Upper Devonian miospores from the Escuminac Formation, eastern Québec, Canada

1970 ◽  
Vol 7 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Wayne W. Brideaux ◽  
Norman W. Radforth
Keyword(s):  
Middle Devonian ◽  
Russian Platform ◽  
Upper Devonian ◽  
New Combinations ◽  
Lower Carboniferous ◽  
The Third ◽  
Large Size ◽  
Assem Blages ◽  
Small Spore ◽  
Orcadian Basin

Miospores of early Frasnian age are described from the third unit of the Escuminac Formation in eastern Québec, Canada. The assemblage comprises 34 species, including 8 species proposed as new, 2 new combinations, and 12 sparsely represented forms not considered synonymous with previously described species.The assemblage is most closely comparable to a Middle Devonian assemblage from the Orcadian Basin, Scotland. Similarities are also noted with European and Russian assemblages, particularly from the Eifelian–Givetian of the Russian Platform. Except for five long-ranging species, elements of Lower Carboniferous assemblages are lacking. Evidence suggests a transitional nature for this Escuminac assemblage. Miospores of relatively large size, a feature of Middle Devonian assemblages, are present. Marked differentiation of large and small spore types, found in several other Upper Devonian assem blages is absent. Apiculate and anchor-spined species dominate the Escuminac assemblage.

Deformation history in part of the Lubec–Belleisle zone of southern New Brunswick

1970 ◽  
Vol 7 (3) ◽  
pp. 748-767 ◽  
Author(s):  
R. L. Brown ◽  
H. Helmstaedt
Keyword(s):  
New Brunswick ◽  
Middle Devonian ◽  
Maximum Principal Stress ◽  
Upper Devonian ◽  
Second Phase ◽  
Lower Carboniferous ◽  
The North ◽  
Principal Compressive Stress ◽  
Two Phases ◽  
Paleozoic Rocks

Rocks of the Proterozoic Coldbrook Group on the north shore of the Bay of Fundy, New Brunswick, are bounded to the north by a major northeast trending fault (Lubec–Belleisle). North of the fault Paleozoic rocks of the Mascarene Group are overlain unconformably by Upper Devonian and Lower Carboniferous strata.Both the Coldbrook and Mascarene Groups have been deformed by three phases of deformation. Deformation of the two Groups was coeval; penetrative fabrics first developed during the Acadian (Middle Devonian) orogeny.Pre-Acadian Paleozoic movements were limited to local or regional uplift with possible attendant warping and/or gentle tilting.Mylonitic fabrics formed in Coldbrook rocks during the first two phases of the Acadian polyphase deformation. These northeast trending s- surfaces lie normal to the direction of maximum finite shortening. Also from the orientation of synmylonization quartz deformation lamellae of the second phase, it is apparent that the local trajectory of the maximum principal stress was normal to the s-surfaces of the mylonites.No evidence for major northeast–southwest strike slip faulting has been found. Fracture analyses in Upper Devonian and Lower Carboniferous rocks in the northeast trending fault zone, point to a northwest trending principal compressive stress.It is contended that the bulk of the ductile strain (first two phases) occurred In response to northwest principal compressive stress during the Middle Devonian, and these stresses were re-established in post-Devonian times, resulting in the development of high angle oblique to dip slip movements on the northeast trending faults.

The major pre-Mississippian unconformity in Rock Canyon, central Wasatch Range, Utah

2014 ◽  
Vol 1 ◽  
pp. 1-5
Author(s):  
David Clark ◽  
Drew Derenthal ◽  
Bart Kowallis ◽  
Scott Ritter
Keyword(s):  
Upper Devonian ◽  
Large Size ◽  
Preliminary Work ◽  
Mississippian Rocks

In central Utah, the major pre-Mississippian unconformity is fairly well understood at most of the localities where it is recognized. However, the unconformity is more enigmatic in Rock Canyon of the central Wasatch Range. At this locality, dolomitization of most pre-Mississippian rocks obscures stratigraphic identification of Devonian and older units. The absence of any identifiable angular relationship further complicates resolution. Because of this, both identification of the stratigraphic level of the unconformity and, consequently, its magnitude remain controversial. Large-size dolomite samples taken in Rock Canyon at closely spaced intervals for the 3.6-m directly below definite Upper Devonian rocks yield microfossils, including conodonts, in the uppermost 1.6-m of that interval that indicate no unconformity exists between the Cambrian Maxfield Limestone and the Upper Devonian-Lower Mississippian Fitchville Dolomite at the horizon previously identified as unconformable. Rather, an unknown thickness of dolomitized Upper Devonian Pinyon Peak Formation and probable older rock (possibly Bluebell Dolomite and Victoria Formation) occurs between the top of definite Maxfield and base of the Fitchville. The identification of the unconformity horizon remains unknown. Our preliminary work outlines a promising procedure for future understanding of the magnitude and stratigraphic level of the unconformity.

