Microvertebrate assemblages from the Upper Silurian of Cornwallis Island, Arctic Canada

1999 ◽  
Vol 36 (3) ◽  
pp. 349-361 ◽  
Author(s):  
Carole J Burrow ◽  
Jo MJ Vergoossen ◽  
Susan Turner ◽  
Tom T Uyeno ◽  
Ray Thorsteinsson
Keyword(s):  
New Species ◽  
Arctic Canada ◽  
Growth Zones ◽  
Upper Silurian ◽  
The Baltic ◽  
Cornwallis Island

Microvertebrate assemblages from four Upper Silurian (?Ludlow-Pridoli) localities on Cornwallis Island, Arctic Canada, comprise mainly scales, plus dentition cones and jaw fragments from ischnacanthid acanthodians, with rare scales assigned to heterostracan Lepidaspis? sp., ?chondrichthyan Arauzia? sp., and Placodermi? gen. et sp. indet. Most of the scales in sample C-11460 are assigned to the poracanthodid acanthodian Poracanthodes canadensis sp.nov., which shows closest affinity to Poracanthodes punctatus Brotzen variants from the Baltic Pridoli. The flank scales of the new species resemble those of P. punctatus s.s. (Silurian variant; the zone fossil for the late Pridoli in the Standard Silurian microvertebrate scheme), with their superposed crown growth zones, rows of small pores aligned with the underlying zones, number of radial canals, and "arcade" canals connecting these radial canals. They differ in having numerous anterior crown riblets, "zig-zag" rather than straight crown pore rows, and V-shaped arcade canals.

Atrypoidea zonation of the Upper Silurian Read Bay Formation of Somerset and Cornwallis Islands, Arctic Canada

1979 ◽  
Vol 16 (12) ◽  
pp. 2204-2218 ◽  
Author(s):  
Brian Jones
Keyword(s):  
Carbonate Rocks ◽  
Basal Part ◽  
Arctic Canada ◽  
Pressure Point ◽  
Species Overlap ◽  
Conodont Zone ◽  
Upper Silurian ◽  
Somerset Island ◽  
Cornwallis Island ◽  
Distinct Distribution

Species of the brachiopod genus Atrypoidea have a distinct distribution in carbonate rocks of the late Silurian Read Bay Formation of Arctic Canada. Atrypoidea phoca occurs in the basal part of the formation and this species is succeeded by Atrypoidea foxi forma B at higher levels. The ranges of the two species overlap, defining a third useful zone. Locally, as in the Pressure Point area of northwestern Somerset Island, Atrypoidea foxi forma B is succeeded by Atrypoidea foxi forma A. Atrypoidea foxi forma A is generally restricted to carbonates with a low content of detrital material and has a significantly larger shell than Atrypoidea foxi forma B. A higher zone is defined by Atrypoidea erebus which occurs in the basal part of the Somerset Island Formation on Somerset Island and in the basal part of member C of the Read Bay Formation at Goodsir Creek on Cornwallis Island. At the latter locality, Atrypoidea foxi forma A is found with Atrypoidea erebus, thereby demonstrating their overlapping ranges.The overlapping ranges of Atrypoidea phoca and Atrypoidea foxi forma B occur in the middle to late Ludlovian ploeckensis–siluricus conodont zones. On Somerset Island, Atrypoidea foxi forma B and Atrypoidea foxi forma A range through the ploeckensis–siluricus conodont zone. Atrypoidea erebus occurs in late Ludlovian and (or) early Pridolian strata.

Silurian trilobites from arctic Canada

1979 ◽  
Vol 116 (1) ◽  
pp. 1-19 ◽  
Author(s):  
A. T. Thomas ◽  
G. M. Narbonne
Keyword(s):  
New Species ◽  
Arctic Canada ◽  
Subtidal Environment ◽  
Storm Wave ◽  
Shallow Subtidal ◽  
Cornwallis Island

SummaryTrilobites of upper Ludlow age are described from Member A of the Read Bay Formation on Cornwallis Island. Four new species are represented: Helokybe spio gen. et sp.nov. (Dechenellinae), Encrinurus hyperboreus sp. nov., Kailia? capra sp.nov. (Encrinurinae) and Hemiarges echinatus sp.nov. Other taxa present are: an effaced scutelluid; Cyphaspis sp.; a warburgelline; two more encrinurids; two other forms of Hemiarges. The trilobites occur in sediments indicative of a shallow subtidal environment, with the exception of the warburgelline which occurs in sediments deposited under deeper subtidal conditions below storm wave-base.

