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.     

New observations on the Lower Carboniferous pteridosperm Diplopteridium Walton and an associated synangiate organ

New material of Diplopteridium holdenii is described from the Drybook Sandstone assemblage of Upper Visean (Middle Mississippian) age at Puddlebrook, Gloucestershire. Vegetative leaves consist of bifurcate fronds which are pinnately divided and terminate in narrow pinnule segments. The fronds are arranged spirally in terminal crowns on a narrow, spindly axis. Fertile leaves consist of fronds which bear a median, dichotomous branchlet which gives rise to reflexed, bilaterally symmetrical cupules. One specimen demonstrates that a single fertile crown consisted of cupulate and vegetative fronds. The detailed morphology of the cupules is reconstructed from compression/impression and fusainized material from both attached and isolated units. An isotomously branched synangiate organ is also described from the locality. The synangiate organ is assigned to a new genus and species. A comparison of D. holdenii and this synangiate organ with Diplopteridium teilianum from north Wales and Sphenopteris bifida and Sphenopteris affine from northern England and Scotland, provides indirect evidence that the synangiate organ may have belonged to D. holdenii . Bifurcate and trifurcate fronds associated with dichotomous branchlets bearing either synangial or cupulate structures was a common association in the Visean compression assemblages of Great Britain.     

A new lycopod, Novgorodendron conophorum gen. et sp. nov., from the Lower Carboniferous of the Moscow Syneclise

A new lycopod, Novgorodendron conophorum gen. et sp. nov., is described from the Upper Visean deposits of the Kamenka River, near the town of Borovichi (Novgorod Region). The morphology of the leaf cushions of the new plant implies its intermediate position between the families Sublepidodendraceae Chaloner et Boureau and Lepidodendraceae Endlicher. The bases of the leaf cushions have peculiar conical appendages, a previously unknown morphological feature not recorded from other lycopods. We propose the term basal conical appendages for them. The interpretation of some epidermal elements in the leaf cushions of the Lepidodendraceae is revised. The structures of the leaf cushions that were previously treated as either stomata or cells with cystoliths are shown to be sunken multicellular trichomes.     

A new microsporangiate organ from the Lower Carboniferous of the Novgorod Region,Russia

A new species of the genus Telangiopsis, T. nonnae O. Orlova et Zavialova, was described on the basis of a microsporangiate organ from the Lower Carboniferous deposits of the Novgorod Region. The morphology of branching fertile axes, synangia, and sporangia was thoroughly studied. The three-dimensional system of fertile axes branches monopodially; ultimate axes bear numerous connivent bunches of synangia, which consist of three to six basally fused elongated ovate sporangia. The morphology and ultrastructure of prepollen grains were studied, which were extracted from the rock matrix surrounding the sporangia. The two-layered exine includes a well-developed endexine and an alveolate ectexine, with one-three rows of large thin-walled alveolae. The new species was compared with other Early Carboniferous microsporangiate organs.     

Enigmatic Fossils from the Lower Carboniferous Shrimp Bed,Granton, Scotland

The Lower Carboniferous (Visean) Granton Lagerstätte (Edinburgh, Scotland) is principally known for the discovery of the conodont animal, but has also yielded numerous crustaceans and other faunas. Here we report on small branching colonies, reaching 10 mm in length. They are small, erect, arborescent, and irregularly branched with predominant monopodial and dichotomous growth. They bud in a single plane. In one specimen the wall microstructure is well preserved and it is composed of evenly spaced, linear fibers, running parallel to the axis of the stems, and connected by transverse bars. We discuss possible biological affinities of these organisms; we consider algal, poriferan, hydrozoan and bryozoan affinities. The general pattern of branching, presence of fan-like structures (interpreted here as possible gonophores) and microstructure suggests affinity to Hydrozoa, affinity to non-calcifying algae is less likely. Assuming hydrozoan nature; the microstructure might suggest affinities with the extant family Solanderiidae Marshall, 1892 that possess an internal chitinous skeleton. The EDS analysis shows that fossils discussed here are preserved as phosphates. The skeletons were probably not mineralized, the presence of phosphorus suggests that the colonies were originally composed of chitin. We describe these organisms as Caledonicratis caridum gen. et sp. nov. (Solanderiidae?, Capitata?). Colonies of C. caridum gen et. sp. nov. sometimes encrust the exuviae of crustaceans, which very probably lived in fresh to brackish water thus indicating a likely habitat of Caledonicratis.     

An enigmatic chordate from the Lower Carboniferous Granton 'shrimp-bed' of the Edinburgh district, Scotland

A new soft-bodied chordate, Conopiscius clarki gen. et sp. nov., with V-shaped scales covering the trunk, and a pair of cone-shaped structures in the head, is described from the Lower Carboniferous of Granton, Edinburgh. It occurs in the 'shrimp-bed' which, although dominated by eumalacostracan crustaceans, has also yielded exceptionally preserved examples of other taxa including the soft parts of conodonts. The new animal may represent a jawless craniate with affinities to Jamoytius. The parallels between this and other faunas yielding similar chordates (e.g. Jamoytius ) may be taphonomic rather than environmental.     

