Somaspidion hammapberon n.gen. n.sp. — ein Arachnide aus dem Oberkarbon der subvaristischen Saumsenke NW Deutschlands

A well preserved trigonotarbid abdomen, species-type of a new genus within the Eophryninae Karsch 1882 is described from the upper Horster Schichten (Westfalian B) of the Ruhr basin. This fossil can be taken as an additional example for the distribution and decline of early terrestrial evertebrate populations.     

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.     

A fossil trigonotarbid arachnid with a ricinuleid-like pedipalpal claw

A fossil trigonotarbid (Arachnida: Trigonotarbida) assigned to Palaeocharinus sp. from the Early Devonian (c. 410 Ma) Rhynie cherts of Aberdeenshire, Scotland, UK is described, specifically for a previously unrecognised feature of the distal end of the pedipalp. This exhibits a small chela formed from a movable, unpaired apotele articulating against a slightly shorter, fixed projection from the inferior surface of the tarsus. Among other arachnids, this morphology has only previously been observed in the rare and enigmatic Carboniferous—Recent taxon Ricinulei. This character offers explicit support for a monophylum (Trigonotarbida + Ricinulei); a hypothesis previously based on opisthosomal characters which (if correct) would draw Ricinulei within the so-called Pantetrapulmonata clade (i.e. spiders and their closest relatives). Our data is not consistent with Ricinulei’s traditional position as sister-group of mites (Acari) and is an example of how considering extinct taxa may help to resolve the position of a ‘difficult’ living group.     

The oldest Devonian circumpolar ray-finned fish?

Actinopterygians (ray-finned fishes) are the most diverse group of living fishes, but have a sparse Devonian fossil record restricted to low palaeolatitudes. Here we report a new actinopterygian from the Paraná Basin of Brazil, which occupied a circumpolar position in the Palaeozoic. Available geological evidence supports a Middle Devonian or older age for this taxon, which shares features of the mandibular symphysis with the latest Devonian Tegeolepis. A phylogenetic analysis resolves these two as sister taxa. This new record expands the palaeogeographic distribution of Devonian ray-fins and suggests that gaps in their fossil record might be filled by exploring poorly sampled high-latitude localities within the Malvinokaffric Realm.     

NEW CLADID AND FLEXIBLE CRINOIDS FROM THE MISSISSIPPIAN (TOURNAISIAN, IVORIAN) OF ENGLAND AND WALES

Abstract:  The modern study of fossil crinoids began with J. S. Miller who, in 1821, described specimens from southern England, nearby Wales and other regions, and named several common Early Carboniferous genera. Later, in 1950–60, James Wright monographed all known Early Carboniferous crinoids from the British Isles. In spite of such previous scrutiny, we recognize here two new genera among species already described: Glamorganocrinus gen. nov. (type species: Ophiurocrinus gowerensis Wright, 1960) from South Wales and Mendipocrinus gen. nov. (type species: Poteriocrinus latifrons Austin and Austin, 1847) from southern England. These new genera increase the number of advanced cladid genera in the Ivorian Substage of the Tournaisian in western Europe to 18, and the total number of crinoid genera to 36. A review of species assigned to Mespilocrinus has led to the recognition of M. granulifer De Koninck and LeHon, 1854 as a nomen dubium. A new species of Mespilocrinus , M. wrighti sp. nov., is described from the Ivorian of South Wales; this is the most highly derived species of the genus, as based on a phylogenetic analysis including ten species and 13 characters, with Pycnosaccus as the outgroup. A single, well-ordered tree resulted from this analysis. Interpretation of this tree suggests that the centre of evolution for Mespilocrinus was North America, where three species appeared during the Kinderhookian (early Tournaisian), rapidly achieving morphological disparity within the genus. This radiation event was part of the overall explosive radiation of crinoids following the Late Devonian mass extinction event when crinoid diversity was at a global minimum during the Frasnian. Recovery began during the Famennian, followed by an explosive radiation in the Tournaisian.     

