An Early Devonian lake and its associated biota in the Midland Valley of Scotland

1995 ◽  
Vol 86 (4) ◽  
pp. 233-246 ◽  
Author(s):  
N. H. Trewin ◽  
R. G. Davidson
Keyword(s):  
Volcanic Activity ◽  
Fish Fauna ◽  
Early Devonian ◽  
Red Sandstone ◽  
Drainage Patterns ◽  
Terrestrial Environments ◽  
Climatic Regime ◽  
Lake Floor ◽  
The 19Th Century ◽  
Green Clay

ABSTRACTThe Tillywhandland fish bed of the Lower Old Red Sandstone in the Strathmore area of the Scottish Midland Valley accumulated in a lake, here called Lake Forfar, which was created suddenly following a period of fluvial deposition. Lake creation may have been due to basin faulting or the disruption of drainage patterns by contemporaneous volcanic activity. The fish bed laminites accumulated in a hydrologically open lake under a seasonal climatic regime. When fully developed, laminites comprise repeated quadruplets of clastic silt/carbonate/organic/green clay–shale laminae averaging 0·5 mm in thickness. Following 2000 years of laminite deposition an increasingly silty succession with thin current-rippled sandstones provided the lake-fill.The fish fauna is dominated by Mesacanthus and Ischnacanthus with rare Euthacanthus, Parexus, Climatius, Vernicomacanthus and Cephalaspis. Most fish carcasses were partially decayed before deposition in the laminites on the poorly oxygenated lake floor. Abundant coprolites are the result of predation on Mesacanthus and small Ischnacanthus, probably by larger Ischnacanthus. Arthropods present include eurypterids (Pterygotus), washed in as near complete exuviae and fragments, and millipeds which were washed in from surrounding terrestrial environments along with plants, of which Parka and Zosterophyllum are common. Bioturbation indicates that conditions were not permanently anoxic during deposition of the laminites.Comparison of our collections with the Mitchell Collection accumulated in the 19th century indicates that Tillywhandland Quarry was the main source of specimens in laminite lithologies labelled ‘Turin Hill’.

Fishes of the Old Red Sandstone and Systemic Boundaries Blossburg, Pennsylvania 1830-1900

1992 ◽  
Vol 11 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Alan Leviton ◽  
Michele Aldrich
Keyword(s):  
New York ◽  
Fish Fauna ◽  
Field Work ◽  
Upper Devonian ◽  
Boundary Problems ◽  
Lower Carboniferous ◽  
Red Sandstone ◽  
Survey Report ◽  
The 19Th Century ◽  
Floodplain Sediments

During the Late Devonian, in what is now northcentral Pennsylvania, slow moving streams meandered across the plain of the "Catskill" Delta. A varied fish fauna lived in these streams, and their remains are entombed in the ancient stream channel and floodplain sediments. In the 1830's, English railroad engineer Richard Cowling Taylor visited the coal mining community of Blossburg and remarked on the analogy between the Old Red Sandstone of England and that found near Blossburg. Not long afterwards, James Hall (1811-1898), best known for his work on Paleozoic invertebrates of New York, also visited Blossburg to clear up vexing boundary problems in the New York formations. He obtained fish scales from the red sandstones, many of which he identified as scales of Holoptychus nobilissimus, a crossopterygian fish described by Louis Agassiz in 1839. In his annual report for 1839 to the New York Legislature, Hall also took note of some large scales, which were unlike any previously described. Under pressure from the Governor, Hall, like the other survey scientists, had to submit timely reports even if studies were incomplete, and he hurriedly described the new scales, referring them to a new genus and species, Sauritolepis taylori. In his final survey report (1843). Hall dealt more fully with the new fish, renaming it Sauripteris taylori based on the fin structure, the significance of which he had not earlier recognized. The Blossburg fishes did not languish in obscurity; James DeKay referred to them in his checklist of fishes of New York, as did Charles Lyell in his 1845 Travels in North America. In 1890 John Strong Newberry placed the fish fossils in the Lower Carboniferous; he also described several new species. Hall's handling of the fossil fish he had before him and, indeed, the reasons for entering Pennsylvania in the first place, are emblematic of the way much science was practiced in the first half of the 19th century. Further, recent field work in the Blossburg area shows Hall's astuteness as a field geologist for he correctly placed the fish in the Upper Devonian, although in this region the Upper Devonian-Lower Carboniferous boundary is not well defined.

