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.     

New bryozoans from the Devonian of Gorny Altai (Russia)

New bryozoans Saffordotaxis altaicus sp. nov. from the Givetian Stage (Middle Devonian) and Cyphotrypa olgae sp. nov. and Crustopora aliena sp. nov. from the Famennian Stage (Upper Devonian) are described from the Devonian of Gorny Altai.     

RELLIMIA THOMSONII FROM THE GIVETIAN OF NEW YORK: SECONDARY GROWTH IN THREE ORDERS OF BRANCHING

Pyritized axes of the vegetative branching system of Rellimia thomsonii, from the Givetian of New York were described with emphasis on the presence and position of the secondary tissues in relation to the known axis orders. The morphology and anatomy of four axis orders (N, N + 1, N + 2, N + 3) was described using two well-preserved specimens. One specimen showed the largest known (N) axis order, with spirally attached N + 1 axes. The other specimen, from a more distal portion of the plant, showed the N + 2 axis order with spirally arranged N + 3 axes. The shape of the primary xylem, discernible in three of the axis orders (N + 1, N + 2, N + 3), was a three-lobed protostele with mesarch maturation of the primary xylem. The protostele of the N + 3 axis order, with only primary growth, was identical to that of fertile N + 3 axes. The other axis orders (N + 2, N + 1, N) had wood surrounding the primary xylem. The wood of the N+2 axis was limited, and occurred only in the basal portion of the axis, but that of the N+1 and N axes was extensively developed with two and three growth layers, respectively. This wood was pycnoxylic with narrow rays similar to other aneurophytalean progymnosperms. Surrounding the secondary xylem was secondary phloem indicating the vascular cambium in Rellimia was bifacial. The presence of growth layers was discussed in relation to the climatic interpretation placed on their presence and how it correlates with paleogeographic reconstructions of the Devonian.     

PROTEOKALON A NEW GENUS OF PROGYMNOSPERMS FROM THE DEVONIAN OF NEW YORK STATE AND ITS BEARING ON PHYLOGENETIC TRENDS IN THE GROUP

Proteokalon gen. nov. is described from the Upper Devonian Catskill deposits of New York. Two orders of branching and ultimate appendages are preserved' by petrifaction and by compression. The first order bears branches decussately and has a skewed four-armed protostele that occasionally dichotomizes. Second-order branches dichotomize rarely and most have T-shaped or three-armed protosteles. They bear ultimate appendages alternately, either in lateral pairs, or singly from the abaxial side. These appendages divide several times in one plane. Their vascular strand is terete. Maturation of the primary xylem is mesarch, and it consists of tracheids and parenchyma. Secondary xylem and phloem and a periderm are present. The outer cortex has a system of hypodermal fibers. Proteokalon is most similar to Tetraxylopteris and Triloboxylon of the Aneurophytales. A comparison of the stratigraphic occurrence of Protopteridium, Aneurophyton, Tetraxylopterism, Sphenoxylon, Triloboxylon, and Proteokalon suggests some evolutionary trends among the Aneurophytales.     

Devonian Gastropoda from the Dornap “Massenkalk” complex (Bergisches Land,Germany)

Seven Middle Devonian (latest Givetian or earliest Frasnian) gastropod species are described from the quarry of Oetelshofen near Dornap (Bergisches Land, northwestern Rheinisches Schiefergebirge, Germany). New species areMurchisonia dornapica, Araeonema osterholzensis, Plagiothyra isekei andMacrochilina drozdzewski. Additionally, a new subspecies,Euryzone delphinuloides oetelshofensis and aNaticopsis-like species and their typical facial occurrence are discussed. The existence of predation is proved by a bore-hole inMacrochilina drozdzewski; the predator itself is not yet identified with certainty.      

Middle Devonian dendroid graptolites from the Brilon Reef area (Rheinisches Schiefergebirge, Germany)

Dendroid graptolites from the Middle Devonian (Givetian, middlePolygnathus varcus Biozone) of the Rheinisches Schiefergebirge are described for the first time. The fauna of the Burgberg locality south of the Brilon reef comes from a black shale layer in a succession of calcareous debris flows. The fauna includes five species ofDictyonema andRuedemannograptus described in open nomenclature. The fragmentation of the material is conside-red as an indication of post-mortem transport.      