Lower Carboniferous (middle Visean) foraminifers and algae from an interior sea,Southern Carnarvon Basin,Australia

A moderate diversity biota of foraminifers, algae and calcareous microproblematica is recorded from the Lower Carboniferous Yindagindy Formation within the intracratonic Southern Carnarvon Basin in Western Australia. Very shallow metahaline to hypersaline conditions are suggested. The palaeobotanical components are sporadic calcitarcha, tuberitinaceans, codiaceans Orthriosiphon? sp. 1, dasycladaleans? Koninckopora tenuiramosa, and algosponges Issinella devonica, Serrisinella cf. serrensis, Issinella? sp. 1, Kamaena cf. awirsi, Proninella? sp. and Stacheoides spp. The foraminiferal assemblage is dominated by a new koktjubinid taxon: Praekoktjubina yindagindyensis nov. gen., nov. sp. Subordinate associated foraminifers are more sporadic Salpingothurammina? sp. 1, Plectinopsis michelseni nov. gen., nov. sp., Rectopravina multifida nov. gen., nov. sp. (with 4 morphotypes), and scarce Endothyra spp. Despite many of these taxa being endemic, a middle Visean age is probable, based on: (1) the maximum global geographic extent of K. tenuiramosa reached during the middle Visean, (2) the disappearance of Plectinopsis nov. gen. in Palaeotethys and the Urals, and (3) the first occurrence of Praekoktjubina nov. gen. in Palaeotethys. An age no older than the middle Visean is supported by sparse conodonts from the Formation and comparison to episodes of carbonate deposition in the Bonaparte Basin, further north in the East Gondwana rift system. Absence of middle Visean archaediscoids may be due to high salinity. The following algal and foraminiferal families and superfamilies are emended: Scribroporellaceae (a lectotype is selected for Orthriosiphon saskatchewanense); Palaeospiroplectamminidae (due to the creation of Plectinopsis nov. gen.); Haplophragminoidea (due to the creation of Rectopravina nov. gen.); and Globivalvulinoidea and Koktjubinidae (due to the creation of Praekoktjubina nov. gen.).     

The first tomopterid, a polychaete from the Carboniferous of Scotland

Briggs, Derek E. G. & Clarkson, Euan N. K. 1987 07 15: The first tomopterid, a polychaete from the carboniferous of Scotland.
The first known example of a fossil tomopterid, Eotomopteris aldridgei , is described from the Lower Carboniferous of Granton, Edinburgh. The head bears tentacular cirri, and the trunk preserves evidence of at least 20 pairs of parapodia. The polychaete is associated with other soft-bodied and lightly skeletalized organisms including crustaceans, conodonts, an additional chordate, and branching structures which resemble hydroids. It is similar to living tomopterids and was probably pelagic. This discovery indicates that these polychaetes were well established by the early Carboniferous and probably before.     

The affinities of conodonts—new evidence from the Carboniferous of Edinburgh, Scotland

Three new specimens which preserve the soft parts of conodonts are described from the Lower Carboniferous of Granton, Edinburgh. The animal was apparently laterally flattened in life and the somites were V-shaped. The nature of the preserved axial lines is equivocal; some may represent the walls of the gut. The elements of one of the new specimens show that it does not belong to Clydagnathus , to which the other soft-bodied specimen from Granton was tentatively assigned. The possibility of a relationship between the euconodonts and the Chaetognatha is discounted. Nor do the conodonts constitute a phylum, but are a separate group of primitive jawless craniates.     

Radiizonates arcuatus, a distinctive new miospore species from the Lower Carboniferous of Western Gondwana

A new species of trilete zonate miospores, Radiizonates arcuatus, is established for Lower Carboniferous Western Gondwanan forms hitherto ascribed misguidedly to Radiizonates genuinus (Jushko) Loboziak and Alpern (1978), a Russian Lower Carboniferous species. The latter binomen is, moreover, not a valid combination and is more correctly designated as Vallatisporites genuinus (Jushko) Byvsheva, 1980. R. arcuatus is, from records to date, confined to westerly parts of Gondwana (Brazil, North Africa and Middle East), in which it is characteristic of Early Carboniferous strata, albeit with some slightly older and slightly younger occurrences.     

Chondrichthyans from the Lower Carboniferous of Yakutia,Russia

Paleontological Journal - Teeth of Cladodoides cf. wildungensis (Jaekel), fin spines of Ctenacanthus cf. angulatus Newberry et Worthen and Ctenacanthus sp. occur in the Lower Carboniferous Emyaksin...     

