lars Ramsköld, Donald G. Mikulic, Rodney Watkins   +4 more
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Ecdysis inFlexicalymene meeki(Trilobita)

Journal of Paleontology, 1993
The ecdysial style ofFlexicalymene meeki(Foerste) from the Upper Ordovician of the Cincinnati arch (Ohio) is best characterized by a spectrum of configurations. Recurring patterns of displaced tergites and points of disarticulation indicate differential susceptibility of the exoskeleton to disarticulation during ecdysis. Specimens identified as exuviae
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Notes on Archikainella and Paraacidaspis (Trilobita)

1990
The type material of Chinese Upper Cambrian eoacidaspidid trilobites is here reviewed. Belovia, Eoacidaspis, Paraacidaspis and Archikainella are assigned to the family Eoacidaspididae. Paraacidaspis is a valid genus. Metaacidaspis Qiu, 1983, is a junior synonym of Archikainella Liu, 1982.
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