Ecology and evolution of Devonian trees in New York,USA

The first trees in New York were Middle Devonian (earliest Givetian) cladoxyls (?Duisbergia and Wattieza), with shallow-rooted manoxylic trunks. Cladoxyl trees in New York thus postdate their latest Emsian evolution in Spitzbergen. Progymnosperm trees (?Svalbardia and Callixylon–Archaeopteris) appeared in New York later (mid-Givetian) than progymnosperm trees from Spitzbergen (early Givetian). Associated paleosols are evidence that Wattieza formed intertidal to estuarine mangal and Callixylon formed dry riparian woodland. Also from paleosols comes evidence that Wattieza and Callixylon required about 350 mm more mean annual precipitation than plants of equivalent stature today, that Wattieza tolerated mean annual temperature 7 °C less than current limits of mangal (20 °C), and Callixylon could tolerate temperatures 14 °C less than modern mangal. Devonian mangal and riparian woodland spread into New York from wetter regions elsewhere during transient paleoclimatic spikes of very high CO₂ (3923 ± 238 ppmv), and subhumid (mean annual precipitation 730 ± 147 mm) conditions, which were more likely extrinsic atmospheric perturbations rather than consequences of tree evolution. For most of the Middle Devonian CO₂ was lower (2263 ± 238 ppmv), and paleoclimate in New York was semiarid (mean annual precipitation 484 ± 147 mm). Such transient perturbations and immigration events may explain the 40 million year gap between the late Emsian (400 Ma) evolution of trees and Famennian (360 Ma) CO₂ drawdown and expansion of ice caps.     

Two new Middle Devonian megaspores from Saudi Arabia

Two new megaspore species, Biharisporites jubahensis and Verrucisporites yabrinensis, are described from the Middle Devonian Jubah Formation of south central Saudi Arabia. Miospore-based biostratigraphy indicates that the age of the megaspore-bearing interval is no older than the early Givetian Geminospora lemurata Interval Zone, and not younger than Givetian. The presence of similar species in both Arctic Canada and Saudi Arabia suggests that the megaspore-producing plants achieved wide distribution in the Middle Devonian.     

Earth's oldest liverworts—Metzgeriothallus sharonae sp. nov. from the Middle Devonian (Givetian) of eastern New York,USA

Liverworts are generally regarded as rare elements in Palaeozoic floral assemblages. However, a focus on dark gray to black shales and siltstones in the Middle–Late Devonian Catskill Delta of eastern New York shows that liverworts are locally quite common as well-preserved, apparently parautochthonous specimens in thin, lenticular, dark gray–black shale and siltstone lenses. These lenses are either dysoxic–anoxic lacustrine or estuarine facies deposited under oxygen-stratified water masses or rapidly deposited flood plain deposits that were not oxidized after deposition. Carbonized remains of the upper Middle Devonian (Givetian) liverwort Metzgeriothallus sharonae sp. nov. are locally common in these lenses. Well-preserved thalli (gametophytes) are only evident by projecting polarized light on the shale and siltstone surfaces. An associated sporophyte capsule is the first evidence of a reproductive structure in a Devonian liverwort. Metzgeriothallus sharonae sp. nov. is the oldest known liverwort. The age of the new species helps recalibrate chloroplast DNA studies that have led to proposals of the timing of liverwort diversification by showing that the evolutionary separations of the Jungermanniopsida and Marchantiopsida and of the Metzgeriidae and Jungermanniidae [previously thought to be Late Devonian and Late Carboniferous, respectively] were no younger than late Middle Devonian.     

A new species of psammosteiform heterostracan (Agnatha) from the Givetian (Middle Devonian) of the Voronezh Region

A new pycnosteid species, Schizosteus shkurlatensis sp. nov. (Agnatha, Psammosteiformes), from the Staryi Oskol beds (Givetian, Middle Devonian) of the Voronezh Region is described. This is the first species of the genus Schizosteus Obruchev from the Central Devonian Field. The similarity between species of this genus and early species of Psammolepis is discussed.     

A POST‐SCRIPT TO THE ENIGMATIC PROTONYMPHA (DEVONIAN; NEW YORK): IS IT AN ARM OF THE ECHINODERMS?

Abstract:  A unique specimen of the supposed arm of the Middle Devonian (Givetian) starfish Foliaster transversus Blake, 1994[ Journal of Palaeontology , 68, 123–134] is shown to be closely comparable to the enigmatic organism Protonympha salicifolia , also of Devonian age, albeit slightly younger (Frasnian), and also from New York State. Similarities to starfish, or any other echinoderm, appear to be superficial. Differences from the type species of Protonympha are minor, but include the detailed structure of the transverse segments. For this reason a specific distinction is retained, and the taxon Protonympha transversa (Blake, 1994) now proposed. Enigmatic fossils such as Protonympha raised related questions of evolutionary affinity and the problems of pattern recognition. These questions may also touch on the interpretation of organic structures, such as might be returned from Mars (or further afield).     