The last pteraspids (Vertebrata, Heterostraci): new material from the Middle Devonian of Alberta and Idaho

2020 ◽  
Vol 94 (4) ◽  
pp. 758-772
Author(s):  
David K. Elliott ◽  
Linda S. Lassiter ◽  
Kathryn E. Geyer
Keyword(s):  
Middle Devonian ◽  
New Genus ◽  
New Combination ◽  
Additional Material ◽  
Lower Paleozoic ◽  
Early Devonian ◽  
Red Sandstone ◽  
Large Channel ◽  
New Material ◽  
Paleozoic Rocks

AbstractThis report documents the last pteraspids, (armored, jawless members of the Heterostraci), which are otherwise only known from the Early Devonian of the Old Red Sandstone Continent. Tuberculate pteraspid heterostracans are described from the Middle Devonian beds of two formations in western North America. The late Givetian Yahatinda Formation of Alberta and British Columbia consists of channels cut into lower Paleozoic rocks and represents deposition in marine to littoral environments. Clavulaspis finis (Elliott et al., 2000a) new combination is redescribed from additional material from the Yahatinda Formation and reassigned to the new genus Clavulaspis because the original genus name is invalid. The Eifelian Spring Mountain beds of Idaho consist of a large channel that represents a clastic-dominated estuarine environment. It contains Scutellaspis wilsoni new genus new species, and the previously described species from the Spring Mountain beds is redescribed and reassigned to Ecphymaspis new genus, which was prompted by new material and a review of the validity of the original genus name. Phylogenetic analysis shows that these three new taxa form part of the derived clade Protaspididae.UUID: http://zoobank.org/9cf09b21-cec1-4ce4-bc2b-658d0b515e10

The Boothiaspidinae, a new agnathan subfamily (Heterostraci, Cyathaspididae) from the late Silurian and Early Devonian of the western United States and the Canadian Arctic

2016 ◽  
Vol 90 (6) ◽  
pp. 1212-1224
Author(s):  
David K. Elliott
Keyword(s):  
United States ◽  
New Genus ◽  
Canadian Arctic ◽  
Western United States ◽  
Early Devonian ◽  
Previous Evidence ◽  
Red Sandstone ◽  
The Family ◽  
Close Relationship ◽  
Three New Species

AbstractThree new species of the new genus Phyllonaspis are described from Early Devonian localities in the western United States. Phyllonaspis laevis, P. serratus, and P. taphensis are broad, flattened cyathaspids with lateral brims and fine dermal ornament, that show a close relationship to the cyathaspids Boothiaspis and Alainaspis from the late Silurian and Early Devonian of the Canadian Arctic. These taxa are here accommodated within the new subfamily Boothiaspidinae within the family Cyathaspididae. This relationship supports previous evidence of faunal connection between these two areas and indicates dispersal around the Old Red Sandstone Continent from a center in the Canadian Arctic. Isolated oral plates allow a reconstruction of the oral cover and increase our knowledge of the range of oral structures in this family.

Myriapodous arthropods from the Viséan of East Kirkton, West Lothian, Scotland

1993 ◽  
Vol 84 (3-4) ◽  
pp. 309-316 ◽  
Author(s):  
William A. Shear
Keyword(s):  
Early Carboniferous ◽  
Late Carboniferous ◽  
Early Devonian ◽  
Red Sandstone ◽  
Ground Plan ◽  
Time Gap

ABSTRACTSeveral specimens of myriapodous arthropods have been discovered at the early Carboniferous East Kirkton site near Bathgate, West Lothian, Scotland. None is particularly well preserved, but they are the earliest known Carboniferous myriapods, filling the time gap between the Old Red Sandstone of the early Devonian and the abundant myriapod faunas of the late Carboniferous (Pennsylvanian). One of the specimens, a milliped, provides the earliest evidence for both ozopores (repugnatorial gland openings) and spiracles. A second milliped specimen has some characteristics of the living Order Glomeridesmida, and hence of Enghoff's (1990) ‘ground plan’ of chilognathan millipeds. Aspects of these forms and a third suggest a novel early Carboniferous fauna clearly different from both earlier and later ones. The taxon name ‘Myriapoda’ should be abandoned, since it covers a group now recognised as paraphyletic. ‘Archipolypoda’ is probably synonymous with Order Euphoberiida, Class Diplopoda.

