Lower Carboniferous Of Scotland Research Articles

The distribution of Schramocaris (Eumalacostraca, Crustacea) along the northwestern coast of the Rheic Ocean during the Lower Carboniferous

ABSTRACTTwo new species of Schramocaris from the Viséan, Lower Carboniferous of Scotland and eastern Canada extend the range and distribution of this crustacean along the northwestern coast of the Rheic Ocean. New species from Glencartholm, southern Scotland and Upperton, New Brunswick, Canada represents the first recognised occurrence of this genus in Scotland and Canada. The Scottish species is here named S. clarksoni; it lacks the rugosity of the carinae of Schramocaris gilljonesorum, but has the same relative position of the carinae, as well as similar characteristics of the pleon, such as the relative lengths of the somites and the shape of the telson. The Canadian species is named Schramocaris matthewi on the basis of the papillations on the cuticle and robust second carinae of the carapace. The deposits at both these localities are that of a shallow marine argillaceous environment, although the Glencartholm deposit contains more lime. Schramocaris has previously only been known from the Avon Group (Hastarian) of the Forest of Dean, England.

Evidence that Early Carboniferous ostracods colonised coastal flood plain brackish water environments

A study of the stable isotope composition ( δ 18O, δ 13C) of biogenic (ostracod, mollusc) and authigenic carbonates in the Ballagan Formation, Lower Carboniferous of Scotland, coupled with evidence from sedimentology and associated fossil fauna and flora, supports the argument that this formation was deposited in a coastal flood plain setting, in brackish (0.5 < 30‰ NaCl) and hypersaline (> 40‰ NaCl) waters, but in the absence of persistent normal marine conditions. The oxygen isotope data from the Ballagan Formation divide into three clusters: a diagenetic field defined by low δ 18O (< − 11‰ VPDB); an intermediary field ( δ 18O − 11‰ to − 9‰) composed of a mixture of known primary and secondary (diagenetic) carbonates; and samples within the range of − 9‰ to − 4‰ which, as far as we can ascertain, are largely unaltered. No samples give typical Early Carboniferous δ 18O marine values. Average marine carbonates from Europe have δ 18O between − 4‰ to − 3‰. The Ballagan Formation carbonates were probably deposited in evaporated freshwater and/or brackish water. This conclusion is supported by the presence of evaporites (gypsum, anhydrite, halite pseudomorphs) and common desiccation-cracked mudstone surfaces throughout the Ballagan Formation, suggesting conditions of fluctuating salinity in ephemeral bodies of water. The stable isotope data support the notion that the ostracod assemblages of the Ballagan Formation were colonising brackish water and hypersaline ecologies on a coastal flood plain during the Early Carboniferous, a stage of development that may have encouraged their colonisation of fully non-marine (limnetic) environments during the later Carboniferous. The ostracods include cytherellacean and kloedenellacean species known from marginal marine sites elsewhere, but probably tolerant of brackish water, podocopid species such as ‘ Bythocypris’ aequalis that may have been adapted for brackish water settings on coastal flood plains (ephemeral lakes and lagoons), and paraparchitacean-dominated assemblages that may signal harsh (hypersaline or desiccating) environments.

The tetrapod Caerorhachis bairdi Holmes and Carroll from the Lower Carboniferous of Scotland

The tetrapod Caerorhachis bairdi Holmes and Carroll from the Lower Carboniferous of Scotland

A Reinvestigation of Stenomyelon from the Late Tournaisian of Scotland

Three species of Stenomyelon identified from anatomically preserved stems with attached petiole bases from the Lower Carboniferous of Scotland were reinvestigated. Stenomyelon tuedianum and Stenomyelon heterangioides are conspecific and form the basis for a new concept of S. tuedianum, including a unique pattern of petiolar bundle development and possession of adventitious roots. Changes from a "heterangioides"-type of anatomy with medullated protostele and mesarch protoxylem strands to a "tuedianum"-type characterized by solid protostele and exarch protoxylem are postulated to correspond to apoxogenetic phases of growth. Contrary to lycopsids, sphenopsids, and progymnosperms studied so far, steles of S. tuedianum axes do not show any changes in the number of protoxylem strands related to ontogeny. Stenomyelon primaevum differs from S. tuedianum by a stele with slender ribs, protoxylem strands occurring deeper in the stele, and a simpler pattern of formation of petiolar bundles. Stelar architectures of S tuedianum and S. primaevum are discussed according to the sympodial view of seed plants proposed by Beek and the alternative foliar interpretation developed by Stein. Hormone models using positions of protoxylem strands to mark regions of high hormone concentration predict with a good degree of accuracy the shape of the steles and occurrence of parenchyma between primary and secondary xylem in both species as well as number and position of radiate bands of parenchyma in S. tuedianum

