Topic
Wanneria
About: Wanneria is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 35 citations.
Papers
TL;DR: Theokritoff et al. as mentioned in this paper reviewed and modified a model of Early Cambrian trilobite biogeography in the North Atlantic region and interpreted the faunas of the Bastion Formation of East Greenland and of the Devil's Cove Limestone of northern Newfoundland.
Abstract: A model of Early Cambrian trilobite biogeography in the North Atlantic region (Theokritoff 1979. Lethaia 12, 281–295) is reviewed and modified in the light of new data. The presence of Wanneria in conglomerates bearing the Elliptocephala asaphoides fauna strengthens correlation of the E. asaphoides fauna as well as, by implication, the upper part of the Calluvia Zone with the middle part of the Bonnia-Olenellus Zone. The faunas of the Bastion Formation of East Greenland and of the Devil's Cove Limestone of northern Newfoundland are reinterpreted as shelf faunas. Additional occurrences of Archaeocyatha are noted in Spain and northwest Scotland but reports of Archaeocyatha in northern Norway and East Germany are not authenticated. Neither Salterella nor ‘Volborthella’ are now recognized as characteristic of any trilobite province. Although Ordovician acritarch provinces show congruence with trilobite provinces, available data on Early Cambrian plankton are not sufficient to support algal provincialism. Interpretation of the geological record suggests that the Early Cambrian lapetus Ocean was stratified with a well-mixed oxygenated zone overlying a phosphate-rich oxygen minimum zone and that the Elliptocephala asaphoides fauna should be reinterpreted as a warm-water fauna.
33 citations
TL;DR: Taxonomic and morphological diversity within the formerly monotypic Lochmanolenellus is greatly expanded by the description of three new species plus several in open nomenclature, and a comparative study of the ontogenetic development of the cephalon of each of the new species to other olenelloids is strongly suggested.
Abstract: The olenelloid trilobite genus Laudonia Harrington, 1956 was thought to occur widely along the Cordilleran margin of Laurentia in lowermost Dyeran strata (Cambrian Series 2). However, supposed occurrences in the Rosella Formation (Cassiar Mountains, northern British Columbia), the Mural Formation (Cariboo Mountains, east-central British Columbia) and the Poleta Formation (Nevada)—re-examined, morphometrically analyzed, and fully documented for the first time herein—are found to actually represent occurrences of species of Lochmanolenellus Lieberman, 1998. This revision results in the restriction of Laudonia to two species— Laudonia bispinata Harrington, 1956 and Laudonia amputata Fr itz, 1992—that are known only from the Mural Formation of the Mount Robson area (Canadian Rocky Mountains, Alberta/British Columbia) and are therefore of little biostratigraphic utility. Conversely, taxonomic and morphological diversity within the formerly monotypic Lochmanolenellus is greatly expanded by the description of three new species plus several in open nomenclature. The new species form a stratigraphic succession comprising Lochmanolenellus pentagonalis n. sp. (oldest) followed by Lochmanolenellus subquadratus n. sp. and then Lochmanolenellus trapezoidalis n. sp. (youngest) in the Cassiar Mountains and in Nevada, and thus seem to offer some biostratigra phic utility. Lochmanolenellus primus (Lochman in Cooper et al ., 1952), the genotype, occurs only in the Puerto Blanco Formation (Caborca area, Sonora). These new data, combined with a comparative study of the ontogenetic development of the cephalon of each of the new species of Lochmanolenellus to other olenelloids, strongly suggest that Lochmanolenellus is closely related to “wanneriid” olenelloids such as Wanneria Walcott, 1910 and Elliptocephala Emmons, 1844 rather than to biceratopsid olenelloids.
14 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2014 | 1 |
| 1985 | 1 |