The organic-walled microfossil Mispertonia desiccata gen. et sp. nov. is described from the Arnsbergian (Mississippian, Early Carboniferous) of borehole Kirby Misperton-1, North Yorkshire, UK. This species includes thin-walled, originally spherical or sub-spherical vesicles; with a single polygonal field surrounded by a rim and a thickened collar which is interrupted by grooves radiating out from the angles of the polygonal field. The form is recovered from marine strata of the Silsden Formation equivalent, but is not necessarily of marine origin. Similar specimens, here synonymised with M. desiccata , are known from the non-marine Late Permian or Early Triassic of India.

A detailed account of assemblages of megaspores and large pollen grains from the mid-Bolsovian to late Asturian Warwickshire Group (Winterbourne, Pennant Sandstone and Grovesend formations) of the Bristol Coalfield is presented. The megaspore assemblages show certain similarities to those from the well-documented, and partly coeval, sequence in the nearby Forest of Dean Coalfield. However, the Bristol Coalfield megaspore assemblages are generally less diverse. We consider the palaeoecological implications of the megaspore assemblages and conclude that differing depositional settings had different vegetational successions (including differences in the composition and diversity of megaspore-producing plants). A consideration of megaspore biostratigraphy suggests that the uppermost Pennant Sandstone Formation may be of early Asturian age, suggesting that the postulated gap between the Pennant Sandstone Formation and overlying Grovesend Formation is smaller than previously suggested. We also report the first European occurrence of the large enigmatic pteridosperm pollen grain Parasporites maccabei Schopf, 1938.

Examination of cored borehole sections of Pennsylvanian sediments in the Machrihanish Coalfield on Kintyre and samples from coastal exposures at Inninmore Bay on the Sound of Mull, demonstrate the existence of Westphalian (Langsettian to Bolsovian) sediments in both close proximity to the Highland Boundary Fault zone and in isolated outliers within the western parts of the Scottish Highlands. Earlier studies suggested a Duckmantian to Bolsovian age for the Inninmore Bay sections and the investigation of material from new sections in the area confirms this stratigraphical range. The borehole sections in the Machrihanish Coalfield demonstrate the unconformable relationship between the probable Namurian to Westphalian sediments of the Scottish Coal Measures Group and the underlying early Namurian Limestone Coal Formation. In addition to rich assemblages of western European miospore taxa, the Machrihanish populations contain examples of species such as Columinisporites ovalis, Paleospora fragila, Spackmanites irregularis and Vestispora colchesterensis which are characteristic of North American assemblages. The distinctive species Playfordiaspora cancellosa is reported from the British Carboniferous.

We describe moderately diverse but extremely widespread calcified plant assemblages from the Pennsylvanian (mid/late Bolsovian–Asturian) Pennant Sandstone Formation (Warwickshire Group) of southern Britain, based on museum collections and new field discoveries. Fossils are documented from 21 sites where they comprise allochthonous accumulations within channel-lag conglomerate and coarse-grained sandstone facies of large, braided river channels draining the Variscan Orogen. Assemblages are dominated by cordaitaleans (87% of total, Amyelon, Mesoxylon, Dadoxylon), with a few tree-ferns (7%, Psaronius), and rare pteridosperms (1%, Myeloxylon), sphenopsids (2.5%, Arthropitys) and lycopsids (2.5%, ‘Lepidodendron’). These fossils clearly derived from a different plant community to those found in the coal seams (mixed fern/lycopsid-dominated based on palynofloras) and roof shales (pteridosperm-dominated based on megafloral adpressions), which occur between the fluvial sandstone deposits. Two competing hypotheses to explain these compositional differences are that (1) permineralised plants grew in extra-basinal settings adjacent to areas of Coal Forest or (2) permineralised plants grew on lowland interfluves during times of drier climate when Coal Forests had temporarily retreated. Data are currently insufficient to test between these hypotheses although the calcified preservational mode suggests burial under seasonally dry conditions.

