Middle Devonian brachiopods from the Bird Fiord Formation, Arctic Canada

2003 ◽  
Vol 77 (2) ◽  
pp. 243-266 ◽  
Author(s):  
Li Rong-Yu ◽  
Brian Jones
Keyword(s):  
New Species ◽  
Middle Devonian ◽  
Canadian Arctic ◽  
Ellesmere Island ◽  
The Arctic ◽  
Arctic Canada ◽  
Early Devonian ◽  
Delta Plain ◽  
The Cross

The late Early Devonian to Middle Devonian Bird Fiord Formation, which is up to 900 m thick, is exposed along an extensive outcrop belt from stretches from Ellesmere Island to Bathurst Island in Arctic Canada. This formation, which encompasses sediments that accumulated in sabkha, deltaic, and shelf settings, is divided into six members. The Blubber Point, Baad Fiord, Norwegian Bay, and Cardigan Strait members, which include sediments that formed on an open marine shelf, are characterized by a diverse biota of brachiopods, mollusks, corals, trilobites, and sponges. The Cross Bay and Grise Fiord members, which encompass sediments that formed in a sabkha and delta plain settings, respectively, are generally devoid of fossils.A collection of 47,026 brachiopods, which came from 140 collections made at 34 locations throughout the outcrop belt of the Bird Fiord Formation, contains 22 species of brachiopods that belong to 21 genera. This biota includes six new species: Gypidula mega, Spinatrypa (Isospinatrypa) parva, Desquamatia (Independatrypa) fortis, Nucleospira stelcki, Warrenella grinnellensis, and Cranaena briceae. Four genera (Arcticastrophia Li and Jones, 2002, Borealistrophia Li and Jones, 2002, Grinnellathyris Li and Jones, 2002, and Costacranaena Johnson and Perry, 1976) and 16 species of brachiopods are endemic to the Arctic Canada. Conversely, the fauna also includes European elements such as Nucleospira lens (Schnur), Spinatrypa (Isospinatrypa), and Warrenella. These taxa may indicate that there was some communication between the Canadian Arctic and Europe during Middle Devonian.

Atrypoidea species from the Canadian Arctic islands

1981 ◽  
Vol 18 (10) ◽  
pp. 1539-1561 ◽  
Author(s):  
Brian Jones
Keyword(s):  
New Species ◽  
Morphological Analysis ◽  
Canadian Arctic ◽  
Ellesmere Island ◽  
Evolutionary Trends ◽  
Arctic Canada ◽  
Separate Species ◽  
Devon Island ◽  
Upper Silurian ◽  
The Relationship

Species of Atrypoidea have the potential of being biostratigraphically useful for the Upper Silurian strata of Arctic Canada. Critical to any biostratigraphic scheme is the relationship between A. phoca (Salter, 1852) and A. scheii (Holtedahl, 1914) since there is disagreement as to whether these species are synonymous, or distinct and stratigraphically separate species. Detailed morphological analysis of topotype A. scheii from Goose Fiord, Ellesmere Island shows that it falls within the range of morphological variation displayed by topotype A. phoca from Cape Riley, Devon Island. Consequently, A. scheii is maintained as a synonym of A. phoca.Other new species that may prove to be biostratigraphically useful include Atrypoidea gigantus n.sp. from an unnamed formation at Goose Fiord and A. netserki n.sp. from member C of the Read Bay Formation on Beechey Island. Atrypoidea gigantus, the largest species of Atrypoidea so far reported from Arctic Canada, is closely related to Atrypoidea foxi (Jones, 1974). Atrypoidea netserki is morphologically closest to A. phoca.Although the Atrypoidea sequences in the Ludlovian and Pridolian strata of Arctic Canada are now better known it is still difficult to delineate exact evolutionary trends, possibly because the various species have a facies- as well as a time-controlled distribution.