scholarly journals Jaws of a large belemnite and an ammonite from the Aalenian (Middle Jurassic) of Switzerland

2020 ◽  
Vol 139 (1) ◽  
Author(s):  
Christian Klug ◽  
Walter Etter ◽  
René Hoffmann ◽  
Dirk Fuchs ◽  
Kenneth De Baets
Keyword(s):  
Middle Jurassic ◽  
Opalinus Clay ◽  
Northern Switzerland ◽  
The Third ◽  
Large Size ◽  
Upper Jaw ◽  
Rule Out

AbstractAlthough belemnite rostra can be quite abundant in Jurassic and Cretaceous strata, the record of belemnite jaws was limited to a few specimens from Germany and Russia. Here, we describe and figure three cephalopod jaws from the Middle Jurassic Opalinus Clay of northern Switzerland. Although flattened, the carbonaceous fossils display enough morphological information to rule out an ammonoid, nautiloid or octobrachian origin of the two larger jaws. Their similarities to belemnite jaws from Germany and Russia conforms with our interpretation of these specimens as belemnite jaws. Based on their rather large size, we tentatively assign these two jaws to the megateuthidid Acrocoelites conoideus. The third jaw is a rather small upper jaw of an ammonoid. Since Leioceras opalinum is by far the most common ammonite in this unit in northern Switzerland, we tentatively suggest that the upper jaw belongs to this species.

Two newly identified cheiracanthid acanthodians from the Mey Flagstone Formation (Givetian, Middle Devonian) of the Orcadian Basin, Scotland

2020 ◽  
Vol 57 (1) ◽  
pp. sjg2020-009
Author(s):  
Michael J. Newman ◽  
Jan L. den Blaauwen ◽  
Carole J. Burrow
Keyword(s):  
Middle Devonian ◽  
Leading Edge ◽  
Baltic Region ◽  
Head Region ◽  
Longitudinal Ridge ◽  
Orcadian Basin ◽  
First Time ◽  
Fin Spines

Articulated cheiracanthid acanthodians are relatively rare above the Dickosteus thrieplandi biostratigraphic zone in the Orcadian Basin, with Cheiracanthus peachi den Blaauwen, Newman & Burrow the only species identified to date. Here we describe two other taxa Fallodentus davidsoni nov. gen. et sp. and Markacanthus costulatus Valiukevičius from the Mey Flagstone Formation. F. davidsoni occurs at the base of the formation, in the Osteolepis panderi biostratigraphic zone, and is readily identified by its robust fin spines which have a wide longitudinal ridge on each side below the groove separating the leading edge from the side of the spine. The taxon is most similar to Homalacanthus concinnus (Whiteaves) from the younger (Frasnian) Escuminac Formation in Quebec, Canada. The unique specimen of Markacanthus costulatus is from the top of the Mey Flagstone Formation. This taxon was previously only known from isolated scales from the upper Narva and Aruküla Regional Stages of the east Baltic region. The dorsoventral preservation of the head region in the F. davidsoni specimens reveals clearly the position of the ceratohyal cartilages in a cheiracanthid, as well as showing for the first time that there is a basihyal cartilage anterior to the ceratohyals.

scholarly journals Glyptogidiella omanica gen. et sp. nov., an inland groundwater bogidiellid from Oman with enlarged coxal plate V (Crustacea, Amphipoda)

Zootaxa ◽  
2010 ◽  
Vol 2657 (1) ◽  
pp. 55 ◽  
Author(s):  
RONALD VONK ◽  
DAMIÀ JAUME
Keyword(s):  
New Genus ◽  
Sultanate Of Oman ◽  
New Genus And Species ◽  
The Third ◽  
Ground Waters ◽  
Large Size ◽  
The Family ◽  
Primary Habitat ◽  
Combined Display

