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Anchorage, AK, United States

Rasmussen C.M.O.,Copenhagen University | Harper D.A.T.,Durham University | Blodgett R.B.,2821 Kingfisher Drive
Fossils and Strata | Year: 2012

A silicified brachiopod fauna from the White Mountain area, west-central Alaska is catalogued and interpreted within a palaeoecological and biogeographical context. This area is situated within the Nixon Fork Subterrane of the Farewell Terrane; its origin and timing of final docking with Laurentia has been much debated. The current study adds new faunal data to the debate. The fauna was collected from three localities; a main locality in the upper Darriwilian - lower Sandbian and two additional middle-upper Katian localities. All three localities contain a predominantly deep-water autochthonous fauna that was mixed with an allochthonous fauna as a result of down-slope movement of turbidity currents at the shelf-break to slope transition. Deposition of the autochthonous fauna was within Benthic Assemblage zones 4-5, possibly shallower in the Katian localities. The three localities comprise a very diverse fauna consisting of nearly 100 taxa. Of these the genera Callositella cheeneetnukensis, Duolobella sandiae, Palaeowingella farewellensis and Transridgeia costata are new. In addition nine new species are described: Anisopleurella tricostata, Christiania aseptata, Craspedelia potterella, Gelidorthis perisiberiaensis, Leptaena (Septomena) alaskensis, Oanduporella kuskokwimensis, Ptychoglyptus alaensis, Sowerbyella (Rugosowerbyella) praecursor and Sowerbyella (S.) rectangularis. Furthermore, Leptellina pulchra and Strophomena planobesa are revised and assigned to Anoptambonites and Tetraphalerella, respectively. The large number of new taxa indicates an endemic fauna that has affinities with the cosmopolitan deep-water faunas of this time interval. However, the fauna demonstrates great similarity with those from the Eastern Klamath Terrane, northern California and the Jones Ridge area on the Alaska - Yukon border, as well as faunas of Eastern USA. As the Laurentian affinities are all based on deep-water taxa, it may not indicate particularly close faunal links between the Farewell Terrane and Laurentia. More noteworthy, several taxa indicate faunal exchange, in some cases at the species level, between peri-Laurentian terranes such as the Midland Valley Terrane and the palaeocontinents of Siberia and even Baltica. Notably the link to Siberia is strengthened by two cluster analyses conducted for the studied localities, indicating that the Farewell Terrane probably is derived from Siberia but by the Late Ordovician was in a sufficiently isolated position to develop a whole suite of endemic taxa. © 2012 The Lethaia Foundation.

Ebbestad J.R.,Uppsala University | Fryda J.,Czech Geological Survey | Wagner P.J.,Smithsonian Institution | Horny R.J.,National Museum | And 8 more authors.
Geological Society Memoir | Year: 2013

The biogeographical distribution of Ordovician and Silurian gastropods, monoplacophorans and mimospirids has been analysed on a generic level. The dataset contains 334 genera and 2769 species, yielding 1231 records of genera with 2274 occurrences worldwide. There is a bias towards eastern Laurentia, Baltica and Perunica records. Some 53.1% of the records are Ordovician. The study demonstrates that these molluscs are well suited to being used to improve understanding of Ordovician and Silurian biogeographical provinciality. Specific points are that: a Lower Ordovician assemblage is evident in Laurentia; the fauna of the Argentinean Precordillera is Laurentian until the Darriwilian, when taxa are shared with North China; Late Silurian gastropods from the Alexander terrane (SE Alaska) are unknown in Laurentia, but support a rift origin of this terrane from NE Siberia; Perunica, Ibero-Armorica and Morocco cluster together throughout the Ordovician but Perunica and Morocco are closer; Darriwilian-Sandbian deep-water Bohemian taxa occur in Baltica; a Laurentian-Baltica proximity is unsupported until the Silurian; Siberia clusters with North China and eastern Laurentia during the Tremadocian-Darriwilian; during the Gorstian-Pridoli Siberia clusters with the Farewell and Alexander terranes; North China may have been close to Laurentia and the Argentinean margin of Gondwana; and the affinity of Tarim taxa is problematic.

Blodgett R.B.,2821 Kingfisher Drive | Rohr D.M.,Sul Ross State University | Fryda J.,Czech Geological Survey | Lenz A.C.,University of Western Ontario
Memoirs of the Association of Australasian Palaeontologists | Year: 2011

A new Pragian gastropod species, Stenoloron (Stenoloron) boucoti, is established from the richly diverse Lower Devonian gastropod fauna of the Road River Formation in the Royal Creek area, Yukon Territory. This new species is a common element amongst Pragian gastropods from the Royal Creek fauna, and is also noted in coeval strata of the Delorme Formation, Northwest Territories, Canada. Both occurrences are within the Western Canada Province previously established by us for Lower Devonian gastropods of this area. This is the second occurrence of this Old World Realm genus and subgenus in North America. The only prior North American record was Stenoloron (Stenoloron) minor Blodgett & Johnson, 1992, from Eifelian (early Middle Devonian) age strata of the Denay Limestone of central Nevada.

Baranov V.V.,Russian Academy of Sciences | Blodgett R.B.,2821 Kingfisher Drive
Paleontological Journal | Year: 2016

New strophomenid and rhynchonellid (Brachiopoda) taxa are described from the Lower Pragian (Soda Creek Limestone) of west-central Alaska: Harperoides gen. nov. with type species H. alaskensis sp. nov. (subfamily Mesodouvillinae Harper et Boucot) and Pedderia gen. nov. with type species P. fragosa sp. nov. (family Pygmaellidae Baranov). © 2016, Pleiades Publishing, Ltd.

Baranov V.V.,Russian Academy of Sciences | Blodgett R.B.,2821 Kingfisher Drive
Bulletin of Geosciences | Year: 2011

The terebratulidine Gonella boucoti gen. et sp. nov. is described from Pragian and Emsian strata of the Selennyakh Range (Northeast Asia). Color patterns are found in both valves, consisting of six radial, dark reddish-brown color bands which begin at the beak, and uniformly expand anteriorly to the anterior margins of the valves. The latter feature, in combination with the character of accompanying megafauna, clearly testify to the presence of a tropical-subtropical climate for this region.

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