Devonian

1992 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
B. J. Bluck ◽  
J. C. W. Cope ◽  
C. T. Scrutton
Keyword(s):  
Lower Devonian ◽  
Quaternary System ◽  
Upper Devonian ◽  
Type Locality ◽  
System Boundary ◽  
Red Sandstone ◽  
Stratotype Section ◽  
Lacustrine Facies ◽  
Selection Of ◽  
Upper Boundary

AbstractThe Devonian System was the first pre-Quaternary system to have its base established at an internationally ratified Global Stratotype Section and Point (GSSP). The base of the System was defined at the base of the Monograptus uniformis Biozone at Klonk in Czechoslovakia (McLaren 1977). The upper boundary of the System is fixed by the base of the Carboniferous, which has been recently ratified in a GSSP at La Serre, Herault, France, at a point coincident with the first appearance of the conodont Siphonodella sulcata.Series. GSSPs have now been designated to define the bases of the Middle and Upper Devonian Series (that of the Lower Devonian being automatically defined by the System boundary).Stages. Consequent upon the selection of a Czech type section for the basal boundary stratotype of the System, the Germanic stages for the lowest parts of the Devonian were no longer appropriate and Lochkovian and Pragian stages have now been formally defined with stratotypes ratified by the I.U.G.S.Devon, the nomenclatorial type locality for the Devonian System (Sedgwick & Murchison 1839) is a region of great tectonic complexity and has not provided suitable sections on which to base international correlations. However, the rocks are frequently richly fossilferous and firm correlations can now be established with the intensively studied developments of the Devonian in Belgium and Germany.Northwards from Devon are found large tracts of the predominantly fluviatile and lacustrine facies which characterizes the Old Red Sandstone. Correlation between the marine Devonian rocks of southwest England and the

The Silurian-Devonian fossil record of the Myriapoda

1985 ◽  
Vol 309 (1138) ◽  
pp. 227-237 ◽  
Keyword(s):  
New York ◽  
Fossil Record ◽  
Discrete Group ◽  
Lower Devonian ◽  
New York State ◽  
Upper Devonian ◽  
York State ◽  
Red Sandstone ◽  
Terrestrial Invertebrates ◽  
Terrestrial Invertebrate

The oldest recorded terrestrial invertebrates are various small Diplopods (millepedes) from the Lower Old Red Sandstone of Britain which were probably preserved preferentially due to their robust calcified exoskeleton. While the myriapod affinities and terrestrial habits of the earliest, pre-Prídolí, claims are highly questionable, true diplopods are known from the latest Silurian (Stonehaven Group) and Lower Devonian of Scotland. In addition, a variety of enigmatic myriapod-like arthropods occur sporadically in the late Silurian-Lower Devonian freshwater facies of the M idland Valley of Scotland and Welsh Borderlands. Among these, the kampecarids ss. constitute a discrete group of short-bodied, diplopodous uniramian arthropods, possibly with myriapod affinities and aquatic habits. In contrast to the diversity of chelicerate groups represented in the later terrestrial invertebrate faunas of Rhynie, Aiken and Gilboa, the Middle to Upper Devonian fossil record of the Myriapoda is very sparse. While true diplopods are notably absent, a variety of fragmentary chilopods (centipedes) are now known from the Gilboa Fauna (Givetian) of New York State.

St Audrie's Bay, Somerset, England: a candidate Global Stratotype Section and Point for the base of the Jurassic System

1994 ◽  
Vol 131 (2) ◽  
pp. 191-200 ◽  
Author(s):  
G. Warrington ◽  
J. C. W. Cope ◽  
H. C. Ivimey-Cook
Keyword(s):  
Type Locality ◽  
International Commission ◽  
The West ◽  
West Side ◽  
Type Area ◽  
Jurassic System ◽  
Stratotype Section

AbstractIn 1967 the Somerset coastline near Watchet was proposed as the type area of the basal (Planorbis) chronozone of the Hettangian Stage and thus of the Jurassic System. Neither at that time nor subsequently, however, has a type locality and section been nominated from those available in the area. There is urgent need to select a Global Stratotype Section and Point (GSSP) for the base of the Hettangian, and of the Jurassic System. The cliff forming the headland at the west side of St Audrie's Bay, three kilometres east of Watchet, Somerset, is here proposed as the type locality and section, with the base of the Hettangian Stage, at the base of the Planorbis Chronozone, being placed at the horizon currently recognized as that at which ammonites of the genus Psiloceras appear. In this section the base of the Planorbis Chronozone corresponds with the base of the Psiloceras planorbis Biozone. The proposal of this section is conditioned by the availability of comprehensive litho- and biostratigraphic information, and the ability of the section to fulfil International Commission on Stratigraphy (ICS) requirements for a candidate GSSP.