scholarly journals New information on Brindabellaspis stensioi Young, 1980, highlights morphological disparity in Early Devonian placoderms

2018 ◽  
Vol 5 (6) ◽  
pp. 180094 ◽  
Author(s):  
Benedict King ◽  
Gavin C. Young ◽  
John A. Long
Keyword(s):  
Synchrotron Radiation ◽  
New South ◽  
Fish Fauna ◽  
Diverse Range ◽  
Sensory Canal ◽  
Early Devonian ◽  
South Wales ◽  
New Information ◽  
Anterior Position ◽  
Arch Structures

Acid-prepared specimens of the placoderm Brindabellaspis stensioi (Early Devonian of New South Wales, Australia) revealed placoderm endocranial anatomy in unprecedented detail. Brindabellaspis has become a key taxon in discussions of early gnathostome phylogeny, and the question of placoderm monophyly versus paraphyly. The anterior orientation of the facial nerve and related hyoid arch structures in this taxon resemble fossil osteostracans (jawless vertebrates) rather than other early gnathostomes. New specimens of Brindabellaspis now reveal the previously unknown anterior region of the skull, including an exceptionally elongate premedian bone forming a long rostrum, supported by a thin extension of the postethmo-occipital unit of the braincase. Lateral overlap surfaces indicate an unusual anterior position for the jaws. Digital rendering of a synchrotron radiation scan reveals a uniquely specialized ethmoid commissure sensory canal, doubled back and fused into a midline canal. The visceral surface of the premedian bone has a plexus of perichondral bone canals. An updated skull roof reconstruction of Brindabellaspis adds to the highly variable dermal skull patterns of the probably non-monophyletic ‘acanthothoracids'. The unusual morphology revealed by the new specimens suggests that the earliest known reef fish fauna contained a diverse range of fishes with specialized ecological roles.

Spore assemblages from the Lower Devonian ‘Lower Old Red Sandstone’ deposits of Arran, Scotland

2009 ◽  
Vol 100 (04) ◽  
pp. 391-397 ◽  
Author(s):  
Charles H. Wellman
Keyword(s):  
Lower Devonian ◽  
Early Devonian ◽  
Red Sandstone ◽  
Extensive Sequence

ABSTRACTDispersed spore assemblages have been recovered from the Am Binnein Sandstones from the upper part of the ‘Lower Old Red Sandstone’ sequence on the island of Arran, Scotland. The spore assemblages belong with theEmphanisporites annulatus–Camarozonotriletes sextantii(AS) Spore Assemblage Biozone (SAB), indicating an Early Devonian, Emsian (but not earliest Emsian or latest Emsian) age. This is the first reliable age constraint for the ‘Lower Old Red Sandstone’ of Arran, and enables correlation with the more extensive sequence developed on the mainland in the Midland Valley of Scotland. The Am Binnein Sandstones are confirmed as correlatives of the Strathmore Group.

Role of the Midland Valley of Scotland in the Caledonian orogeny

1983 ◽  
Vol 74 (3) ◽  
pp. 119-136 ◽  
Author(s):  
B. J. Bluck
Keyword(s):  
Volcanic Rocks ◽  
Substantial Contribution ◽  
Volcanic Arc ◽  
Early Devonian ◽  
Red Sandstone ◽  
Metamorphic Basement ◽  
Caledonian Orogeny ◽  
Southward Extension ◽  
Trench Slope

ABSTRACTThe Midland Valley of Scotland was an arc–interarc region during most of Ordovician—Devonian time. This arc terrane extends beneath the allochthonous Southern Uplands and probably beneath the southern Highlands. Models of Caledonian plate tectonism which regard the Midland Valley as a fore-arc basin are rejected principally on the grounds that (i) the Ordovician sequence at Girvan, in the very SW of the Midland Valley, was generated in a proximal fore-arc basin to the immediate S of a contemporaneous plutonic–volcanic arc, and (ii) the source for Silurian sediments in the southern part of the Midland Valley could not have been a rising trench-slope-break, but igneous basement and conglomerates with clasts of metamorphic basement, i.e. the southward extension of the Midland Valley.The Midland Valley arc first comprised mainly plutonic rocks, some of which may have been basic but most of which were certainly granitic. Little is known of the ages of volcanic clasts in Silurian conglomerates (this time may have been a period of relative volcanic quiescence), but the Silurian–Devonian sequence is considered to have formed in an interarc basin which, like many other basins of this kind, began as marine (Early Silurian) and ended as fluvial (Devonian). At this final Silurian–Devonian stage, the Midland Valley arc was dominated by effusive rocks which made a substantial contribution to the sediments.In this interpretation, the present Old Red Sandstone volcanic rocks are seen as the final stage of a volcanic arc which occupied the position of the present Midland Valley from at least Llanvirn to Early Devonian time.

