Serrulacaulis furcatus gen. sp. nov., a New zosterophyll from the lower upper devonian of New York state

A new zosterophyll is described from the lower Upper Devonian of New York. Serrulacaulis furcatus is characterized by two rows of emergences which are opposite in arrangement and attached on opposite margins of the axis. They are deltoid in side view and are contiguous vertically, giving the stem a scalloped or saw-toothed appearance. Epidermis over much of the plant consists of elongate cells and interspersed isodiametric cells. The vascular strand consists of spirally thickened tracheids. Rhizomes are densely covered by rhizoids that are more numerous on small papillae and at the apex of tooth-like emergences. Aerial axes terminate in circinate apices. Some axes bear short-stalked, reniform sporangia arranged alternately in two rows on one side of the axis only. The dehiscence zone is a thickened rim over the distal, convex margin of the sporangium. Dehiscence is basipetal, producing two equal valves. Spores are smooth to slightly granulate, circular to subtriangular, with a trilete mark that extends $\text{1}\text{3}$–$\text{1}\text{2}$ the radius and is surrounded by a darkened triangular area. Sawdonia ornata, described earlier from the same quarry, and now Serrulacaulis, are the two genera of zosterophylls proven to occur in Late Devonian time. The world-wide distribution of zosterophylls and the fact that the group is a natural one are reviewed.     

A new genus of Early Devonian plants with novel strobilar structures and vegetative appendages from the Posongchong Formation of Yunnan,China

A new plant, Dibracophyton acrovatum gen. et sp. nov., is described from the Lower Devonian (Pragian) Posongchong Formation of Wenshan District, southeastern Yunnan, China. The plant has creeping axes from which arise vegetative and fertile axes. The vegetative axes helically bear lateral dichotomous appendages with curved or round tips. The fertile axes possess terminal strobili with numerous fertile units arranged in irregular helices. Each fertile unit consists of a stalked long-elliptical sporangium, with dehiscence into two equal valves, and two discrete long-ovate bracts covering sporangium from above–below directions. A new genus and species is thus established based on these characters and is temporarily regarded as incertae sedis of Tracheophyta, although it perhaps closes to the barinophytes in affinity. Detailed comparisons with other plants having a similar architecture, i.e., sporangia closely associated with modified vegetative structures, are made. The discovery of D. acrovatum further enriches the composition of the Posongchong flora and demonstrates great morphological disparity of the Early Devonian vascular plants.     

A Lower Devonian hexacrinitid crinoid (Camerata,Monobathrida) from south-west England

The most species-rich and widespread crinoid clade in the type area of the Devonian of south-west England is the monobathrid camerate family Hexacrinitidae Wachsmuth and Springer. These crinoids occur either as thecae (Middle Devonian) or pluricolumnals and columnals (Lower to Upper Devonian). The first new, nominal species of hexacrinitid, probably Oehlerticrinus Le Menn, to be described from this region since the nineteenth century is Oehlerticrinus peachi sp. nov. from the Lower Devonian Looe Basin of southern Cornwall. This specimen is mouldic and somewhat flattened, retaining the proxistele and arms. Diagnostic features include the heteromorphic proxistele with circlets of long, unbranched radices directed towards the crown; the high, box-like (=skyphosiform) theca with a flattened base; a thecal plate sculpture of tubercles and ridges arranged in triangles; and the pinnulate arms. Any uncertainty in identifying this species at the generic level rests with the arms being pinnulate, not ramulose as is common in Hexacrinites Austin and Austin, indicating that O. peachi is closer to Oehlerticrinus Le Menn.     

A new plant with novel leaves from the Upper Devonian of Zhejiang Province,China

The evolution of vascular plants during the Devonian Period has had great impacts on terrestrial ecosystems through innovations of key characters such as leaves, heterospory, seed reproduction, and woods. Here we report a new plant, Qianshouia mira n. gen. n. sp., from the Upper Devonian Wutong (Wutung) Formation of Fanwan section, Changxing County, Zhejiang Province, China. This plant has slender axes which seldom branch. Its leaves are arranged in pseudowhorls, departing from axes with an acute angle. The leaves are strap-shaped and each can be subdivided into proximal, middle and distal portions. At the proximal portion, a middle ridge develops, and at the middle portion this ridge divides at least three times forming four to six daughter ridges, and in between are grooves. The distal portion of leaves (leaf apex) is suggested to be adaxially curved, with no ridges but with forked tips. Qianshouia probably represents a small plant with a shrubby or herbaceous habit. Due to the unique leaf morphology and the lack of fertile structures and anatomy, the exact phylogenetic position of Qianshouia is uncertain. Qianshouia might be a lycopsid in light of the pseudowhorled phyllotaxis, or alternatively, could be a sphenopsid if the dichotomous ridge system of the leaf could be demonstrated to be leaf veins. Nevertheless, Qianshouia adds to the diversity of leaf morphologies among the Late Devonian vascular plants.     