Early Devonian graptolites and graptolite biostratigraphy, Arctic Islands, Canada

2013 ◽  
Vol 50 (11) ◽  
pp. 1097-1115 ◽  
Author(s):  
Alfred C. Lenz
Keyword(s):  
New Species ◽  
Canadian Arctic ◽  
The Arctic ◽  
Early Devonian ◽  
Lower Emsian ◽  
The World

The Early Devonian graptolite fauna of the Arctic Islands comprises the highest species content (17 species) in the world. In spite of this richness, no new species have been recognized; instead already-existing species, scattered around the then-known continents, suggest that relatively complete cosmopolitanism held sway for graptolites. Canadian Arctic biozonation is very similar to schemes elsewhere, consisting of the uniformis and hercynicus biozones in the Lochkovian, falcarius in the lower Pragian, and an expanded yukonensis Biozone in the upper Pragian and the lower Emsian. Three genera and 17 species are recognized: “Monograptus” (microdon cf. microdon, microdon curvatus); Neomonograptus (cf. atopus, aequabilis, bardoensis, falcarius, notoaequabilis); and Uncinatograptus (birchensis, craigensis, hercynicus, langgunensis, parangustidens, subhercynicus, telleri, thomasi, uniformis, yukonensis).

NOTES ON SOME ARCTIC COLLEMBOLA

1938 ◽  
Vol 70 (7) ◽  
pp. 151-154 ◽  
Author(s):  
H. G. James
Keyword(s):  
Canadian Arctic ◽  
Ellesmere Island ◽  
The Arctic ◽  
Baffin Island ◽  
Arctic Circle ◽  
Far North ◽  
Southern Shore

The following notes were made from a study of several species of Arctic Coollembola collected by Mr. W. J. Brown, of the Division of Entomology, Ottawa. Mr. Brown accompanied the voyage of the Canadian Arctic Patrol during August and September, 1935. During the trip he was able to collect on the southern shore of Baffin Island, and also well within the Arctic Circle as far north as Ellesmere Island.

Upper Homerian (upper Wenlock, Silurian) graptolites from arctic Canada

2002 ◽  
Vol 76 (2) ◽  
pp. 321-346 ◽  
Author(s):  
A. C. Lenz ◽  
A. Kozłowska-Dawidziuk
Keyword(s):  
New Species ◽  
Middle Part ◽  
Morphological Features ◽  
The Arctic ◽  
New Genera ◽  
Arctic Canada ◽  
Total Fauna ◽  
Biostratigraphic Units

An extraordinarily well-preserved upper Homerian (uppermost Wenlock) post-extinction (post-lundgreni Event) graptolite fauna is described from Arctic Canada. The fauna of dendroids, retiolitids and monograptids, predominantly of uncompressed and isolated material, demonstrates almost totally new morphological features in comparison with the pre-extinction fauna. The two species of the lowest post-extinction fauna are followed by a rapid proliferation in the middle part of the interval, resulting in the maximum diversity, 21 species, for the entire upper Homerian. The upper Homerian is divided into three biostratigraphic units: the lower nassadubius Biozone, middle praedeubeli-deubeli Biozone, and the upper ludensis Biozone. The total fauna consists of ten species of monograptids and 11 species of retiolitids; of the latter group, three (Baculograptus, Papiliograptus and Doliograptus) are new genera, and six (B. batesi, P. papilio,P.? petilus,D. latus,Doliograptus sp. A, and Spinograptus praerobustus) are new species. Among the recognized species of monograptids, only Colonograptus schedidoneus and Lobograptus? cornuatus are confined to the Arctic, while five species of retiolitids (B. batesi,P.? petilus,D. latus,Doliograptus sp. A, and Spinograptus praerobustus) appear to be endemic.

Systematics of the Acanthoparyphinae (Trilobita), by species from the Silurian of Arctic Canada

1998 ◽  
Vol 72 (4) ◽  
pp. 698-718 ◽  
Author(s):  
Jonathan M. Adrain
Keyword(s):  
New Species ◽  
Type Species ◽  
Cladistic Analysis ◽  
Canadian Arctic ◽  
Entire Group ◽  
Arctic Canada ◽  
Basal Node ◽  
The Family ◽  
Cape Phillips Formation ◽  
Basal Structure