XV.—On Rhamphodopsis, a Ptyctodont from the Middle Old Red Sandstone of Scotland

1938 ◽  
Vol 59 (2) ◽  
pp. 397-410 ◽  
Author(s):  
D. M. S. Watson
Keyword(s):  
Upper Devonian ◽  
Red Sandstone ◽  
Number Of Teeth ◽  
Devonian Age

In 1858 C. H. Pander described as Ptydodus a number of teeth from Upper Devonian limestones in Russia. His admirable figures of complete teeth and of sections through them established the very chimæroid structure of these bodies. Since that time similar teeth have been repeatedly described, and have served for the establishment of three genera and many species from rocks of Middle and Upper Devonian age.

The Devonian actinopterygianCheirolepisAgassiz

1979 ◽  
Vol 70 (13-14) ◽  
pp. 337-399 ◽  
Author(s):  
D. Michael Pearson ◽  
T. Stanley Westoll
Keyword(s):  
Body Shape ◽  
Upper Devonian ◽  
Specific Level ◽  
Red Sandstone ◽  
Incertae Sedis ◽  
Mode Of Life ◽  
Interesting Variation ◽  
Small Bones ◽  
Rostral Region ◽  
Head Skeleton

SynopsisThe structure of the fishes constituting the Devonian genusCheirolepisis investigated. Articulated remains from the Scottish Old Red Sandstone and the Canadian Upper Devonian were studied and two species are recognised, the Middle DevonianC. trailliand the Upper DevonianC. canadensis.Recently described fragmentary material from Europe assigned to the genus is best regarded asincertae sedis. Cheirolepisis the earliest actinopterygian genus with extensive material. Neurocranial remains are described, with a crossopterygian-like parasphenoid. There seems to have been a mobile rostral region with several small bones between premaxilla and postrostral extending to the anterior corner of the small dermal orbit. New palatoquadrate and pectoral girdle material is described. The apparently primitive nature of the head skeleton is related to the cranial dynamics and the likely mode of life. The small scales and the elongate-fusiform body shape are a corollary of the method of swimming. The ecology of the fishes is touched upon. A taxonomic investigation of the two species was carried out but although interesting variation in the scale-row numbers came to light no changes at the specific level were deemed necessary. Revised generic and specific diagnoses are given.

Observations sur la sedimentation argileuse du debut des temps tertiaires en Aquitaine

1963 ◽  
Vol S7-V (3) ◽  
pp. 303-306 ◽  
Author(s):  
Andre Klingebiel
Keyword(s):  
Tropical Climate ◽  
Climatic Conditions ◽  
Red Sandstone ◽  
Marine Deposits ◽  
The Core ◽  
Analogous Composition ◽  
Aquitaine Basin ◽  
Lacustrine Facies

Abstract Examination of a section which cuts into the Dreuilhe anticline in the southern Aquitaine basin (Plantaurel) reveals a similarity between the deposits there and those in the northern part of the basin. In the core of the anticline the Maestrichtian lower red marls contain clays and red sandstone with montmorillonite and kaolinite, suggesting deposition in a vast depression lacking sufficient drainage, and in a medium rich in Ca (super ++) and Mg (super ++) . The upper red marls in the hard band of Montian lacustrine limestone with Microcodium have an analogous composition and correspond to calm tectonic and climatic conditions. Lacustrine marls with attapulgite directly underlie the transgressive Thanetian marine deposits. The passage from the Thanetian to the Sparnacian is marked by lacustrine facies, predominantly montmorillonite, and an increasing abundance of illites. The dominance of montmorillonite in a tectonically unstable area suggests that the adjacent continental mass was of low relief and was characterized by a tropical climate with alternating dry and humid seasons. The increase in kaolinite accompanying the arrival of the coarse detritus of the Ypresian is interpreted as the result of rhexistasy. The Lutetian is characterized by sandstones and limestones with associated montmorillonite, illite, and kaolinite. This phase represents the return of the sea, and the detrital nature of the deposits is a result of the uplift of the Pyrenean massifs. These phenomena are analogous to those that have been reported previously from the Paleocene series of Bordelais (northern part of the basin) suggesting a similar paleogeographic evolution for the two areas.