On the Emsian (Lower Devonian) arthropods of the Rhenish Schiefergebirge: 1.Xenarachne, an enigmatic arachnid from Willwerath, Germany

A new fossil arachnid,Xenarachne willwerathensis n. gen., n. sp. is described from the Lower Devonian (upper Lower Emsian) Klerf-beds of Willwerath, Germany. This intriguing fossil has a pedicel and pygidium, indicating that it belongs to the tetrapulmonate arachnids, but cannot be referred with confidence to any particular order. It is placed as Tetrapulmonata incertae sedis, though has similarities to whip spiders (Amblypygi) and spiders (Araneae).Xenarachne could even represent a very early spider, though the Devonian arachnid fauna could have included taxa which did not belong in any currently recognised order.Xenarachne may be an example of just such a fossil.     

A reappraisal of the Palaeopantopoda with description of a species from the Jurassic

The Devonian fossil Palaeoisopus appears, in the light of recent evidence from newly found specimens, to be much nearer extant pycnogonids than previously surmised. The fossil record of the Pycnogonida is extended to the Jurassic on the basis of a long overlooked Solenhofen example. Most of the specimens ascribed to the common Solenhofen Phalangites cannot be pycnogonids, but it is possible that we are dealing with a complex of superficially similar fossils. A revision of the classification of the fossil pycnogonids (Order Palaeopantopoda) is suggested in the light of this new material.     

On Occurrence and Significance about the Fossil Plants from the Yuntaiguan Formation Located between Hunan and Hubei

This paper deals with the fossil plants from the Yuntaiguan formation located between Hunan and Hubei province. There are six genera and ten species (containing a new genus and five new species) to be discussed here, such as Protolepidodendron scha-ryanum Krejci, Barrandeina dusliana (Krejci) Stur, B. contigua sp. nov., B. lixianensis sp. nov., B. multistriata sp. nov., B. laxa sp. nov., Drepanophycus spinaeformis Goepp., “Protopteridium”? minutum Halle, Psilophyti4es sp. and Longostachys latisporophyllus gen. et sp. nov., etc. The appearance of this fossil flora concerned here can be correlated to the Protolepidodendron scharyanum-Barrandeina dusliana Assemblage. Among these fossil plants from Yuntaiguan formation, both the Protolepidodendron scharyanum and Barrandeina dusliana are also the index fossils, the prior was wide spread during the Middle Devonian in whole world and the other was only found at the late Middle Devonian in Europe. In the Yuntaiguan formation the genus Barrandeina containing no less than five species and, the other taxa were also found from the Middle or the late Middle Devonian. So that this formation should be referred to the late Middle Devonian in age and this conclusion corresponds with the result of spore-pollen analysis in the Xiushuigou formation, Xiongzi county, which is similar to the Yuntaiguan formation and has been referred to the Middle Devonian. In this paper, only four species of Barrandeina and one species of Longostachys have been described, those of the former have not been found before in China. The authors think; this will be significant on studying fossil plants and in comparison with the age of the strata.     

An ophiuroid trackway from the Lower Devonian Hunsrück Slate, Germany

A new trace fossil, Arcichnus saltatus , from the Lower Devonian Hunsrück Slate, Germany, is interpreted as the trackway of a protasterid ophiuroid, Taeniaster. The trackway consists of a series of horseshoe-shaped impressions, produced by a pair of arms, a feature characteristic of some ophiuroid trackways. This new trace fossil demonstrates that protasterids lived both infaunally and epifaunally.     

云南丽江早泥盆世棘鱼类微体化石的首次报道

记述了云南丽江县鸣音区阿冷初早泥盆世山江组 (Lochkovian EarlyPragian)和阿冷初组(Middle LatePragian)棘鱼亚纲微体化石。这些化石被归属于 4属 5种 ,其中包含 1新属 2新种。这是西藏—滇西区棘鱼类化石的首次报道。不同于华南区棘鱼类的组成 ,丽江早泥盆世棘鱼类以栅棘鱼目属种为主 ,缺少锉棘鱼目属种。它与国外对比 ,则与澳大利亚新南威尔士中部同时代的棘鱼类表现出较多的相似性     

Analysis of fossil bone organic matrix by transmission electron microscopy

A transmission electron microscope (TEM) study was initiated on samples of geological ages ranging from Devonian to Jurassic to analyse the ultrastructure of the organic matrix in fossil bones that have preserved a histological structure after demineralisation. All samples show a network of variably well-preserved fibrils. Within the sampling, the best results were obtained in two specimens: the scales of the Devonian sarcopterygian tetrapodomorph Eustenopteron foordi, and the humerus of Jurassic dinosaur Lappentosaurus madagascariensis. Despite an extended time difference between both specimens, their fossil bone is composed of a plywood-like structure in which the fibrils are very closely packed. These observations support the hypothesis that dense initial packing of collagen fibrils favours the preservation of the fossil bone.     

