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 Carcinosomatid Eurypterid From The Upper Silurian Of Northern Vietnam

A new carcinosomatid eurypterid, Rhinocarcinosoma dosonensis sp. nov., and Hughmilleria sp., are described from the Dô Son Formation of the Dô Son Peninsula, northern Vietnam. R. dosonensis is characterized by podomere 7 of prosomal appendage VI produced into an anterodistal spine, a metastoma with a cordate posterior margin, and an indented opisthosomal differentiation (i.e. preabdomen–postabdomen margin is concave). The Dô Son Formation was originally interpreted as Late Devonian (Givetian/Frasnian) in age but the unit containing the eurypterid assemblage is now considered much older (Late Silurian). A deltaic palaeoenvironmental setting is interpreted from biotic associations and sedimentological evidence.     

First record of eurypterids (Chelicerata,Eurypterida) from the Lower Devonian (Lower Emsian) Hunsrück Slate (SW Germany)

For the first time, fossils of unquestionable eurypterid origin are documented from the renowned Lower Devonian Hunsrück Slate Lagerstätte in southwestern Germany. The gnathobase of a coxal plate and a body segment can be attributed to pterygotid eurypterids, probably to Jaekelopterus rhenaniae. These body parts from the Hunsrück Slate once more confirm the extraordinary large size that could be attained by this Rhenish eurypterid. Based on the usual occurrence in marine–terrestrial transitional facies elsewhere in the Rhenish Devonian, rareness in the Hunsrück Slate, and poor preservation, the Hunsrück Slate pterygotid remains are most probably allochthonous, and eurypterids are considered nongenuine elements of the ‘Hunsrück Slate biota.     

Plant and animal cuticle remains from the Lower Devonian of southern Poland and their palaeoenvironmental significance

Filipiak, P. & Zatoń, M. 2010: Plant and animal cuticle remains from the Lower Devonian of southern Poland and their palaeoenvironmental significance. Lethaia, Vol. 44, pp. 397–409. Assemblages of plant and arthropod remains are reported from the Lower Devonian clastic deposits of the Upper Silesian and Ma?opolska blocks in southern Poland. Most of the plant and animal remains are palynologically dated as Pragian–Emsian/Eifelian. The plant material comprises higher plant cuticles with stomata classified as Drephanophycus and Sawdonia, and more enigmatic remains (nematophytes) classified as Nematothallus, Cosmochlaina and tubular banded tubes. They are associated with abundant and diverse miospores. Animal remains consist of eurypterid respiratory organs, the morphology of which may presumably point to their advance physiological properties, and cuticular remains of eurypterid and probably scorpion origin, as well as some remains of unknown affinity. The presence of such mixed assemblages in the Lower Devonian of Poland indicate marginal‐marine and/or alluvial environments spreading in the southern margin of the Old Red Continent. The dominance of land‐derived plant remains and simultaneous scarcity of marine acritarchs indicate that the environment was very weakly influenced by marine conditions. If nematophytes were really related to extant liverworts, as suggested by some workers, they, together with the other associated spore‐producing plants, may strongly indicate moist environmental conditions, which may have offered suitable habitats for temporary eurypterid migrations onto land. □Cuticles, eurypterids, Lower Devonian, nematophytes, Poland, spores.     

New species of the genus Adelophthalmus (Eurypterida, Chelicerata) found in the Middle Devonian of Khakassia

Two new eurypterid species, Adelophthalmus kamyshtensis sp. nov. and Adelophthalmus dubius sp. nov., are described from the Middle Devonian of Khakassia. The new species are among the earliest known members of the genus Adelophthalmus and the earliest members of this genus known outside Europe and North America.     

