Thesis (M.S.)--University of Iowa, 2006. / Supervisor: Jonathan M. Adrain. Includes bibliographical references (leaves 221-236).

Trilobites typical of the well known Olenellus zone of the Lower Cambrian constitute a large collection from the Eager Formation, near Cranbrook, B.C. Their classification is discussed and two new species described: Olenellus eagerensis n.sp. and Olenellus schofieldi n.sp. Since the use of certain structures in classifying olenellids has been disputed in the past, these and other less controversial features are critically examined, insofar as they apply to the genera and species present. From this study the writer assembles criteria which might be used by later workers to redefine the generic and specific positions of selected species of Olenellus and Paedeumias. / Arts, Faculty of / Geography, Department of / Graduate

Includes 5 items (fold.) in back pocket / Includes bibliographical references / 2 v. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Minerology, 1973

Includes 5 items (fold.) in back pocket / Includes bibliographical references / 2 v. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Minerology, 1973

Medial Lower Cambrian strata from continental shelf deposits of western Laurentia yield abundant, low diversity trilobite faunas. New faunas from the Cranbrook and Eager formations (southeastern British Columbia) and the upper Campito, Poleta, Harkless and Saline Valley formations (southwestern Great Basin, California and Nevada) have yielded: 33 species of Olenellina (20 new); 2 new species of Edelsteinaspidae (Redlichiina); 13 species of Corynexochida (5 new); 4 species of Ptychopariina (1 new); 1 new species of Eodiscina; 1 species of Oryctocephalidae; 1 new species of Protypidae; and 1 possible species of Cheiruroideidae. One new genus, Wannerellus, is established and tentatively assigned to the Wanneriidae. Systematic studies emphasize the importance of early ontogenetic features and ventral morphology in determining supraspecific relationships. Major changes are made to the suprageneric classification of the Olenelloidea: the Wanneriidae is recognized as a family separate from the Olenellidae; the Laudoniinae and Gabriellinae are abandoned and their type genera assigned to the Wanneriidae; the Mesonacinae is characterized as a peramorphic subfamily of the Olenellidae; and the Bristoliinae is synonymized with the Biceratopsinae (Olenellidae). The Corynexochidae is also changed in membership to include the Dorypyginae (=Ogygopsidae). Heterochrony is a major pattern of evolutionary change in Lower Cambrian trilobites. Biostratigraphic division of the medial lower Cambrian comprises 10 new subzones of 4 zones and is the first species-based trilobite zonation for Laurentia. It replaces previous genus-based zonations that are imprecise and questionable in recognition. In ascending order, the zonation includes: the Nevadia weeksi and Nevadia palmeri subzones of the Nevadia Zone; the Nevadella parvoconica and Nevadella eiicharis subzones of the Nevadella Zone; the Elliptocephala stewarti, Gabriellus poletensis and Wannerellus alcatrazensis subzones of the Elliptocephala Zone; and the Wanneria logani, Wanneria dunnae and Proliostracus buelnaensis subzones of the Olenellus transitans Zone. These zones and subzones can be correlated with other successions in western and eastern Laurentia. Biofacies differentiation of restricted shelf deposits is poorly developed in the Nevadella though Elliptocephala Zones. For this interval, the Nevadella and Wanneriid biofacies are successive biofacies of restricted shelf deposits and the Labradoria and Ekwipagetia biofacies are successive biofacies of open shelf deposits. Biofacies differentiation is well developed in the Olenellus transitans Zone, with an Olenellus Biofacies in elastics; a Wanneriid Biofacies in silty and oolitic carbonates; a Bonnia Biofacies in pure carbonates; and an Ogygopsis Biofacies in open shelf deposits. / Graduate