Cladistic analysis of the trilobite subfamily Acanthoparyphinae Whittington and Evitt, 1954, yields an explicit hypothesis of relationship for the group. All Silurian species together form a robustly supported monophylum including the genera Hyrokybe Lane, 1972, Parayoungia Chatterton and Perry, 1984, and Youngia Lindström, 1885. Sister to this is the Ordovician type species of Acanthoparypha Whittington and Evitt, 1954. Remaining species that have historically been assigned to either Acanthoparypha or Pandaspinapyga Esker and Levin, 1964, form a rather labile paraphylum. Nevertheless, the entire group thus identified is definitely monophyletic, and supported by several prominent synapomorphic character-states.The basal structure and basal node of the subfamily are more difficult to assess. The relationships of the genera Hammannopyge Přibyl, Vaněk, and Pek, 1985, Holia Bradley, 1930, and Nieszkowskia Schmidt, 1881, need to be addressed within the wider context of the family as a whole. The traditional assignment of Holia to the acanthoparyphines is followed.Wenlock acanthoparyphines from the Cape Phillips Formation of the central Canadian Arctic islands include several species of Hyrokybe and Parayoungia. They are similar to, and in one case conspecific with, coeval forms to the southwest in the southern Mackenzie Mountains.Five species are new: Holia glabra, Hyrokybe lightfooti, Hyrokybe youngi, Hyrokybe mitchellae, and Parayoungia mclaughlini. At least four other potentially new species are reported in open nomenclature.

A new species of Droharhynchia (Brachiopoda) from the lower Middle Devonian (Eifelian) of west-central Alaska

1994 ◽  
Vol 68 (6) ◽  
pp. 1235-1240 ◽  
Author(s):  
Mary E. Baxter ◽  
Robert B. Blodgett
Keyword(s):  
New Species ◽  
Middle Devonian ◽  
The Arctic ◽  
Geographic Proximity ◽  
Brooks Range ◽  
West Central ◽  
Arctic Alaska ◽  
Northern Alaska ◽  
A New Species

A new species of the genus Droharhynchia Sartenaer is established from lower Eifelian strata of west-central Alaska and the northwestern Brooks Range of Alaska. Droharhynchia rzhonsnitskayae n. sp. occurs in the Cheeneetnuk Limestone of the McGrath A-5 quadrangle, west-central Alaska, and the Baird Group of the Howard Pass B-5 quadrangle, northwestern Alaska. These occurrences extend the lower biostratigraphic range of both the genus and the subfamily Hadrorhynchiinae into the Eifelian. They also suggest close geographic proximity of the Farewell terrane of southwestern and west-central Alaska and the Arctic Alaska superterrane of northern Alaska during Devonian time.

Metamorphic evolution of the Petersen Bay assemblage, Ellesmere Island: What can we learn about Pearya - Laurentia accretion?

2020 ◽  
Author(s):  
Karolina Kośmińska ◽  
Jane Gilotti ◽  
William McClelland ◽  
Matthew Coble
Keyword(s):  
Middle Devonian ◽  
Bulk Composition ◽  
Arctic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
Garnet Growth ◽  
Fold Belt ◽  
Weighted Mean ◽  
Northern Margin ◽  
Garnet Core