Vegetative Characters,Growth Habit and Microsporangiate Strobilus of Lycopsid Minostrobus chaohuensis

Late Devonian Minostrobus chaohuensis is one of the earliest monosporangiate-strobilate isoetaleans. Based on new material of this plant, the vegetative axis and microsporangiate strobilus are studied in detail, and the whole plant knowledge is summarized. The vegetative axis is isotomously branched. The stem is up to 55 mm in diameter with helically arranged leaf cushions. Stems and thick branches bear long fusiform leaf cushions and interareas with vertical linear ornamentations. A ligule pit, oblanceolate leaf scar, and vascular bundle scar appear on the leaf cushion. Distal axes have persistent lanceolate leaves and rhombic leaf bases. The microsporangiate strobilus is cylindrical in shape, possesses sporophyll with alate pedicel and long triangular lamina, uniseriate sporangial wall, subarchesporial pad inside the sporangium, and microspore with cingulum. Based on comparisons with other isoetaleans, the usage of the terms “leaf cushion” and “leaf base” is discussed, and Minostrobus chaohuensis is considered as a tree-like lycopsid. It suggests that arborescent isoetaleans with monosporangiate strobili had appeared and diversified in the Late Devonian. The multi-dichotomous branching system of Minostrobus provides new data on the evolution of growth architecture in rhizomorphic lycopsids.     

Schischcatella (Fenestrata,Bryozoa) from the Devonian of the Rhenish Massif,Germany

Abstract: The Devonian fenestrate bryozoan, Schischcatella Waschurova, 1964 , possessed colonies in the form of low, erect bifoliate fronds that grew from an encrusting sheet‐like base with autozooecia arranged in biserial, bifurcating rows. This growth habit is unique in fenestrates, which normally had unilaminate arborescent colonies. Originally, Schischcatella was described from the Lower Devonian of Tajikistan. This article describes a new species, S. heinorum sp. nov., from the Middle Devonian of the Eifel (western Rhenish Massif, Germany) with additional material from the Lower Devonian of the Kellerwald (eastern Rhenish Massif, Germany). External and internal morphologies of this bryozoan have been studied using abundant material. The growth habit of Schischcatella suggests a completely different pattern of feeding currents than that in the normal fenestrate colony. The outflow of the filtered water occurred only on edges of colonies between rami. In the absence of chimneys (areas of vertical water expelling), such a functional morphology may have restricted extension of the colony in a distal direction. The evolution of Schischcatella is apparently an example of paedomorphosis, the genus evolved from an unknown semicosciniid species by the early ontogenetic interruption of colony development and further changes in the mode of growth.     

Spores and the middle-upper Devonian boundary

The stratigraphic levels most favoured for the Middle-Upper Devonian boundary fall approximately within the range of the ammonoid Pharciceras lunulicosta Zone, i.e. from the Middle varcus Subzone to the base of the Lower asymmetricus Zone of the conodont scale. Spore data that are potentially useful for recognition of the boundary within this range have been correlated with conodont zones in marine facies in the Boulonnais region of France. A vast amount of information on spores from Middle-Upper Devonian boundary strata has accumulated in the European U.S.S.R., where the boundary is taken at a somewhat lower level. Late Givetian and early Frasnian continental strata of Melville Island in the Canadian Arctic contain species present in the Boulonnais or the European U.S.S.R., as well as species common to both regions. Diatomozonotriletes spp., Rhabdosporites langii, Samarisporites triangulatus, Contagisporites optivus, Archaeoperisaccus timanicus, Chelinospora concinna and Ancyrospora langii, among others, may be useful for correlating the boundary as eventually defined. The stratigraphic ranges of most of these taxa show only limited agreement interregionally at present, probably owing at least in part to problems of spore nomenclature and taxonomy, and an insufficiency of spore reference sequences keyed to faunal zones. Nevertheless, individual species of spores, and especially assemblages of species, have much potential for delimiting and correlating the Middle-Upper Devonian boundary in both marine and continental facies.     