Trilobites collected during the past twenty years from the Morgan Creek, Point Peak, and San Saba members of the Wilberns Formation constitute the material basis for this paleontologic and statistical investigation. Eighty-nine species assigned to forty-five genera belong to zones of the upper Franconian and Trempealeauan Stages of the Upper Cambrian Croixan Series. New zonal names are proposed in the interest of a regionally applicable nomenclature. Although none of the zonal nomenclature is identical to that of the Cambrian Correlation Chart, the four zones recognized in central Texas are equivalent to the eight highest zones of the Chart. Stratigraphically lowest is the Franconian Taenicephalus zone, with a locally recognized Parabolinoides subzone at its base; this is equivalent to the Conaspis zone of the Correlation Chart. The Franconian Idahoia zone, with a locally recognized Idahoia lirae subzone at its base, is equivalent to the Ptychaspis subzone of the Ptychaspis-Prosaukia zone of the Correlation Chart. The sparsely fossiliferous Ellipsocephaloides zone corresponds to the Prosaukia subzone of the Ptychaspis-Prosaukia zone of the Chart. Almost two-thirds of the trilobite species occur in the Trempealeauan Saukia zone, which corresponds to the five highest zones of the Correlation Chart; local subzones, in ascending order, are the Saukiella pyrene subzone, the Saukiella junia subzone, the Saukiella serotina subzone, and the Corbinia apopsis subzone. The succession of ptychoparioid trilobite faunas contained within these zones make up the Ptychaspid biomere. The base of the biomere is at the base of the Taenicephalus zone; the top coincides with the lowest occurrence of the Ordovician trilobite fauna. Trilobite families that characterize the Ptychaspid biomere are the Ptychaspididae and the Parabolinoididae. Regression analyses of range data for all Saukia-zone taxa were used to compile a quantitative range chart. Differences between the quantitative chart and my intuitive range chart were not significant. Systematic descriptions include new species of Conaspis, Idiomesus, Euptychaspis, Keithiella, Saukiella, Prosaukia, Calvinella, and Westonaspis?; and one new variety of Orygmaspis. / text

Thesis (Ph.D.)--University of Iowa, 2009. / Thesis supervisor: Jonathan Mark Adrain. Includes bibliographical references (leaves 71-73).

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Bibliography : leaves 186-202. Also available online.

Trilobites and other fossils from three measured sections in the Murray Range, Pine Pass map-area, British Columbia, are described and their zonal significance is discussed. Zones represented by fossil assemblages are the Upper Olen-ellus subzone (uppermost Lower Cambrian), the Ogygopsis klotzi and Tonkinella stephensis subzones of the Bathyuriscus-Elrathina zone (upper Middle Cambrian), the upper Conaspis zone and Ptychaspis subzone of the Ptychaspis-Prosaukia zone (Upper Cambrian, Franconian Stage), the Lower or Middle Saukia zone (Trempealeau-an Stage), and Zones A, B and D of the Lower Ordovician (Canadian Series). The lower Middle Cambrian, Dresbachian and lower Franconian zones, and the Lower Ordovician Zone C, appear to be missing. Early Cambrian assemblages show some affinities with faunas of the southern hemisphere (the archaeocyathid genera Sigmocya-thus, Syringocnema and Monocyathus) and eastern Canada and the United States (species of Bonnia, Kootenia, Paedeumias and Eo-ptychoparia). However, these affinities become weaker in Middle Cambrian and later assemblages, and all the present collections are predominantly Cordilleran in character. They are considered representative of the intermediate extracratonic biofacies realm as defined by Lochman-Balk and Wilson (1958). The sections provide a further example of the transition, well-known in other parts of the Canadian Cordillera, from Lower Cambrian argillaceous and arenaceous clastic rocks to more or less argillaceous limestone and dolomite of the Middle Cambrian and later Series. Throughout Cambrian and early Ordovi-cian time the original area represented by the present sections was covered by miogeosynclinal seas which progressively encroached upon the craton. This marine transgression was interrupted at times, and the comparatively local uplift of the Peace River Arch was responsible for extreme reduction in thickness of the Middle and Upper Cambrian portions of the early Palaeozoic section. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No description available.