Palaeoecology of the Viséan of East Kirkton, West Lothian, Scotland

1993 ◽  
Vol 84 (3-4) ◽  
pp. 417-425 ◽  
Author(s):  
E. N. K. Clarkson ◽  
A. R. Milner ◽  
M. I. Coates
Keyword(s):  
Volcanic Activity ◽  
Shallow Lake ◽  
Water Body ◽  
Oil Shale ◽  
Hot Spring ◽  
Fish Fauna ◽  
Black Shales ◽  
Aquatic Life ◽  
History Of ◽  
The Many

ABSTRACTThe Viséan sequence at East Kirkton was deposited in a shallow lake, set within a richly vegetated landscape formed of volcanic cones a few hundred metres high. There was little volcanic activity, however, while the lake existed, and the many tuff horizons within the sequence were washed in during weathering. The lake may have been generally cool, though of unusual water chemistry, as a result of which the spherulitic East Kirkton Limestone precipitated. At times, however, water temperatures may have risen sharply through localised hot-spring activity; both factors deterred ‘normal’ aquatic life.The bulk of the preserved biota consists of plants (permineralisations and compressions) and dominantly land-living animals, including the oldest terrestrial tetrapods (amphibians and reptiliomorphs), large terrestrial-aquatic eurypterids, the first harvestman and rare millipedes. All these animals lived close to the lake, in a fire-prone forest dominated by gymnosperms and pteridosperms.At a late stage in the history of the lake, deposition of spherulitic limestones was replaced by black shales, bearing a ‘standard’ Oil-Shale fish fauna, suggesting that the isolated lake had linked with a larger fish-bearing water body. This is coupled with a shift to a lycopod-dominated flora and may indicate a climatic change to wetter conditions. Finally the lake silted up with tuff, ending an existence of only a few tens of thousands of years.

Precambrian and Palaeozoic rocks of the Inner Hebrides

1983 ◽  
Vol 83 ◽  
pp. 31-45
Author(s):  
R. Anderton ◽  
D. R. Bowes
Keyword(s):  
Small Area ◽  
Early Devonian ◽  
Red Sandstone ◽  
North West ◽  
Late Cambrian ◽  
Thrust Zone ◽  
Lower Palaeozoic ◽  
Caledonian Orogeny ◽  
Peripheral Areas ◽  
Mountain Chain

SynopsisThe Lewisian complex, which forms the continental basement to north-west Scotland, crops out on the Inner Hebridean islands of Rona, Raasay, Skye, Coll, Tiree, Iona and Islay. Upon this basement, four major rock successions were deposited before the Caledonian orogeny. The upper Precambrian Moine assemblage forms only a small area of metamorphosed rocks on Mull but the c. 790 m.y. (million year) old Torridonian sediments are found on Raasay, Scalpay. the Sleat of Skye, Soay and Rhum. The upper Precambrian to Cambrian Dal radian Supergroup dominates Islay, Jura, Gigha and the islands of the Firth of Lome whilst also forming a partial rim around the Tertiary Northern granite in Arran. Other Precambrian rocks of uncertain affinity are found on Islay, Oronsay, Colonsay and Iona. Cambro-Ordovician sediments are found on Skye where they have been partially metamorphosed by Tertiary intrusions.South-east of the Moine thrust zone, the Precambrian and lower Palaeozoic rocks were deformed and metamorphosed during the late Cambrian to early Devonian Caledonian orogeny which resulted in the development of the Caledonian mountain chain. Subsequently, Scotland north-west of the Highland Boundary fault has tended to persist as a land area undergoing erosion with sedimentation restricted to peripheral areas now preserved around the present coast. Upper Palaeozoic rocks are therefore only well represented on Arran although Old Red Sandstone (Devonian) sediments are found in the Firth of Lome and a very small area of possible Permian rocks occurs on Islay.

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