Fossil actinomycete in Eocene-Oligocene Dominican amber

Actinomycetes are Gram-positive prokaryotes that tend to form branching and fragmenting filaments, which in some groups form a sizable mycelium. They make up a large and important part of modern terrestrial microfloras but are not known extensively as fossils, although they have a long fossil history. Actinomycete-like fossils appear several times in the Precambrian: in the middle Precambrian Gowganda Formation of Ontario (Jackson, 1967), in the 2.0 Ga Gunflint Chert of Ontario (Lanier, 1987), and possibly in a lichen-like symbiosis in the 2.8 Ga Witwatersrand rocks of South Africa (Hallbauer and Van Warmelo, 1974), among others. Direct fossil evidence of actinomycetes is very rare in the Phanerozoic, and some “fossil” actinomycetes may be later contaminants (Knoll, 1977; Smoot and Taylor, 1983). Hyphae identified as actinomycetes are known from rod-like bodies identified as nematodes inside a decaying scorpion from the lower Carboniferous of Scotland (Stoermer, 1964), and from the interior of fern phloem cells from the Pennsylvanian (Smoot and Taylor, 1983). UnmineralizedActinomyces-like cells are known from calcite in bituminous lake-bed sediments from the early Cretaceous of Nevada (Bradley, 1963), and similar, poorly preserved fossils of a form calledActinomyciteshave been reported from the Jurassic of Scotland (Ellis, 1915). Actinorhizal nodules, formed by actinomycetes symbiotic with plant roots, have been described from the late Pleistocene (Baker and Miller, 1980).

A juvenile adelogyrinid (Amphibia: Lepospondyli) from the Namurian of Scotland

ABSTRACT A tiny amphibian specimen from the Lower Carboniferous of Scotland is identified as a juvenile adelogyrinid. It is approximately 10 cm in length, including the skull and approximately 70 vertebrae. A clavicle is present, but there is no trace of the pelvic girdle or any limb elements. The centra are fully formed but are very thin-walled cylinders. The anterior ribs bear conspicuous uncinate processes. The anatomy of this individual emphasizes the distinctive nature of adelogyrinids, and shows no clearly definable synapomorphies linking the adelogyrinids with any other particular group of Paleozoic tetrapods.

Melissiotheca: a new pteridosperm pollen organ from the Lower Carboniferous of Scotland

Melissiotheca is based on fusainized pollen organs of pteridospermous affinities which occur abundantly in an Upper Visean limestone at Kingswood, near Pettycur (Scotland). The new species is a pedicellate synangium composed of 50–150 sporangia each of which is embedded at its base in a parenchymatous cushion divided into lobes. The sporangia are fused along their proximal half but are free distally. Dehiscence is longitudinal. Each sporangium is supplied at its base by a single vascular strand. Prepollen is small, spherical and trilete with a rugulate exine. In ultrastructure, the nexine appears homogeneous; the sexine shows internal sculpture of granae and rod elements. Melissiotheca has not been assigned to any family, but it shows many affinities with pollen organs attributed to the Lyginopteridaceae.

Diversification of early ferns

SynopsisA review of current knowledge of early fern evolution is presented including new data on age, morphology and anatomy with two diagrams summarising the early diversification of cauline and foliar anatomy and of the reproductive structures. The relationships and even the attribution of some Devonian taxa to the ferns is questioned whilst most of the Carboniferous coenopterids are considered indisputable ferns, some of them being related to modern filicaleans. The discovery, in the Lower Carboniferous of Scotland, of diverse annulate filicalean sporangia suggests an earlier (Tournaisian) radiation of true ferns than was previously assumed.

Lower Carboniferous biota of Glencartholm, Eskdale, Dumfriesshire

Synopsis The unusual biota of the Glencartholm Volcanic Beds, Lower Carboniferous of Scotland is restudied in the first overall treatment since the turn of the century. Examination of the large collections now housed in the IGS Edinburgh and the Royal Scottish Museum afforded a complete list of the biota (some species never having been previously recorded from Glencartholm) and relative proportions among species. Selective diagenesis has occurred, calcareous fossils being dissolved, but organic/phosphatic forms preserved. Attempts to re-excavate the original site proved only partially productive; however, a new locality for the Glencartholm biota is herein recorded.

2.—Palynological Correlations within the Lower Carboniferous of Scotland and Northern England

SynopsisThis paper provides a comprehensive account of the distribution of miospore species which are considered to be stratigraphically significant in the Dinantian (Calciferous Sandstone Measures and Lower Limestone Group) of the Midland Valley of Scotland. Five miospore concurrent range zones are recognised in these beds:Tripartites vetustus—Rotaspora fracta (VF) ZoneRaistrickia nigra—Triquitrites marginatus (NM) ZonePerotrilites tessellatus—Schulzospora campyloptera (TC) ZoneLycospora pusilla (Pu) ZoneSchopfites claviger—Auroraspora macra (CM) ZoneThe distribution of these zones in the sections studied provides a method of correlation in a series of rocks, which are largely of non-marine origin and notable for their lack of stratigraphically useful macrofossils and for marked variations in facies and thickness. The zones have also been proved in sections of Lower Carboniferous rocks in the Northumbrian trough, thereby providing a potential method of correlation between the two areas.Two new genera, Colatisporites and Biannulatisphaerites, are described and one Tricidarisporites emended. Fifteen new species and one new type are described, three species recombined and three emended. Representative assemblages of the miospore zones are illustrated.