THE CUTICLE OF DREPANOPHYCUS SPINAEFORMIS,A LONG-RANGING DEVONIAN LYCOPOD FROM NEW YORK AND EASTERN CANADA

The presence of paracytic stomata and paired guard cells on specimens presumed to be Drepanophycus spinaeformis Göppert from eastern Canada and New York State supports the conclusion of Banks and Grierson that the species is not a reliable index of Lower Devonian strata. The interpretation of stomatal morphology demonstrates that the species lived in Early, Middle, and Late Devonian time and that slender specimens are distinct from zosterophylls such as Sawdonia that had anomocytic stomata and a single guard cell. Knowledge of the stomata also permits a reinterpretation of the stomatal apparatus as first described by Lang. Siegenian specimens of the genus apparently represent the oldest occurrence of paired guard cells and of paracytic stomata.     

Middle Devonian bothriolepiform antiarchs (Pisces,Placodermi) from central Kazakhstan and their implication for the antiarch system and phylogeny

The bothriolepiform antiarchs Tenizolepis asiatica (Obrucheva, 1955), Bothriolepis kassini Malinovskaja, 1988, and B. babichevi Malinovskaya, 1992 from the Givetian (Middle Devonian) of Central Kazakhstan are redescribed. Tenizolepis bychkovi Malinovskaya, 1992, known from the Konyr Formation of the Trudovoe vertebrate locality, is considered to be a synonym of B. babichevi. The history of investigation of bothriolepiforms from Kazakhstan is discussed. The system and phylogeny of antiarchs are discussed.     

The Givetian flora from Cairo, New York: Rhacophyton, Triloboxylon and Cladoxylon

Petrified Rhacophyton, Triloboxylon and Cladoxylon are described from the Givetian of eastern New York State. In cross section, specimens referable to Rhacophyton ceratangium have a mesarch primary xylem strand in the shape of a bar with swollen endS. Pycnoxylic secondary xylem surrounds the primary xylem. Vascular strands, interpreted as traces, are also present. Triloboxylon has a three-fluted primary xylem strand surrounded by secondary xylem. Several mesarch protoxylem areas are present in cross sectional view. The specimens of Cladoxylon , the first of this genus in the Middle Devonian of North America, show the typical polystelic pattern in cross section. Obvious secondary xylem and peripheral loops are absent. Lateral appendages were observed on two of the specimenS. A comparison of the Cairo and Gilboa floras indicates that they represent different ecological niches during the late Middle Devonian.     

Trilobites Asteropyginae dévoniens d’Iran

Ten species of trilobites belonging to 4 genera of the sub-family Asteropyginae DELO are described from the Devonian (Givetian-Frasnian) of Iran. Three of which are new: Neocalmonia lutensis nov. sp., Neocalmonia yazdii nov. sp. and Radiopyge sardarensis nov. sp. The study of this material have required the revision of Heliopyge sharudensis(PILLET, 1974) from the Givetian of the Eastern Alborz Mountains and of Neocalmonia quadricosta PILLET, 1969, type-species of the genus Neocalmonia, from the Frasnian of Afghanistan. The recognition of genera and species in common with the Givetian and the Frasnian of Afghanistan emphasizes the close relations between these two regions. The genera Bradocryphaeus, Heliopyge, Neocalmonia, Radiopyge, represented by related species, are likewise present in Iran, Afghanistan and Western Europe. Their presence confirms that these regions belong, during the Devonian, to the North Gondwanian domain.     

Two species of Haskinsia Grierson & Banks (Lycopsida) from the Middle Devonian of Xinjiang,China, and consideration of their palaeogeographical significance

Two species of the Devonian herbaceous lycopsid Haskinsia Grierson & Banks, H. hastata Berry & Edwards and H. sagittata Edwards & Benedetto, are reported from the Hujiersite Formation (Givetian–Middle Devonian), Xinjiang, north‐west China. Both species were first described from Venezuela. Haskinsia hastata from Xinjiang has hastate leaves with toothed margins, and a pair of basal narrow lateral segments which curve distally. It is assigned to a new subspecies because of the toothed margins which cannot be demonstrated in Venezuelan material. The scar of the sporangium stalk is observed for the first time in specimens of H. sagittata, on the leaves of which a possible ligule structure is also shown. On the basis of our observations on both Xinjiang and Venezuelan specimens, the diagnosis of Haskinsia is enlarged to accommodate plants whose lamina has entire or toothed margins. The palaeophytogeography of the genus, otherwise known from South and North America, is discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 633–644.     