A new rhyniopsid with novel sporangium organization from the Lower Devonian of South Wales

SHUTE, C. H. & EDWARDS, D., 1989. A new rhyniopsid with novel sporangium organization from the Lower Devonian of South Wales. Re-investigation of permineralized plants originally called Cooksonia sp. from the Lower Old Red Sandstone (Siegenian) of Gwent, S. Wales shows them to be rhyniopsids with simple isotomous branching in smooth axes and ellipsoidal terminal sporangia that are longer than wide and that possess a complex wall organization. They are thus placed in a new genus. The sporangial wall is several cells thick, the outermost comprising a layer with pronounced thickening of the anticlinal and outer periclinal walls, which is interrupted by a zone of thinner-walled cells parallel to the longest dimension of the ellipsoidal organ and considered to be involved in its dehiscence into two equal halves. The alete isospores have a bilayered wall, the outer interpreted as an ornamented perispore. Similar granular ornament seen on sheets and globules in the vicinity of the spores and on the innermost surface of the sporangium wall possibly demonstrates the activity of a periplasmodial tapetum. The permineralized sporangia are considered conspecific with those in compression fossils with elliptical outlines and pronounced borders. Comparison of presumed dehiscence mechanisms in a number of Silurian and early Devonian fossils suggests that splitting into two equal valves along the longest dimension, so that a maximum area of spores was exposed to the atmosphere, arose independently in a number of unrelated plants.     

Deux Lycophytesavec structures conservées du dÉvonien supérieur D'Ukraine (U.R.S.S.)

A revision of fossil plants, with preserved structures, collected in the Upper Devonian of the Donetz Basin (Ukrainia) allows us to describe 2 Lycophyta. One of them is a new species: Colpodexylon (?) schopfii nov. sp.     

A NEW SEA SPIDER (ARTHROPODA: PYCNOGONIDA) WITH A FLAGELLIFORM TELSON FROM THE LOWER DEVONIAN HUNSRÜCK SLATE, GERMANY

Abstract:  A new Lower Devonian sea spider (Arthropoda: Pycnogonida) from the Hunsrück Slate, Germany, is described as Flagellopantopus blocki gen. et sp. nov. This is only the sixth fossil pycnogonid species to be described. Its most remarkable and unique aspect is the long, flagelliform telson. Although our fossil apparently lacks chelifores (an apomorphy), the retained telson and the segmented trunk end behind the last pair of legs resolve F. blocki to a fairly basal position in the pycnogonid stem lineage. It probably lies between Palaeoisopus problematicus Broili, which has a lanceolate telson and the most trunk segments of any sea spider, and all other Silurian–Recent Pycnogonida. Our new material shows that at least two fossil pycnogonids retained a telson, albeit with very different morphologies, and further supports the idea that a greater diversity of body plans existed among the Palaeozoic pycnogonid taxa.     

Evidence of land plant affinity for the Devonian fossil Protosalvinia (Foerstia)

The Devonian plant fossil Protosalvinia (Foerstia) has been examined by solid-state ¹³C nuclear magnetic resonance spectroscopy (NMR) and pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS). Results of these studies reveal that the chemical structure of Protosalvinia is remarkably similar to that of coalified wood. A well-defined phenolic carbon peak in the NMR spectra and the appearance of phenol and alkylated phenols in pyrolysis products are clearly indicative of lignin-like compounds. These data represent significant new information on the chemical nature of Protosalvinia and provide the first substantial organic geochemical evidence for land plant affinity. ▭ Protosalvinia, Foerstia, Upper Devonian, biostratigraphy, carbon-13 NMR, PY-GC-MS, lignin.     