A new chasmataspid (Chelicerata: Chasmataspida) from the Lower Devonian of the Midland Valley of Scotland

1998 ◽  
Vol 89 (3) ◽  
pp. 161-165 ◽  
Author(s):  
Jason A. Dunlop ◽  
Lyall I. Anderson ◽  
Simon J. Braddy
Keyword(s):  
Lower Devonian ◽  
Type Locality

AbstractA new chasmataspid (Chelicerata, Chasmataspida) is described as Forfarella mitchelli gen. et sp. nov. from the Lower Devonian of Scotland. This species is problematic in that it was catalogued under the name Forfarella mitchelli Waterston (no date), but was never formally described. Furthermore, its type locality is uncertain. Chasmataspids are a poorly known taxon within Chelicerata which appear to be closely related to eurypterids. F. mitchelli is only the fourth chasmataspid species to be described. Though poorly preserved, it shows affinities with other Devonian chasmataspids and supports the hypothesis that this group may have been more geographically widespread in the Devonian than has previously been recognised.

Correlation of calcareous nannofossil zones to the local first occurrence of Pachydiscus neubergicus (von Hauer, 1858) (Ammonoidea) in European Upper Cretaceous sections

2003 ◽  
Vol 82 (3) ◽  
pp. 283-288 ◽  
Author(s):  
M. Wagreich ◽  
T. Küchler ◽  
H. Summesberger
Keyword(s):  
Upper Cretaceous ◽  
Type Locality ◽  
Calcareous Nannofossil ◽  
Northern Spain ◽  
Northern Margin ◽  
First Occurrence ◽  
Stratotype Section ◽  
Sw France

AbstractThe first occurrence (FO) of the ammonite Pachydiscus neubergicus (von Hauer, 1858) has been correlated to calcareous nannofossil zonations in several European sections along the northern margin of the Tethyan palaeobiogeographic realm. Both the proposed stratotype section of Tercis (SW France) and complete, ammonite-bearing sections in northern Spain document the FO of P. neubergicus within standard nannofossil zone CC23a (UC16), below the LO of Broinsonia parca constricta. Other sections such as the type locality Neuberg (Austria), Nagoriani (the Ukraine) and Bjala (Bulgaria) indicate considerable diachroneity of local FOs and show P. neubergicus to range up to nannofossil zone CC25b/c (UC20; Late Maastrichtian).

Lower Devonian plant and spore assemblages from Lower Old Red Sandstone strata of Tredomen Quarry, South Wales

2011 ◽  
Vol 165 (3-4) ◽  
pp. 183-208 ◽  
Author(s):  
Jennifer L. Morris ◽  
John B. Richardson ◽  
Dianne Edwards
Keyword(s):  
Lower Devonian ◽  
Red Sandstone ◽  
South Wales

Arthropod ichnofauna of the Old Red Sandstone at Dunure and Montrose, Scotland

1985 ◽  
Vol 76 (2-3) ◽  
pp. 287-297 ◽  
Author(s):  
Elaine F. Walker
Keyword(s):  
Lower Devonian ◽  
Trace Fossils ◽  
Red Sandstone

ABSTRACTSediments which occur frequently within Lower Devonian andesites of the Midland Valley of Scotland have so far yielded trace fossils in only two areas: Dunure, Ayrshire and Montrose, Angus.Smith (1909) interpreted the trace fossils from Dunure as representing an “Upland Fauna” and he named 23 new ichnogenera. Re-examination of his localities and specimens suggests that the environment was a shallow ephemeral lake and when sedimentological and preservational factors, size, behavioural variation and synonymy are taken into account, only 8 ichnogenera are here considered valid. These are redefined as Siskemia, Stiaria, Danstairia, Keircalia, Stiallia, Isopodichnus (=Archatomia Smith), Mermia and Merostomichnites. The Montrose ichnofauna of 5 ichnogenera includes a large arthropod trackway Mitchellichnus ferrydenensis gen. and sp. nov.The trackways from both localities appear to have been formed by various merostomes, crustaceans and possibly early myriapods. The habitat was essentially aquatic although some arthropods may have been amphibious.

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