A new genus and species of Amphipoda is reported from inland ground waters of the Sultanate of Oman. Although Glyptogidiella omanica gen. et sp. nov. exhibits several features typical of the Bogidiellidae (i. e. combined display of distinct carpal lobe on first gnathopod, reduced pleopodal rami, and unsegmented exopodite of third uropod), its exceptionally large fifth coxal plate and short rami of third uropod do not fit in the restricted diagnosis of the family as recently presented elsewhere. In fact, the enlarged coxal plate V is a feature not reported in any other amphipod, whereas no other bogidiellid displays an expanded basis on pereopod VII. The habitus of Glyptogidiella is not typical for a dweller of a true interstitial niche, with its short antennae, large coxal plate and short and stubby rami on the third uropod. This suggests that the interstitial medium could not be the primary habitat for the species, and that the underground of wadis might contain interstices of large size and could also be in contact with karstic hollows.

scholarly journals III. Contributions to the anatomy of the central nervous system in vertebrated animals. Part I.—Ichthyopsida. Section I.—Pisces. Subsection III.—Dipnoi. On the brain of the Ceratodus forsteri

1888 ◽  
Vol 43 (258-265) ◽  
pp. 420-423
Keyword(s):  
Fourth Ventricle ◽  
Third Ventricle ◽  
Pia Mater ◽  
The Third ◽  
Lateral Ventricles ◽  
Large Size ◽  
General Arrangement ◽  
Tela Choroidea ◽  
The Central Nervous System ◽  
The Brain

The brain of Ceratodus has the following general arrangement:—The membrane which represents the pia mater is of great thickness and toughness; there are two regions where a tela choroidea is developed: one where it covers in the fourth ventricle, and the other where it penetrates through the third ventricle and separates the lateral ventricles from each other. The ventricles are all of large size, and the walls of the lateral ventricles are not completed by nervous tissue. The thalamence-phalon and the mesencephalon are narrow, and the medulla oblongata is wide.

The order Fenestrata (Bryozoa) of the Toroweap Formation (Permian), southern Nevada

1994 ◽  
Vol 68 (4) ◽  
pp. 746-762 ◽  
Author(s):  
Miriam E. Mccolloch ◽  
Ernest H. Gilmour ◽  
Edward M. Snyder
Keyword(s):  
New Species ◽  
Hard Rock ◽  
Three Dimensional ◽  
Russian Platform ◽  
Rock Matrix ◽  
The Third ◽  
Southern Nevada ◽  
Analytical Procedures ◽  
Three New Species ◽  
Local Range

Recently developed analytical procedures for meshwork fenestrate and pinnate bryozoans made it possible to recognize two Russian species in the Toroweap Formation of southern Nevada. This analysis separates zoarial and zooecial features and emphasizes the three-dimensional form and size of the zooecial chamber as well as accessory features. In this investigation, these analytical procedures are successful even when specimens are fragmented and embedded in a hard rock matrix.The bryozoans in the Toroweap Formation in this study were found to be more similar to Permian species of the Russian platform than to species described in earlier North American Permian studies. Five species of fenestrate bryozoans are present in the Toroweap Formation. Wjatkella permiana Morozova, 1970, and Polypora sargaensis Trizna, 1948, originally described in Russia, are recognized in the Toroweap. Three new species, Penniretepora oppositus n. sp., Septopora bilateralis n. sp., and Reteporidra anaphora n. sp., are present and, along with the Russian species, are described in this paper.The local range zones of the five species of fenestrates were identified in three measured sections. Penniretepora oppositus and Septopora bilateralis are present throughout the three sections; Reteporidra anaphora is present in the lower two-thirds of the three sections; Wjatkella permiana is present in the middle parts of the three sections; and Polypora sargaensis is present in the upper parts of the three sections. Concurrent range zones, based on ramose bryozoans, were previously identified in two of the three sections and, using the distribution of the fenestrates in these two sections, four of the five concurrent range zones were recognized in the third section.

Phylogeny, speciation, and zonation of Siphonodella (Conodonta, Upper Devonian and Lower Carboniferous)

1978 ◽  
Vol 7 (2) ◽  
pp. 102-120 ◽  
Author(s):  
Charles A. Sandberg ◽  
Willi Ziegler ◽  
Klaus Leuteritz ◽  
Susan M. Brill
Keyword(s):  
Upper Devonian ◽  
Lower Carboniferous
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