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.

Upper Silurian trilete spores and other microfossils from the Read Bay Formation, Cornwallis Island, Canadian Arctic

1978 ◽  
Vol 15 (8) ◽  
pp. 1292-1303 ◽  
Author(s):  
D. C. McGregor ◽  
G. M. Narbonne
Keyword(s):  
New Species ◽  
Marine Environment ◽  
Vascular Plants ◽  
Canadian Arctic ◽  
Type Section ◽  
Stratigraphic Framework ◽  
Near Shore ◽  
Upper Silurian ◽  
One New Species ◽  
Cornwallis Island

A diverse palynomorph assemblage of trilete spores, tetrads, acritarchs, chitinozoans, scolecodonts, and fragments of arthropods, ?hydrozoans, ?graptolites, and possibly nematophytalean and vascular plants occurs 20 m above the base of member B of the Read Bay Formation at the type section on eastern Cornwallis Island, District of Franklin. This assemblage, here described briefly, is late Ludlow according to faunas above and below. The palynomorphs, other fossils, and stratigraphic framework indicate that the shales of member B were deposited in a sheltered near-shore marine environment. One new species of trilete spores, Retusotriletes chartulatus McGregor, is erected.

Insolitignum n.gen. and Palaeoephippium Goodbody 1986 (Radiolaria) from the Lower Silurian of the Cape Phillips Formation, Arctic Canada

1999 ◽  
Vol 36 (12) ◽  
pp. 2051-2057 ◽  
Author(s):  
Eugene W MacDonald
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Intermediate Position ◽  
Arctic Canada ◽  
Lower Silurian ◽  
The Family ◽  
Cape Phillips Formation ◽  
Cornwallis Island

Radiolaria of the family Palaeoscenidiidae were recovered from two bedded-limestone and two limestone-concretion samples from the upper Llandovery of the Cape Phillips Formation, Cornwallis Island, Arctic Canada. The new genus Insolitignum is defined by two apical rays, three basal rays, and a principal ray in an intermediate position. The principal ray distinguishes this genus from Palaeoephippium. Insolitignum dissimile, the type species of the new genus, was previously placed in Palaeoephippium. New species described here are Insolitignum peranima, Insolitignum vivanima, and Palaeoephippium adraini.

Llandovery secuicollactinae and rotasphaeridae (radiolaria) from the Cape Phillips Formation, Cornwallis Island, Arctic Canada

1998 ◽  
Vol 72 (4) ◽  
pp. 585-604 ◽  
Author(s):  
Eugene W. MacDonald
Keyword(s):  
New Species ◽  
New Genus ◽  
Arctic Canada ◽  
Cape Phillips Formation ◽  
Cornwallis Island ◽  
Lattice Shells

Radiolaria extracted from two bedded-limestone and two limestone-concretion samples from the upper Llandovery of the Cape Phillips Formation, Cornwallis Island, allow the distinction between the spicular haplentactinid subfamily Secuicollactinae and the nonspicular Rotasphaeridae. This restores Secuicollactinae and returns Secuicollacta to the subfamily from the Rotasphaeridae. Secuicollactinae represent 36 percent of the fauna and are assigned to three genera, Secuicollacta, Diparvapila new genus, and Parvalanapila new genus; these form 27, five, and three percent of the fauna, respectively. The remaining one percent of the subfamily is unassigned. Rotasphaeridae form four percent of the fauna and are represented by Rotasphaera. Secuicollacta is diagnosed on the basis of the presence of an ectopic spicule in addition to several rotasphaeridlike primary units. The salient characters of Diparvapila include two lattice shells with an ectopic spicule on the medullary shell. Parvalanapila is diagnosed on the basis of a lattice sphere overlain by a labyrinthine layer and an ectopic spicule on the lattice sphere. New species described here are Secuicollacta malevola, S. sceptri, S. gliris, S. herrimani, S. segari, S. vallipuellae, S. resodiosae, S. glaebosa, S. teli, Diparvapila hicocki, D. saintrochae, D. larseni, Parvalanapila fleischerorum, and Rotasphaera severa. Four species of Secuicollacta are reported in open nomenclature, as are two of Diparvapila and two of Rotasphaera.