A new specimen ofWeinbergina opitzi (Chelicerata: Xiphosura) from the Lower Devonian Hunsriick Slate, Germany

A new specimen of the synziphosurine arthropodWeinbergina opitzi is described from the Lower Devonian (Lower Emsian) Hunsrück Slate of Germany (Rhenish Slate Mountains). It is the smallest and only the fifth specimen of this taxon to be described and is preserved in ventral aspect with exceptional preservation of prosomal and opisthosomal appendages. This specimen confirms the presence of a seventh appendage, similar in morphology to the preceding prosomal appendages, associated with opisthosomal segment one. In addition, at least three opisthosomal plates fringed with teeth are confirmed. Correlation of prosomal appendage podomeres betweenWeinbergina and selected chelicerate taxa shows that appendage structure is most similar to eurypterid appendages III–IV and Araneae appendages III–VI. This is in contrast to modern horseshoe crabs which have fewer podomeres in appendages II–V due to an undifferentiated tibiotarsus.      

THE EURYPTERID ADELOPHTHALMUS SIEVERTSI (CHELICERATA: EURYPTERIDA) FROM THE LOWER DEVONIAN (EMSIAN) KLERF FORMATION OF WILLWERATH, GERMANY

Abstract: The eurypterid Rhenopterus sievertsi Størmer from the Lower Devonian of Germany is redescribed. Based on new morphological data, including the possession of prosomal limbs of Adelophthalmus‐type and spatulae on the genital operculum, the species is transferred to Adelophthalmus Jordan, in Jordan and von Meyer and thus is the oldest representative of this geographically and stratigraphically widespread genus. Eurypterus? trapezoides Størmer is recognized as a junior synonym of A. sievertsi.     

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.     

On the Emsian (Lower Devonian) arthropods of the Rhenish Slate Mountains: 5. Rare and poorly known eurypterids from Willwerath, Germany

In addition to the previously known eurypterid taxa from Willwerath, remains ofParahughmilleria hefteri, Erieopterus sp., andJaekelopterus rhenaniae are described and figured. Body parts of small pterygotids are interpreted as representing juveniles ofJ. rhenaniae. To further substantiate this interpretation an analysis of telson ontogeny in the SilurianAcutiramus macrophthalmus of New York State, another well-known pterygotid, is included. As a result, it is suggested thatPterygotus juvenis is a juvenile and thus a junior synonym ofA. macrophthalmus. The genital appendages ofJ. rhenaniae show no segmentation and consequently the family Jaekelopteridae is rejected. The palaeoenvironment of the Willwerath eurypterid association, dominated byAdelophthalmus andRhenopterus, is interpreted as a shallow brackish to freshwater/terrestrial setting in a deltaic transitional facies. In contrast,Parahughmilleria-dominated eurypterid associations from the Rhenish Slate Mountains seem to be confined to lagerstätten where a marine influence is more obvious than at Willwerath.     

Chinese origin and radiation of the Palaeozoic crinoid family Petalocrinidae

The Ordovician to Devonian family Petalocrinidae includes 28 species belonging to 5 genera. This family is unique because the arm plates are fused into a large fan or cylinder. Paleobiogeographic occurrences of this family include Laurentia, Baltica, Avalonia, South China, Sibumasu, and Perunica blocks. The family has the oldest petalocrinids from China. An early radiation of this clade resulted in three genera during the Llandovery of China. Petalocrinus became cosmopolitan during the Llandovery and Wenlock, and the youngest genus is present in the Lower Devonian of the Czech Republic. Taxonomic determination for the Petalocrinidae is based on the fused arm plates instead of cup plates. The diverse morphology of these arm plates suggests a variety of aerosol suspension-feeding modes may have been used by petalocrinids.     

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.     

Reassessing Devonotarbus, a phalangiotarbid arachnid from the Lower Devonian (Siegenian and Emsian) of the Rheinisches Schiefergebirge (SW Germany)

Seven further specimens of the hitherto only known Devonian phalangiotarbid Devonotarbus Poschmann, Anderson and Dunlop, 2005 are described. Thus, the genus is recorded from four different localities of Siegenian (Hombach and Burglahr) and Lower Emsian (Willwerath and Alken) age, respectively, but the specific identity of Siegenian and Emsian specimens remains unproven. The new material suggests that this Devonian phalangiotarbid possessed more than six eye lenses, tergites five and six fused into a diplotergite, and an almost terminally situated anal operculum. It thus notably deviates morphologically from its younger Permocarboniferous relatives, and a new family, Devonotarbidae nov. fam., is proposed to accommodate Devonotarbus.     