A Partially Permineralized Lepidophloios from the Early Upper Carboniferous of Scotland

A terminal shoot of Lepidophloios with both external morphologyand anatomy preserved is described. It is compared to the compressionspecies L. scoticus and the permineralized species L. scottiiand L. wuenschianus, all from the Lower Carboniferous of Scotland.It is characterized by the leaves having been abscissed rightup to the stem apex and by the occurrence of deflected and overlappingleaf cushions near the apex. These features are in contradictionwith current concepts about the growth of these plants. Lepidophloios, anatomy, arborescent lycopod, Carboniferous, leaf growth, terminal shoot     

High-resolution biostratigraphy of the Tournaisian-Visean (Carboniferous) boundary interval, Mokrá quarry, Czech Republic

This paper summarizes the results of investigations carried out in the Mokrá quarry since 2006 on the biostratigraphy of the Tournaisian-Visean (T-V) boundary interval. It also integrates previous results obtained by J. Kalvoda and collaborators. The main focus is on the boundary itself, but stratigraphically lower and higher levels have been investigated as well to provide a biostratigraphical context spanning the late Tournaisian to early Visean. This stratigraphical level has been the focus of intense international research in the recent years under the auspices of the Subcommission on Carboniferous Stratigraphy (SCCS) in order to find a new criterion and reference section (Global Stratotype Section and Point, GSSP) for the base of the Visean Stage. The appearance of Eoparastaffella simplex from its ancestor E. “ovalis” and the Pengchong section (Guangxi, southern China) have recently been proposed by the Task Group on the Tournaisian-Visean Boundary and ratified by the SCCS as the new biostratigraphic criterion and GSSP for the base of the Visean, respectively. The sequence exposed in Mokrá is not suitable as a GSSP, notably because it is an active quarry, but it contains most of the foraminifer and conodont guides allowing a high-resolution biostratigraphy of the boundary interval. In addition, it contains abundant trilobites. For these reasons, it constitutes one of the best sections across the T-V boundary in Europe and can serve as a useful additional reference.     

The First Stem Tetrapod from the Lower Carboniferous of Gondwana

The first stem tetrapod from Gondwana, Ossinodus pueri gen. et sp. nov, is described from fragmentary material that includes a skull table and many important parts from the postcranial skeleton. It was recovered together with a typically non-marine to marginal (near) marine fish fauna from the Lower Carboniferous (mid Viséan) Ducabrook Formation, Queensland, Australia. Phylogenetic analysis hypothesises that Ossinodus belonged to a clade that includes Whatcheeria and Pederpes , positioned on the stem of the crown tetrapods, one step crownward of Tulerpeton . Hind limb morphology suggests that small specimens of Ossinodus were primarily aquatic but that larger ones were less so.     

A bryozoan buildup from the Lower Carboniferous of North Wales

A carbonate buildup dominated by trepostome Bryozoa is described from Dinantian (Asbian) strata near Llandudno in North Wales. A three-phase ecological succession is recognised within the buildup: (i) a basal diverse community with fenestrate, ramose, encrusting trepostome and cystoporate bryozoans in a mud rich wackestone; (ii) a bulk facies, dominated by encrusting and foliaceous, trepostome bryozoans in a fine packstone, and (iii) a thin capping phase, dominated by unilaminar, encrusting trepostome bryozoans in a slightly coarser lithology, including skeletal debris derived from the mound top and possible flanking beds. The buildup probably had topographic relief and developed in a shallow marine environment. The internal tripartite zonation reflects the growth of the structure into a shallower, higher energy regime, with the capping beds being deposited just below wave base. The buildup developed to the north of St. George's Land, on a carbonate shelf edge bordering the deeper basinal facies of the Irish Sea Basin. Dinantian, Asbian, buildup, trepostome Bryozoa, Foraminifera, corals, calcareous algae, Carboniferous, North Wales .     

The corystosperm pollen organ Pteruchus from the Triassic of antarctica

The permineralized corystosperm pollen organ Pteruchus is described from the early Middle Triassic of Antarctica. Pteruchus fremouwensis consists of an axis bearing numerous, helically arranged microsporophylls, each of which terminates in a distal flattened head. The axis is 1–2 mm in diameter and eustelic. Spherical to elliptical secretory cavities are present in the ground tissue of the axis, microsporophyll, and pollen sac wall. The basal stalk of the microsporophyll is vascularized by a C-shaped strand that gives rise to a midvein and numerous lateral veins in the distal head. At least 38 pollen sacs are borne on the abaxial surface of the microsporophyll head. These are arranged in pairs on either side of lateral veins. Each pollen sac is sessile, elongated, and uniloculate. The pollen sac wall is several cell layers thick early in ontogeny, but reduced to a single layer in thickness when mature. Dehiscence is longitudinal along the inner surface. Pollen is monosulcate and bisaccate, and of the Alisporites-type. The Triassic specimens are the first structurally preserved pollen organs of the Pteruchus-type and can be related to the associated corystosperm stem and leaf genera based on the presence of unique secretory cavities. The morphology of Pteruchus and the relationship of this pollen organ with other Mesozoic and Paleozoic pollen organs is discussed.