<p>The accretion of the Pearya terrane to the northern margin of Laurentia plays an important role in the paleogeographic reconstructions for the Arctic region. Earlier workers proposed a timing of its juxtaposition spanning from Late Silurian (Trettin, 1998) to Late Ordovician (Klaper 1992). In this study, we focus on the pressure-temperature-time (P-T-t) evolution of the Petersen Bay assemblage. This subduction related unit crops out between the crystalline basement of Pearya and volcano-sedimentary sequence of Clements Markham fold belt. The highest grade rocks, garnet-kyanite-bearing schist (sample 17-66) and garnet-kyanite-staurolite garbenschiefer (sample 17-64) were selected for P-T studies and in-situ monazite U-Pb dating by sensitive high resolution ion microprobe.</p><p>Thermodynamic modelling of sample 17-66 gives a P-T condition of 7.8-8.1 kbar and 590-610°C for garnet core formation, whereas a pseudosection calculated for the effective bulk composition indicates garnet rim growth at 8-9 kbar and 650-660°C. The QuiG Raman barometry coupled with Ti-in-biotite thermometry yield conditions of 6.5-7.5 kbar and 540-600°C for the garnet growth. The combination of QuiG barometry and Ti-in-biotite thermometry indicate garnet growth at 7.5-8 kbar and 500-550°C for the garbenschiefer sample.</p><p>Monazite shows distinctive zonation and 2, up to 3, domains were recognized based on textures and X-ray microprobe maps. For the sample 17-66, Monazite-I forms inclusions within garnet rims or cores of bigger matrix grains. It defines a weighted mean <sup>206</sup>Pb/<sup>238</sup>U age of 397±2 Ma (n=18, MSWD=1.6). Monazite-II occurs in the matrix and gives an age of 385±2 Ma (n=19, MSWD=1.5). Monazite-I from sample 17-64 yields a weighted mean <sup>206</sup>Pb/<sup>238</sup>U age of 394±2 Ma (n=11, MSWD=0.6). Monazite-II defines the age of 388±2 Ma (n=7, MSWD=0.8). Monazite-III was distinct only in garbenschiefer. It yields a younger age of 374±6 Ma (n=6, MSWD=3.1).</p><p>The P–T data coupled with monazite dating suggest a Middle Devonian metamorphism of the Petersen Bay assemblage under amphibolite facies conditions. These new results suggest that the juxtaposition of the Pearya terrane, Petersen Bay assemblage and the Clemens Markham fold belt is Middle Devonian or younger, i.e. much younger than previously thought.</p><p>References</p><p>Klaper E.M. 1992. The Paleozoic tectonic evolution of the northern edge of North America: A structural study of Northern Ellesmere Island, Canadian Arctic Archipelago Tectonics, 11, 854–870.</p><p>Trettin H.P. 1998. Pre-Carboniferous geology of the northern part of the Arctic Islands: Northern Heiberg Fold Belt, Clements Markham Fold Belt, and Pearya; northern Axel Heiberg and Ellesmere islands GSC Bulletin, 425, 401 p.</p>

New species of the cyathaspididPoraspis(Agnatha: Heterostraci) from the Late Silurian and Early Devonian of Northwest Territories, Canada

1998 ◽  
Vol 72 (2) ◽  
pp. 360-370 ◽  
Author(s):  
David K. Elliott ◽  
Elizabeth J. Loeffler ◽  
Yuhai Liu
Keyword(s):  
New Species ◽  
Eastern Europe ◽  
Northwest Territories ◽  
Canadian Arctic ◽  
Geographic Range ◽  
Center Of Origin ◽  
Early Devonian

Four new species of cyathaspidid extend the range of the genusPoraspisback into the Late Silurian and indicate that the Canadian arctic was its center of origin.Poraspis heintzaen. sp., P. cracens n. sp.,P. thulesn. sp. andP. parmulan. sp. also increase the known geographic range of the genus which had previously been reported only from the District of Mackenzie (NWT, Canada), Spitsbergen, western and eastern Europe. The identification ofP. sericeafrom the upper member of the Peel Sound Formation substantiates correlation of this interval with thecrouchizone of the Anglo-Welsh Borders, and provides another rare example of a species common to the Canadian arctic and European successions.

Validity and composition of the Silurian trilobite genera Borealarges and Dicranogmus, with new species from the Canadian Arctic

2003 ◽  
Vol 40 (5) ◽  
pp. 749-763 ◽  
Author(s):  
Jonathan M Adrain
Keyword(s):  
New Species ◽  
Cladistic Analysis ◽  
Species Group ◽  
Reasonable Doubt ◽  
The Arctic ◽  
Arctic Canada ◽  
New Information ◽  
Cape Phillips Formation ◽  
New Material ◽  
Three New Species

New silicified material from Arctic Canada demonstrates that the lichid trilobite genera Borealarges and Dicranogmus, recently claimed to be synonyms, are independent groups with no close phylogenetic connection to one another. Dicranogmus has been known mainly from cranidia alone; prior association of librigenae and pygidia with the Arctic Canadian species D. skinneri has been queried. This association is correct beyond reasonable doubt, based on description of new material of both D. skinneri and a new species. Three new species of Borealarges are related to B. tuckerae Adrain 1994. Cladistic analysis supports the monophyly of this species group. Pending further new information, however, the group is retained within the genus Borealarges. The stratigraphic range of the species group is extended from the lower Wenlock (Sheinwoodian) to upper Ludlow (Ludfordian) by the discovery of a rare species in the Douro Formation of Cornwallis Island, Arctic Canada. New taxa from the Wenlock of the Cape Phillips Formation, Arctic Canada, include Dicranogmus wynni, Borealarges nicoae, B. warholi, and B. yulei.

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