Thinopus and a Critical Review of Devonian Tetrapod Footprints

Devonian tetrapod tracks and trackways can be recognized by three criteria: morphology of the manus and pes impressions that matches known Devonian tetrapod skeletal morphology, manus smaller than pes, and the alternating trackway pattern that results from lateral sequence walking in quadrupedal tetrapod locomotion. The first reported Devonian tetrapod track, named Thinopus antiquus, from Pennsylvania, is not a tetrapod track and is likely an impression of a fish coprolite(s). A critical review of the published Devonian track record indicates only three can be verified as produced by a tetrapod trackmaker—Genoa River, Australia; Easter Ross, Scotland; and Valentia Island, Ireland. The supposed tetrapod tracks from the Middle Devonian of the Zache?mie quarry, Poland, fail the criteria for identification as Devonian tetrapod tracks. Indeed, no convincing case has been made that the Zache?mie structures are tetrapod tracks. Instead, they are reinterpreted as fish nests/feeding traces (ichnogenus Piscichnus). The oldest Devonian tetrapod trackway is Givetian and this is the oldest record of a tetrapod, but the sparse record of Devonian tetrapod tracks is of no other biostratigraphic and little paleobiogeographic significance. Bona fide Devonian tetrapod tracks are from nonmarine facies, so they do not support a marginal marine origin of tetrapods. They indicate lateral sequence walking and pelvic-limb-propelled, fully terrestrial (subaerial) locomotion in freshwater environments by at least some Devonian tetrapods.     

Revision of the disparid Stylocrinus (Crinoidea) from the Devonian of Europe,Asia and Australia

Abstract: The discovery of new specimens and the restudy of known collections result in revision of the diagnosis and the stratigraphic distribution of the disparid crinoid genus Stylocrinus, from the Middle and Upper Devonian of Europe, Asia and Australia. The consistent development of three basal plates, the atomous arms with internally inclined edges adjoining laterally with adjacent brachials in an interlocking network and an apparently rudimentary pinnulation is recognised. The high ecophenotypic plasticity of the common species S. tabulatus negates the validity of several former subspecies and demonstrates the general morphologic variability of the aboral cup proportions. This contrasts with the low morphological spectrum of rarer stylocrinid species. With exclusion of ‘S. elimatus’ (Silurian) from Stylocrinus, the genus is limited to the Devonian. A neotype is proposed for the lost holotype of S. tabulatus. Stylocrinus prescheri sp. nov. is described from the Eifelian to Givetian of Europe and Asia. The first evidence of the gastropod grazing trace fossil Radulichnus on a crinoid aboral cup (S. tabulatus), the post‐mortem incurred ossicular‐boring of radial and basal plates as well as the post‐mortem encrusting by a rugose coral are further observations on Stylocrinus aboral cups.     

<Emphasis Type="Italic">Istchenkophyton filiciforme</Emphasis> gen. et sp. nov., a new small vascular plant with thick cuticle from the Devonian of Voronezh Region (European Russia)

Remains of a new small vascular plant, Istchenkophyton filiciforme gen. et sp. nov., are described from the Upper Givetian strata of Pavlovsk vicinity (Voronezh Region). The plant is characterized by a very thick cuticle (up to 300 μm), complex branching pattern, similar to that of a frond rachis, anomocytic stomata, and a well-developed vascular bundle with a central elongated in transversal section protoxylem strand and massive metaxylem composed chiefly of scalariform bordered-pitted tracheids. A reconstruction of the new plant is proposed; its ecology and systematic position are considered. In the light of new data relationships of problematic Devonian plants with thick cuticle are discussed.     

Mid Devonian megaspores from Yunnan and North Xinjiang,China: Their palaeogeographical and palaeoenvironmental significances

The megaspore Verrucisporites lui nom. nov. is described from the Middle Devonian (Givetian) of both Yunnan (Xichong Formation) and Xinjiang (Hujiersite Formation), China. Coeval megaspores of Longhuashanispora from Yunnan are also SEM illustrated for comparison. Petrological examination of coal from the Hujiersite Formation shows it to be vitrinite and representative of an early peat forming wetland environment. Verrucisporites is known from both Laurasia and East Gondwana. Its discovery in the volcanic arcs of the Altaids shows that a migration path was present for plants between South China and Laurasia.