The Bristol Coalfield of southwest Britain, although intensively studied in the early history of palaeobotany, has received little attention for 75years. Here we review the palaeobotany of the mid-Bolsovian to Cantabrian (Moscovian) Warwickshire Group of the Bristol Coalfield, which comprises, from base to top, the Winterbourne, Pennant Sandstone and Grovesend formations. Based on an investigation of all available adpression and sandstone-cast plant assemblages in a facies context, we develop a new system of biostratigraphical zonation and elucidate palaeoecology. Our key findings are: (1) Using the new biozonation we identify a stratigraphical gap encompassing the early to mid-Asturian, occurring between the mid- and late Bolsovian Pennant Sandstone and the late Asturian Grovesend formations. This tectonic-induced stratigraphical gap most likely relates to the Leonian Phase of the Variscan uplift and can be correlated with contemporaneous hiatuses in the South Wales and other European coalfields. (2) We recognise a diverse patchwork of plant communities as follows: Peat mires of the Bolsovian Winterbourne and Pennant Sandstone formations were dominated by lepidodendrids and ferns, but were replaced by tree-fern and fern-dominated mires in the late Asturian Grovesend Formation. Clastic swamps fringed these mires and were characterised by a diversity of pteridosperm, calamitaleans and ferns. Riparian communities associated with the coarse-grained deposits of large-scale braided fluvial systems that vertically alternate with the coals/shales, variously comprised Sigillaria, calamitaleans and cordaitaleans, with pockets of pteridosperms and calamitaleans surrounding channel abandonments. In addition, large cordaitaleans were common in drier interfluve and/or hinterland areas. Switching between stable mire communities and disturbed fluvial communities either reflects autocyclic channel switching or allocyclic alternations driven by climate change.

Pennsylvanian dryland plant communities are poorly known compared to those of coeval wetlands – a function of taphonomic megabias. Here we describe a new example from the mid- to late Bolsovian Winterbourne Formation of Staplehill, Bristol, southern Britain based on a re-examination of historical fossil material. These fossils, collected by Herbert Bolton in 1905/6, initially studied by Dennis Lillie in 1908/9, and later re-assessed by Robert Crookall in 1926/7, were thought to have been lost until their recent discovery in an unaccessioned repository at the British Geological Survey. The calcified assemblage, which we describe and fully illustrate for the first time, is dominated by cordaitalean remains (Dadoxylon trunks, Amyelon roots and Mesoxylon aerial axes), together with a single medullosan pteridosperm (Sutcliffia lillieii) and an indeterminate lycopsid (possibly sigillarian). Locality and facies data collected at the time of the original discovery, combined with new facies data from boreholes, limited outcrops, and sediments adhering to the fossils, demonstrate that this assemblage was deposited in a well-drained alluvial plain environment. Three independent lines of evidence indicate a seasonal subhumid tropical climate: (1) the breccia-conglomerate unit that hosts the fossil assemblage is interpreted as the deposits of a somewhat flashy alluvial drainage, (2) carbonate rhizoconcretions reworked into the conglomerate with the water-worn fossils are interpreted as remains of caliche paleosols that develop only under conditions of seasonal water deficit, and (3) erratic growth interruptions in the fossil woods indicate the plants grew under aperiodic water-stressed conditions. These findings provide further evidence that gymnosperm-dominated dryland ecosystems were more abundant and widespread in the Pennsylvanian tropics than previously recognized.

The Scottish Coal Measures Group of the Midland Valley was the proving ground for much of the pioneering palynological work that laid the foundations of European Carboniferous palynostratigraphy (e.g. Knox, 1945-1946, Smith and Butterworth, 1967). This study focuses on two small, relatively unstudied areas of the Midland Valley and western Scotland; the Machrihanish Coalfield on the Kintyre peninsula and Inninmore Bay on Movern. In addition to re-evaluating previously collected material (Love and Neves, 1964), new samples were acquired from two boreholes and newly discovered outcrop sections. Previous palynological work suggested a Duckmantian to Bolsovian age for the Inninmore Bay sections, which is confirmed by this re-evaluation and by investigations of new sections. Re-evaluation of plant fossil registers from MacGregor and Mason (1934) implies a mid-Duckmantian to early Bolsovian age; in concordance with the palynological age range. Most of the Bolsovian miospore assemblages are dominated by diverse saccate pollen taxa and associations of Auroraspora spp., Colatisporites spp., Knoxisporites spp., Verucosisporites spp. and Convolutispora spp. These assemblages probably represent a “hinterland” vegetation reflecting relatively dry palaeoenvironemnts. Duckmantian assemblages are more typical of coal measures reflecting relatively wet palaeoenvironments. Miospores from boreholes in the Machrihanish Coalfield prove Langsettian to early Bolsovian Scottish Coal Measures Group, overlying a probable Namurian aged sequence of interbedded basaltic lavas and sedimentary units likely representing the Passage Formation. The unconformable nature of the underlying late Visean to early Namurian Limestone Coal and Upper Limestone formations is also demonstrated. In addition to rich assemblages of western European taxa, the Machrihanish populations contain examples of miospore genera such Paleospora and Columinisporites that are characteristic of North America .