Leaf evolution in early-diverging ferns: insights from a new fern-like plant from the Late Devonian of China

Background and Aims With the exception of angiosperms, the main euphyllophyte lineages (i.e. ferns sensu lato, progymnosperms and gymnosperms) had evolved laminate leaves by the Late Devonian. The evolution of laminate leaves, however, remains unclear for early-diverging ferns, largely represented by fern-like plants. This study presents a novel fern-like taxon with pinnules, which provides new insights into the early evolution of laminate leaves in early-diverging ferns.Methods Macrofossil specimens were collected from the Upper Devonian (Famennian) Wutong Formation of Anhui and Jiangsu Provinces, South China. A standard degagement technique was employed to uncover compressed plant portions within the rock matrix.Key Results A new fern-like taxon, Shougangia bella gen. et sp. nov., is described and represents an early-diverging fern with highly derived features. It has a partially creeping stem with adventitious roots only on one side, upright primary and secondary branches arranged in helices, tertiary branches borne alternately or (sub)oppositely, laminate and usually lobed leaves with divergent veins, and complex fertile organs terminating tertiary branches and possessing multiple divisions and numerous terminal sporangia.Conclusions Shougangia bella provides unequivocal fossil evidence for laminate leaves in early-diverging ferns. It suggests that fern-like plants, along with other euphyllophyte lineages, had independently evolved megaphylls by the Late Devonian, possibly in response to a significant decline in atmospheric CO₂ concentration. Among fern-like plants, planate ultimate appendages are homologous with laminate pinnules, and in the evolution of megaphylls, fertile organs tend to become complex.     

A new early Frasnian (Late Devonian) foraminifer from eastern Taurides (Turkey): Evolutionary and paleobiogeographic implications

A complete Devonian sequence is well exposed in the eastern Taurides, forming more than 1000 m-thick succession of carbonate and siliciclastic sediments. The carbonate succession, stratigraphically ranging from Middle Devonian to early Late Devonian and mostly comprising limestones, dolomitic limestones and reefal limestones, contains abundant and diverse assemblages of foraminifers, corals, stromatoporoids, calcareous algae, bivalves, brachiopods, ostracods, and conodonts. The limestone samples collected from a more closely sampled stratigraphic section have been investigated for their foraminiferal content. The micropalaeontological analyses carried out on these samples have revealed the presence of an early Frasnian foraminiferal assemblage including predominantly unilocular parathuramminid species and multilocular forms of the genera Nanicella, Paratikhinella and Semitextularia? and further indicated the presence of a new genus and a new species Halevikia deveciae n. gen. n. sp. which appears as an important phylogenetic and stratigraphic transitional taxon between the families Baituganellidae n. fam. and Tournayellinidae, the phylogenetic potentiality of which during the Late Devonian is currently probably underestimated.     

SVALBARDIA BANKSII SP. NOV. FROM THE UPPER DEVONIAN (FRASNIAN) OF NEW YORK STATE

Svalbardia banksii sp. nov., is described from the Upper Devonian (Frasnian) Fish Cabin Creek locality near Pond Eddy, New York. The compression consists of ultimate branches bearing spirally arranged, unwebbed leaves. The unwebbed leaves are up to 3.2 cm long, are somewhat flexuous, and dichotomize in more than one plane. The new species is similar to the reconstruction of Actinoxylon banksii from the Middle Devonian (Givetian) of New York and strengthens the supposed relationship between Svalbardia polymorpha and Actinopodium nathorstii from Mimerdalen, Spitzbergen.     

