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 Sphenophyllum plant from the Upper Devonian of Zhejiang Province,China

Sphenophyllum was an important and long-surviving sphenopsid genus in the Paleozoic floras, with a worldwide distribution. A new species, Sphenophyllum changxingense sp. nov., is described from the Upper Devonian Wutong Formation of Changxing County, Zhejiang Province, China. This plant is characterized by two orders of slender axes and wedge-shaped leaves borne in whorls. The axes bear short spines and show longitudinal ridges and furrows on surface. Three to eight isophyllous leaves, with one, two, or no second-order axes, are attached at each node of first-order axes. Leaves bear spines and show a bilobate morphology; the two leaf lobes divide distally to form several marginal segments, each segment with a leaf vein. Sphenophyllum changxingense represents an early and primitive species within the genus, in light of the absence of heterophylly and specialized hook-like leaves. Like some Carboniferous and Permian species, it appears to have formed dense mats with mutually supportive axes. This plant adds to the known diversity of early sphenopsids in the Late Devonian.     

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.     

A neotype for Colpodexylon gracilentum Dou (Lycopsida) from the Middle Devonian of North Xinjiang,China

Abstract According to newly collected and well preserved specimens, herbaceous lycopsids Colpodexylon gracilentum Dou and Colpodexylon laminatum Dou from the late Middle Devonian of Xinjiang, NW China are reduced to C. gracilentum, for which a neotype is designated and emended diagnosis is given. Colpodexylon gracilentum has leaves with three nearly equal segments, an elliptical sporangium adaxially attached by a pad on the isomorphic sporophyll.     

ARCHAEOPTERIS MACILENTA,ANATOMY AND MORPHOLOGY OF ITS FROND

The stem, rachides, and pinnae of Archaeopteris macilenta, formerly considered to be a fern of Devonian age, comprise a branch system in which the ultimate divisions heretofore referred to as pinnules are the leaves. The primary vascular system of the “frond” is a lobed siphonostele from which leaf traces arise in a spiral sequence. The anatomy of the “rachis” and of the “pinnae” is shown to be similar to that of the stem, Callixylon, which bore these “fronds.” Branching, epidermal pattern and stomates are described for the spirally arranged leaves (fertile pinnules). Attachment and dehiscence of sporangia as well as their stomates are reported. Archaeopteris is retained in the Class Progymnospermopsida which includes plants with gymnospermous anatomy and pteridophytic reproduction. It is suggested that Actinopodium, Svalbardia and Siderella are related closely to Archaeopteris and that this group of genera shows evolutionary stages in webbing of leaves and planation of branch systems. The opportunities for ontogenetic studies of the arborescent genus Archaeopteris are pointed out.     

The Middle Devonian lycopsid Haskinsia Grierson et Banks from the Ruppert Coast, Marie Byrd Land, West Antarctica

New observations on leaves of herbaceous lycopsid specimens previously attributed to Drepanophycus schopfii Mildenhall from Marie Byrd Land, West Antarctica, indicate that they belong to Haskinsia colophylla Grierson et Banks. Haskinsia was a wide spread lycopsid during the Middle Devonian.     

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.     

ACTINOXYLON BANKSII GEN. ET SP. NOV.: A PROGYMNOSPERM FROM THE MIDDLE DEVONIAN OF NEW YORK

A new genus from a Middle Devonian locality near Cairo, N. Y., is described. Actinoxylon gen. nov. is based upon pyritic petrifactions. Three orders of branching are present: penultimate branch, ultimate branch, and leaf. The penultimate branch bears spirally arranged ultimate branches and leaves, the leaves apparently replacing the branches in the spiral. The ultimate branches bear opposite to subopposite and decussate leaves. The leaves are non-planated, unwebbed structures which show at least three dichotomies. Each segment of the leaf is terete as are all other axes. Internally the penultimate branch has a six-lobed actinostele with mesarch protoxylem areas, one or two per lobe. Secondary xylem is visible in the oldest parts of several specimens. The xylem has helical-reticulate, reticulate, scalariform and circular-pitted elements. The presumptive areas of phloem are occupied by cells with dark contents. The cortex is composed of a parenchymatous inner region and a sclerenchymatous outer region. The ultimate branch traces are at first three-lobed protosteles, later becoming four-lobed. Several ultimate branch traces also possess secondary xylem while within the cortex of the penultimate branch. The leaf traces are terete strands. Below each forking of a leaf segment there is a corresponding forking of the vascular strand. Actinoxylon is compared with the progymnosperms Actinopodium, Svalbardia, Archaeopteris, Siderella, and Tetraxylopteris. The anatomy of the penultimate branch of Actinoxylon is similar to that of Actinopodium, Archaeopteris macilenta, and Siderella. The ultimate branch traces of Archaeopteris and Actinoxylon are similar. The ultimate branch stele and pattern of trace formation in Actinoxylon is similar to the stelar configuration and trace formation in the r + 2 axes of Tetraxylopteris schmidtii. The unwebbed leaves are similar to those of Archaeopteris fissilis, Svalbardia, and the terminal units of the Aneurophytales.     