AN ADELOGYRINID LEPOSPONDYL AMPHIBIAN FROM THE UPPER CARBONIFEROUS

A new genus of the Paleozoic amphibian subclass Lepospondyli is described. It is a member of the family Adelogyrinidae, orginally based on three specimens from the Lower Carboniferous of Scotland. Further information provided by this genus forms the basis for consideration of the relationships of the adelogyrinids to other lepospondyls. Adelogyrinids might be considered aberrant members of the Microsauria or Nectridea, but may better be thought of as a separate group. They show little evidence of affinity with the lysorophids. Evidence is presented suggesting that lepospondyl centra may be homologous with the intercentra of labyrinthodonts.

Aragonitic Fossils in the Lower Carboniferous of Scotland

ALTHOUGH many invertebrates form skeletons partly or wholly of aragonite, this normally inverts to calcite within a geologically negligible period of time, a few tens of thousands of years at the most1. Indeed, more than 50 per cent of the aragonite laid down by some of the marine invertebrates studied by Lowenstam2 inverted to calcite within a year. As the geothermal gradient lies completely within the stability field of calcite it has been maintained that aragonite within buried sediments could exist only in peculiar local conditions of high hydrostatic pressure and moderate temperature3. Aragonite in rocks of a respectable age may therefore be presumed rare, and any record of such an occurrence is of interest both because of the problems posed by the preservation of this metastable mineral and the desirability of obtaining unaltered shells for palaeo-ecological studies.

XXI.—Levicaulis arranensis, gen. et sp. nov., A Lycopsid Axis from the Lower Carboniferous of Scotland

SynopsisA Large number of structurally preserved lycopsid axes from the Lower Carboniferous of Scotland are described and designated as a new genus and species. A comparison of this genus with other lycopsids is followed by a discussion of the development of the secondary cortex, and several other interesting structural features.

LXII.—On Lepidocarpon waltoni, sp. n., from the Lower Carboniferous of Scotland

(1952). LXII.—On Lepidocarpon waltoni, sp. n., from the Lower Carboniferous of Scotland. Annals and Magazine of Natural History: Vol. 5, No. 54, pp. 572-582.

A New Fossil Gymnospermous 'Ovary'

THE discovery of a new type of many-seeded fruit body from the Lower Carboniferous of Scotland is a matter of more than local palæobotanical The publication by Prof. John Walton of the description of Calathospermum scoticum (Tran. Soc. Edin., 61, 719 ; 1949), which has since the preliminary account in 19401, therefore most welcome, although it is difficult to withhold a protest that any learned society, so long after the end of the War, should subject important scientific work to the treatment recorded in the superscription "MS. received May 10th, 1947. Read May 3rd, 1948. Issued separately Feb. llth, 1949."

A New Cupule from the Lower Carboniferous of Scotland

A New Cupule from the Lower Carboniferous of Scotland

III.—On a Femur of Reptilian Type from the Lower Carboniferous of Scotland

Whilst looking over the private collection of fossil fishes made by the late Dr. R. H. Traquair, I found a small tetrapod femur. This bore no label of any kind, but was included in a series of remains of Dipnoi from the Lower Carboniferous of Scotland. The texture of the bone is not unlike that of Ctenodus, and was no doubt the reason of its place in the collection.The very small piece of matrix which is preserved is identical with that of some of the fish from the No. 2 Ironstone, Loanhead, and differs from any other fish-bearing matrix that I know in Britain. [Any one with experience of Carboniferous fishes will recognize that it is usually fairly easy to identify the important localities (the Loanhead ironstones, the various Staffordshire ironstones, etc.) by inspection of the matrix.] Despite the fact that it was not localized, I think that the probability of its being from the Loanhead ironstones is sufficient to justify a description.

XVII.—On the Primary Structure of certain Palæozoic Stems with the Dadoxylon Type of Wood

In a Note published in the Annals of Botany for December 1899, I gave some account of the structure of two stems from the Lower Carboniferous of Scotland, provisionally named Araucarioxylon fasciculare, sp. nov., and A. antiquum, Kr. (Witham, sp.).In the present paper these stems are described fully, with the help of illustrations, and others, presenting similar points of interest, are added. The species dealt with are the following:—Calamopitys fascicularis (Araucarioxylon fasciculare of the Note).Calamopitys beinertiana (Araucarioxylon beinertianum, Kr.), (Göpp., sp.).Pitys antiqua, Witham (Araucarioxylon antiquum, Kr. of the Note).Pitys Withami (Pinites Withami, Lindl. &amp; Hutt.).Pitys primœva, Witham.Dadoxylon Spenceri, sp. nov.