An Early Devonian arthropod fauna from the Windyfield cherts, Aberdeenshire, Scotland

New terrestrial and freshwater arthropods are described from the Windyfield cherts, a suite of silicified sinters deposited 700m north‐east of the Rhynie cherts and part of the same Early Devonian hot‐spring complex. The diverse assemblage consists of Heterocrania rhyniensis (Hirst and Maulik, 1926a), here recognized as a euthycarcinoid; scutigeromorph centipede material assigned to Crussolum sp.; the crustacean Lepidocaris; trigonotarbid arachnids; a new arthropod of myriapod affinities named Leverhulmia mariae gen. et sp. nov.; and the distinctively ornamented arthropod cuticle of Rhynimonstrum dunlopi gen. et sp. nov. The Leverhulmia animal preserves gut content identifying it as an early terrestrial detritivore. Abundant coprolites of similar composition and morphology to the gut contents of the euthycarcinoid crowd the matrix. Chert texture, faunal associations, and study of modern analogues strongly suggest that the terrestrial arthropods were ubiquitous Early Devonian forms with no particular special adaptation to localized conditions around the terrestrial hot‐spring vents. The aquatic arthropods represent biota from ephemeral cool‐water pools in the vicinity of the hot‐spring vents.     

Arachniden-Neufunde im mitteleuropäischen Unterkarbon bis Perm — Beitrag zur Revision der Familie AphantomartidaePetrunkevitch 1945 (Arachnida, Trigonotarbida)

On the basis of rich new material covering a broad time span from the Lower Carboniferous (Viséan) to the Lower Permian (Asselian), the trigonotarbid family AphantomartidaePetrunkevitch 1945 is revised. According to investigations presented here it includes only one genus,Aphantomartus Pocock 1911, with two species,A. pustulatus (Scudder 1884) undA. areolatus (Pocock 1911). Many synonyms that existed in the literature until now, the stratigraphic occurrence, palaeobiogeographic distribution as well as taphonomic aspects are discussed. Besides some newly found as well as newly investigated specimens both the oldest and the youngest (the youngest trigonotarbid hitherto known) representatives of the family are presented.     

湖南湘乡上泥盆统佘田桥组介形类

本文首次报道了湖南湘乡上泥盆统佘田桥组介形类化石,共有１８属３５种及未定种,其中包括１１新种。通过与国内外泥盆纪和早石炭世介形类进行比较表明,它们与下伏的中泥盆统棋梓桥组介形类组合和上覆的上泥盆统锡矿山组介形类组合均有明显的差别,该介形类动物群的发现,为佘田桥组的地质时代的确定及地层的划分对比提供了新的古生物依据,并对研究介形类动物群的演化增加了新的资料。     

Bifungites, trace fossils from Devonian-Mississippian rocks of Pennsylvania and Montana,U.S.A

The trace fossil Bifungites Desio 1940, first recognized in Late Devonian rocks of Libya and later in Algeria, is common in Late Devonian rocks of Montana, Pennsylvania, Ohio, and Michigan, and Early Mississippian rocks of Pennsylvania. Its manifestations are given for seven stratigraphic units from forty localities in Pennsylvania, Montana, and Michigan.Bifungites commonly occur on bedding planes and consist of a horizontal shaft with doubly terminating arrow- or dumb-bell-shaped projections. Less apparent are paired vertical cylindrical sediment-filled tubes connected at their base to the bi-arrow or dumb-bell shaft. The combination represents the mud or silt casting of an inverted pi-shaped, μ, infaunal tubular burrow (domichnia). Siltstone slabs have been transversely sectioned to reveal this π-shaped, double-arrow burrow pattern with undisturbed stratification between the vertical tubes.Three new ichnospecies are proposed based on markedly different size and shape of the fossil traces in three stratigraphic zones. A Late Devonian Girard Shale type is the smallest with wide, short arrows on a narrow shaft whose median overall length is 12.5 mm. The latest Devonian Sappington type has well-formed, shortly barbed arrow terminations and median length of 28 mm. An Early Mississippian Meadville type is the largest with median length of 36 mm and prominently barbed broad arrows.The Bifungites organism is unrecognized but it was probably a sedentary, soft-bodied, infaunal suspension-feeding animal inhabiting shallow nearshore marine and brackish water environments. The identified biota directly or indirectly associated with Bifungites is extremely limited to a few brachiopods, clams, and other trace fossils.     

Do fossil plants signal palaeoatmospheric carbon dioxide concentration in the geological past?

Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo-carbon dioxide levels. This paper presents new estimates of palaeo-atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi-quantitative palaeo-carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present-day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo-carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long-term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced concentrations during the Late Carboniferous and Early Permian. Such data are important in demonstrating the long-term responses of plants to changing carbon dioxide concentrations and in contributing to the database needed for general circulation model climatic analogues.