A new Middle Devonian gasterocomid crinoid from central Turkey and revision of the Gasterocomidae

A juvenile cup, disarticulated arm plates, and columnals of the crinoid Arachnocrinus sarizensis n. sp. are described from the Eastern Taurus Mountains of central Turkey. This is the first Paleozoic crinoid based on a cup and arm plates reported from Turkey. Suggested revision of the Gasterocomidae includes transfer of Arachnocrinus and Ancyrocrinus to the family and rejection of Kopficrinus from the family. The stratigraphic range of Arachnocrinus is extended upward into the Middle Devonian from the Early Devonian. The Devonian of Turkey is of special interest because it includes Laurasian and Gondwanan components on different tectonic blocks. The paleogeographic range of Arachnocrinus is extended from the North American plate onto the Anatolian block, which would have been located on the southern edge of the Paleotethys Sea in the Middle Devonian in a shelf basin off the northern coast of Gondwana at approximately 42° south latitude.     

Clevelandodendron ohioensis,gen. et sp. nov., a slender upright lycopsid from the late Devonian Cleveland Shale of Ohio

Clevelandodendron ohioensis Chitaley & Pigg gen. et sp. nov. is an almost entire lycopsid plant known from a single compressed specimen from the Cleveland Shale member of the Upper Devonian Ohio Shale. This unique specimen is 125 cm long, consisting of an unbranched, slender, monopodial axis with a partially preserved plant base bearing thick appendages at one end, and a compact, terminal ovoid bisporangiate strobilus at the other. The stem is 2 cm wide for most of its length. Visible on the decorticated stem surface are helically arranged, elongate leaf traces and laterally compressed, slender leaves along the stem margin. The plant base bears 4-6 thick appendages. The terminal strobilus is compact, ovoid, 9 cm long and up to 6 cm wide, morphologically similar to those of some Lepidodendrales, and bears helically arranged sporophyll/sporangium complexes with narrow bases and distal laminae up to 18 mm long, turned upward. Megaspores are 320-360 μm, trilete and laevigate, lacking a gula; microspores are 30-42 μm, trilete, indistinctly punctate and possibly assignable to Calamospora or Punctatisporites. Clevelandodendron demonstrates that slender unbranched lycopsids with an isoetalean plant habit similar to the Carboniferous genera Chaloneria and Sporangiostrobus and Triassic Pleuromeia-like forms were present as early as the Late Devonian. The early occurrence of this unique habit suggests that diversification within the isoetalean clade sensu Rothwell and Erwin (including both Isoetales and Lepidodendrales) was well established prior to the Carboniferous.     

CALAMOPHYTON IN THE MIDDLE DEVONIAN OF NEW YORK STATE

Specimens of Calamophyton from the Middle Devonian Ashokan Sandstone near Kingston, Ulster County, N.Y., are shown to belong to C. bicephalum Leclercq and Andrews, a Belgian species. Steel needles and a stereoscopic binocular microscope were used to follow the path of the forking leaves and branching sporangiophores of the specimens through the matrix. The terete leaves dichotomized two to three times in more than one plane. Sporangiophores dichotomized once. Each branch bore three recurved lateral branches which in turn bore two sporangia. Each branch terminated in an elongate, filiform projection. Sporangia apparently dehisced longitudinally. Their walls were composed of elongate cells. Their spherical spores ranged from 86 to 166 μ in diameter and bore a trilete mark. Ornamentation consisted of coni and spinae up to 4.5 μ long. They resembled dispersed spores of Dibolisporites gibberosus var. major Richardson. This is the second occurrence of Calamophyton bicephalum and the first account of its spores. It is the second report of the genus in North America.     