Palaeocope ostracods from the Silurian Wenlock Series of Arctic Canada

2010 ◽  
Vol 47 (6) ◽  
pp. 913-925
Author(s):  
C. Giles Miller ◽  
Mark Williams ◽  
David J. Siveter
Keyword(s):  
Lake Area ◽  
Arctic Canada ◽  
Level Change ◽  
Carbon Isotope Excursion ◽  
Low Diversity ◽  
Cape Phillips Formation ◽  
Global Sea Level ◽  
The Baltic ◽  
Cornwallis Island ◽  
Ostracod Species

Silurian Wenlock Series deposits of the Cape Phillips Formation on Baillie-Hamilton Island and Cornwallis Island, Arctic Canada, have yielded a silicified ostracod assemblage that spans the late Sheinwoodian and Homerian stages. Sixteen palaeocope ostracod species are recorded, including the new species Beyrichia ( Beyrichia ) marssae , Gabrielsella ? copelandi , and Platybolbina ( Abruptobolbina ) adraini . The ostracod faunas can be linked into local trilobite, microvertebrate, and graptolite zonal schemes, and a few of the ostracod species offer potential for local and perhaps wider biostratigraphical correlation. The ostracods are mostly known only from the Cape Phillips Formation, but also include two taxa found in the Wenlock Series of the Avalanche Lake area, Northwest Territories, Canada. Other ostracod species suggest links with Silurian successions in northern Canada and the Baltic. Low-diversity ostracod faunas characterize the level of a marked positive carbon isotope excursion and coeval mid-Homerian regression at the level of the regional Pristiograptus dubius – Gothograptus nassa graptolite Biozone. Comparison with the pattern of distribution of coeval ostracod faunas elsewhere in Canada suggests that diversity changes in the Cape Phillips Formation ostracod faunas are controlled by local palaeoenvironmental factors perhaps linked to global sea-level change.

Review of Mycetobia Meigen, 1818 (Diptera, Anisopodidae) in the Eocene ambers

Zootaxa ◽  
2019 ◽  
Vol 4544 (1) ◽  
pp. 1 ◽  
Author(s):  
MACIEJ WOJTOŃ ◽  
IWONA KANIA ◽  
WIESŁAW KRZEMIŃSKI
Keyword(s):  
New Species ◽  
Baltic Amber ◽  
The Baltic

A revision of the genus Mycetobia Meigen, 1818 from the Eocene is presented. Redescription of Mycetobia connexa Meunier, 1899 known from the Baltic amber is given and documented by photographs and drawings. Five new species of Mycetobia from Eocene resins are described, four from Baltic amber: Mycetobia christelae sp. nov., Mycetobia hansi sp. nov., Mycetobia silvia sp. nov., Mycetobia szwedoi sp. nov. and one from the Ukrainian amber: Mycetobia perkovskyi sp. nov. Key to the species of Mycetobia known from the Eocene is provided. 

A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography

Zootaxa ◽  
2011 ◽  
Vol 2742 (1) ◽  
pp. 60 ◽  
Author(s):  
DAVID PENNEY ◽  
ANDREW MCNEIL ◽  
DAVID I. GREEN ◽  
ROBERT BRADLEY ◽  
YURI M. MARUSIK ◽  
...  
Keyword(s):  
New Species ◽  
Phase Contrast ◽  
Baltic Amber ◽  
X Ray ◽  
The Family ◽  
X Ray Computed ◽  
Micro Tomography ◽  
The Baltic ◽  
A New Species ◽  
Eocene Amber

A new species of the extant spider family Anapidae is described from a fossil mature male in Eocene amber from the Baltic region and tentatively assigned to the genus Balticoroma Wunderlich, 2004. Phase contrast X-ray computed micro-tomography was used to reveal important features that were impossible to view using traditional microscopy. Balticoroma wheateri new species is easily diagnosed from all other anapids by having clypeal extensions that run parallel to the ectal surface of the chelicerae and in having the metatarsus of the first leg highly reduced and modified into what is presumably a y-shaped clasping structure. Although only a single extant anapid species occurs in northern Europe, the family was diverse in the Eocene. The discovery of yet another anapid species in Baltic amber supports the idea that Eocene European forests may have been a hotspot of evolution for this family of spiders.

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