Re-study of Minostrobus chaohuensis Wang (Lycopsida) from the Upper Devonian of Anhui,South China

Minostrobus chaohuensis Wang was previously known only as a lycopsid megasporangiate strobilus from the Upper Devonian of Anhui Province, South China. Our comprehensive study of the newly collected materials reveals the details of its morphology, anatomy, and reproduction, which allow us to emend its generic and specific diagnoses. M. chaohuensis is reconstructed as a plant with multi-dichotomous branching system, helically arranged leaves, and monoecious and monosporangiate strobili (i.e., separate megasporangiate and microsporangiate strobili in one individual). The anatomy of both fertile and sterile portions of Minostrobus indicates that the exarch primary xylem strand is the solid protostele, with the peripheral protoxylem ridges and Williamson's striations in metaxylem tracheids. The key reproductive and anatomical characters suggest that Minostrobus chaohuensis is far more likely to represent a distal shoot of pseudo-herbaceous or arborescent lycopsids within the order Isoëtales sensu lato. It is suggested that the monosporangiate-strobilus clade in the Isoëtales may include primitive, monoecious taxa in the Late Devonian and advanced, dioecious ones in the Carboniferous. The hypothesis that the more phylogenetically advanced monosporangiate-strobilus clade might have well diverged from the basal bisporangiate-strobilus clade of arborescent lycopsids by the Late Devonian is further supported.     

Devonian floral assemblages and plant megafossils from the Iberian Peninsula: A review

This paper presents a review and critical analysis of the literature on Devonian floras of the Iberian Peninsula. Although the known outcrops of Devonian strata in the Iberian Peninsula are marine, in some cases, a few fragmentary remains of vascular plants are associated with faunal remains. Records include largely specimens from the Lower Devonian of Barrancos (Alentejo, Portugal) and the Upper Devonian of Sierra de Hornachos in Badajoz province, southwest Spain; the remainder consists of drifted plant fragments from scattered sites in the Iberian Peninsula ranging in age from Lochkovian to Upper Devonian-Earliest Carboniferous. The vegetation inferred for the Lower Devonian of the Iberian Peninsula is mainly based on palynological data and corresponds to herbaceous types characterised by bryophytes, rhyniophytes (Horneophyton, Cooksonia, Rhynia), trimerophytes (Psilophyton, Pertica and Hostinella), primitive lycophytes (Drepanophycus) and incertae sedis such as Nothia and Chaleuria, all flora that developed near the coast in low-lying and, at least periodically, wet areas. In the Middle Devonian, two vegetation strata can be recognised: herbaceous (Psilophyton) and semi-arboreal (Cladoxylales). Although three levels of vegetation in the Upper Devonian, have been described from outcrops worldwide, the scarce available data from the Iberian Peninsula only indicate an arborescent lycopsid vegetation and species with uncertain botanical affinity such as Sphenopteridium keilhauii Nathorst.     

Silurian-Devonian miospores from the western and central Algeria

The age of Rock Units B1 and B2 of the Middle Silurian-Lower Devonian of Sahara (Algeria) is assessed and confirmed as late Homerian to ?earliest Lochkovian on the basis of moderately well preserved miospore assemblages. The data upon which this age assessment is provided by recent palynological studies in the Cantabrian Mountains (NW Spain), the type Wenlock area, Shropshire (England), south and south-west Wales, the Midland Valley of Scotland and the Ghadames Basin, Libya. Quantitative study shows that cryptospores decrease in number and variety upwards, laevigate miospores are prevalent and the representatives of the rugulate, crassitate genus Scylaspora are dominant. The occurrence and range of these species as well as other miospore taxa recorded during this study provide the basis for recognizing three miospore assemblage and one interval biozones, namely Scylaspora vetusta-Scylaspora kozlica, Chelinospora sanpetrensis-Cymbosporites triangulatus, Chelinospora hemiesferica and Scylaspopra radiata-Apiculiretusispora synoria. Of these biozones, two assemblage biozones are proposed as new. Core samples of Rock Unit B1 from borehole NGS-1 of the Triassic Province contain the oldest two miospore assemblage biozones. Rock Unit B2 from the boreholes GMD-2, ISS-1 (Tidikelt Plateau) and NGS-1 (Triassic Province) comprise the youngest two miospore biozones. The assemblage and interval biozones allow inter-regional correlation with latest Middle Silurian to probably earliest Devonian strata. The inadequacy of coverage of core samples result in the absence of critical palynological evidence, to determine the exact position of the base of the Ludlow, Pridoli and Lochkovian. Comparison with the zonal and sub-zonal divisions of Mid-Palaeozoic sequences from other parts of the world shows crucial differences in the distribution of the spore flora within Gondwanan and Euramerican regions during Pridoli and early Lochkovian. Six new miospore species namely Retusotriletes delicatus nov. sp., Scylaspora cymba nov. sp., S. distincta nov. sp., S. radiata nov. sp., S. undulata nov. sp. and Cymbosporites triangulatus nov. sp. are described. Three more possibly new miospore forms are described and illustrated but not specifically named.     

Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond

Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and bilateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules.     

Morphology and wall ultrastructure of some Middle Devonian dispersed megaspores from northern Poland

Specimens of dispersed Middle Devonian megaspores have been isolated from core samples from the Miastko 1 borehole in Western Pomerania. Comprehensive investigations using light, scanning and transmission electron microscopy supplement previous information on morphology and gross structure and provide data on spore wall ultrastructure of four megaspore species. Corystisporites acutispinosus is azonate; the inner layer is laminate, and the lumen is lined by a thick, laterally continuous lamina. The outer layer consists of small, tangentially aligned tabular elements that become wider, more extensive and irregularly arranged toward the outside. Coronispora variabilis is a coronate megaspore; the inner layer appears homogenous and is probably lamellate. The outer layer consists of elongate, cylindrical, branching elements that are overlaid within the proximal part of the body by a lamellate, compact, almost homogenous layer. Grandispora ciliata is pseudosaccate. The inner body is laminate with laminae thickening and becoming less continuous and less tightly packed toward the outside. The outermost region of the inner body and the innermost region of the outer envelope consist of tabular and cylindrical elongate units. The bulk of the outer wall is almost homogenous, and near the surface it is granular. Pomeranisporites subtriangularis is pseudozonate. The inner layer appears homogenous except for the presence of a single innermost lamina. The inner part of the outer layer may represent small tabular and cylindrical elements, and the outer part comprises folded laminae. The megaspores studied share numerous features of morphology and wall ultrastructure with the lycopsids, putative lycopsids, and some enigmatic Devonian plants.     

Six new species of Agrilus Curtis, 1825 (Coleoptera,Buprestidae, Agrilinae) from the Oriental Region related to the emerald ash borer, A. planipennis Fairmaire, 1888 and synonymy of Sarawakita Obenberger, 1924

Six new species of Agrilus Curtis, 1825 with affinities to the emerald ash borer, Agrilus planipennis Fairmaire, 1888, are described from the Oriental Region: Agrilus crepuscularis sp. n. (Malaysia); Agrilus pseudolubopetri sp. n. (Laos); Agrilus sapphirinus sp. n.(Laos); Agrilus seramensis sp. n.(Indonesia); Agrilus spineus sp. n. (Malaysia); and Agrilus tomentipennis sp. n. (Laos). The genus Sarawakita Obenberger, 1924 syn. nov. is considered a junior synonym of Agrilus.     

Palaeoisopus,Palaeopantopus andPalaeothea,pycnogonid arthropods from the Lower Devonian Hunsriick Slate,West Germany

Palaeoisopus problematicus andPalaeopantopus maucheri are redescribed and found to be primitive pycnogonids belonging to extinct orders.Palaeoisopus is particularly primitive in retaining a long abdomen with a telson. It differs from other forms also in having flattened limbs indicating a swimming mode of life and in having the ocelli differently arranged.Palaeothea devonica nov. gen. et nov. spec. is a tiny pycnogonid, the only hitherto known fossil representative of the extant order Pantopoda, indicating that entirely modern forms were in existence already in the Early Devonian. A derivation of pycnogonids from early merostomes is regarded as likely.     

STRUCTURALLY PRESERVED PLANTS FROM SOUTHEASTERN KENTUCKY: STAUROPTERIS BISERIATA SP. NOV.

Several axes of the coenopterid fern Stauropteris are described from permineralized peat associated with Lower-Middle Pennsylvanian coal deposits of southeastern Kentucky. This represents the first documented report of the genus in North America. The specimens are regarded as representatives of a new species—S. biseriata—based on the distinctive branching habit. Three branch orders are described, and in each case, branches are singular and distichous, arranged in a two-ranked pattern. This is in contrast to other species of Stauropteris in which the branches are paired and form a quadriseriate pattern. A pair of vascularized aphlebiae subtend each branch through all branching orders. Aphlebiae associated with first- and second-order branches are three-parted at the point of insertion; those that subtend third-order branches are singular. Stauropteris and a number of Devonian fern-like plants are compared on the basis of certain morphological similarities.