Devonian Vertebrates From Colombia

Vertebrate remains are reported from the Emsian–Eifelian Floresta Formation and the Late Devonian (?Frasnian) Cuche Formation of north‐eastern Colombia. The material from the Floresta Formation is associated with a marine invertebrate fauna and includes an arthrodire and probably a rhenanid. Several vertebrate‐bearing localities are recorded from the Cuche Formation; vertebrates occur with plant remains and lingulid fragments. They include an acanthodian (Cheiracanthoides? sp.), a chondrichthyan (Antarctilamna? sp.), placoderms (Bothriolepis sp., Asterolepis? sp. and an undetermined groenlandaspidid or primitive brachythoracid arthrodire), a stegotrachelid actinopterygianand three sarcopterygians (a cosmine‐covered form tentatively referred to an osteolepidid, the porolepiform Holoptychiussp., and the rhizodontid Strepsodus? sp.). This assemblage suggests a Late Frasnian age and is surprisingly similar to Late Devonian vertebrate assemblages found in similar facies of Europe and North America, notwithstanding the presence of the Gondwanan chondrichthyan Antarctilamna?. key words: Vertebrata, Devonian, Colombia, South America, biostratigraphy, palaeobiogeography.     

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.     

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.     

First decapod crustaceans in a Late Devonian continental ecosystem

The origin and early diversification of decapod crustaceans and their expansion from marine to continental environments are key events in arthropod evolution. Rare fossil decapods are known from the Palaeozoic, and the earliest eumalacostracans with undoubted decapod affinities are the Late Devonian Palaeopalaemon and Aciculopoda, found in offshore marine deposits. Here, we describe a new species of the shrimp Tealliocaris found in floodplain and temporary pond deposits from the Famennian (Late Devonian) of Belgium, together with a rare Palaeozoic assemblage of other crustaceans (conchostracans, notostracans and anostracans) and chelicerates (eurypterids). Tealliocaris walloniensis sp. nov. documents the earliest occurrence of continental decapod crustaceans and indicates that decapods have been part of continental ecosystems at least since the Late Devonian.     

Stenolaemate bryozoans from the Geirud Formation (Upper Devonian/Lower Carboniferous) of Central Alborz (Iran)

Two bryozoan species are described from the Geirud Formation (Upper Devonian/Lower Carboniferous) of Central Alborz (Iran). Trepostome Schulgina mutabilis Troizkaya, 1975 is known from the Upper Devonian (Famennian) of Central Kazakhstan. The new species Ascopora geirudensis n. sp. is the earliest known representative of the rhabdomesine genus Ascopora Trautschold, 1876.     

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.     

Microconchid encrusters colonizing land plants: the earliest North American record from the Early Devonian of Wyoming,USA

Caruso, JA. & Tomescu, AM.F. 2012: Microconchid encrusters colonizing land plants: the earliest North American record from the Early Devonian of Wyoming, USA. Lethaia, Vol. 45, pp. 490–494. Plant fossils in the Early Devonian Beartooth Butte Formation (Wyoming, USA) are colonized by microconchid encrusters which are found on several plant taxa, at two fossil localities in the formation, and whose tube coil diameters range from 230 to 1170 μm. Colonization is densest on broad Drepanophycus devonicus stems where microconchid individuals encompassing broad size ranges co‐occur in close vicinity. This indicates exposure to microconchid colonization and, therefore, submergence of the plant material for relatively extended periods of time prior to burial. For in situ preserved Drepanophycus, this suggests that the plants grew partially submerged and their submerged parts were colonized by microconchids while still alive. In turn, this indicates that by the Early Devonian microconchids were colonizing freshwater environments. The Beartooth Butte Formation provides the first record of plant colonization by microconchids in North America and, along with only one other Early Devonian record from Germany, the oldest evidence for microconchids colonizing plant substrates. □Devonian, encrusters, microconchid, vascular plants, Wyoming.     

Trigonotarbid arachnids from the Lower Devonian (Siegenian) of Bürdenbach (Lahrbach Valley,Westerwald area,Rhenish Slate Mountains,Germany)

An association of trigonotarbid arachnids from Siegenian strata of Bürdenbach in the Westerwald is described. The Bürdenbach trigonotarbids are numerically dominated by a new genus and species, Spinocharinus steinmeyeri n. gen. n. sp., which is characterized by a rounded carapace with a unique pattern of thorn-like tubercles. A comparison with previously described Devonian trigonotarbids suggests that the new taxon is most probably assignable to the family Palaeocharinidae, which is well represented by the genus Palaeocharinus from the Scottish Rhynie cherts. This would constitute the first record of Palaeocharinidae from the Rhenish Devonian and contrasts sharply with previously described Emsian associations from the Rhenish Slate Mountains, which are dominated by archaeomartids. A rare archaeomartid, Archaeomartus cf. levis, occurs in association with the putative palaeocharinids.