Results 151 to 160 of about 900 (192)

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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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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Revision of Eurudagnostus Lermontova (Agnostida, ?Trilobita)

Paleontological Journal, 2014
The validity of Eurudagnostus Lermontova, 1951 was confirmed by reexamination of the collection from the Boshe-Kul’ core. The diagnoses of genera of Agnostidae were reviewed, and Eurudagnostus falls well within the concept of the family Agnostidae. The diagnostic features of Eurudagnostus include a delicate border furrows, the transglabellar furrow ...
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Ordovician Pterygometopidae (Trilobita) of North America

Canadian Journal of Earth Sciences, 1982
Pterygometopidae are common trilobites in Middle and Upper Ordovician rocks of North America, northern Europe, and Siberia and they have considerable biogeographic usefulness. The subfamilies Pterygometopinae and Chasmopinae characterize Baltica, the Eomonorachinae characterizes Laurentia, and the Monorakinae characterizes Siberia.
Rolf Ludvigsen, Brian D. E. Chatterton
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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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FIRST CARBONIFEROUS PROTASPID LARVAE (TRILOBITA)

Journal of Paleontology, 2005
Abstract The recovery of well-preserved silicified larvae from the early Tournaisian of Montagne Noire, southern France, allows the first description of the early ontogeny of proetoid trilobites, survivors of the end-Devonian Hangenberg extinction event.
RUDY LEROSEY-AUBRIL, RAIMUND FEIST
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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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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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A review of Ordovician agnostid genera (Trilobita)

Transactions of the Royal Society of Edinburgh: Earth Sciences, 1996
ABSTRACTThe definition and scope of Ordovician genera of agnostid trilobites are discussed, and the generic affiliation of Ordovician species and well-illustrated material referred to in open nomenclature is assessed. Some 198 Ordovician species plus 25 species of uncertain latest Cambrian/earliest Ordovician age are enumerated, representing 24 genera ...
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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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