New spiriferids (Brachiopoda) from the Lower and Middle Devonian of northeastern Russia

New spiriferids (Brachiopoda) are described from the Lower and Middle Devonian of northeastern Russia: Tatjanaspirifer iskrensis sp. nov. and T. magnificus sp. nov. (family Reticulariidae); Cyrtina inveterata Baranov, sp. nov. and Blodgettospirifer gen. nov. with type species B. lezhoevi sp. nov. (family Cyrtinidae).     

Giant claw reveals the largest ever arthropod

The fossil record has yielded various gigantic arthropods, in contrast to their diminutive proportions today. The recent discovery of a 46 cm long claw (chelicera) of the pterygotid eurypterid (‘sea scorpion’) Jaekelopterus rhenaniae, from the Early Devonian Willwerath Lagerstätte of Germany, reveals that this form attained a body length of approximately 2.5 m—almost half a metre longer than previous estimates of the group, and the largest arthropod ever to have evolved. Gigantism in Late Palaeozoic arthropods is generally attributed to elevated atmospheric oxygen levels, but while this may be applicable to Carboniferous terrestrial taxa, gigantism among aquatic taxa is much more widespread and may be attributed to other extrinsic factors, including environmental resources, predation and competition. A phylogenetic analysis of the pterygotid clade reveals that Jaekelopterus is sister-taxon to the genus Acutiramus, and is among the most derived members of the pterygotids, in contrast to earlier suggestions.     

New Devonian Palliocerida (Cephalopoda, Astrovioidea)

Eight new species of Ostreioceratidae are described from the Lower and Upper Devonian of Novaya Zemlya, Lower Devonian of the Pechora River basin, North Ural Mountains, and the Zeravshan Range: Ostreioceras admotum, O. simile, O. abruptum, O. sobolevi, Plagiostomoceras kuzmini, P. adumbratum, P.? acerbum, and P. vinogradovi. A new family Bogoslovskyidae is established in the order Palliocerida.     

Discussion of the Early Devonian rhynchonellid brachiopod genus Borealirhynchia Su, 1976

The Early Devonian brachiopod genus Borealirhynchia was established by Su, 1976. Phylum Brachiopoda (Cambrian to Devonian). In: Paleontological Atlas of North China, Inner Mongolia Volume 1. Geological Publishing House Beijing, pp. 155-227 (in Chinese). It has not been previously described in detail, nor have transverse serial sections of the internal features of Borealirhynchia delerensis, the type species, been published. In this paper Borealirhynchia, along with a few species previously assigned to it, is analysed and discussed. Detailed transverse serial sections of the internal features of B.? lata Su, 1976, are provided, based on well-preserved specimens collected from the Lower Devonian strata of Dong Ujimqin Qi, northeastern Inner Mongolia. Borealirhynchia? gigantea Su, 1976 and Latonotoechia multicosta Su, 1976 are considered to be synonyms of B.? lata Su with the same external and internal characters present in all three species. Some Lower Devonian strata, in which Borealirhynchia was found and reported, from Dong Ujimqin Qi, northeastern Inner Mongolia, are fully described.     

A New Eurypterid (Chelicerata: Eurypterida) from the Upper Devonian Gogo Formation of Western Australia, With A Review of the Rhenopteridae

A new eurypterid, Rhenopterus waterstoni sp. nov., is described from the Gogo Formation (Frasnian, Upper Devonian) of Western Australia. This species is distinguished from related forms by the tuberculation of the anteriormost tergite and crenulated posterior margins of the carapace and opisthosomal segments. It is the only eurypterid specimen known from the Gogo Formation, the most complete eurypterid from Australia, and also the youngest representative of Rhenopterus in the fossil record. Structures retrieved from between the prosomal-opisthosomal juncture comprise polygonal tubes 30–40 μm in diameter, which are interpreted as sarcomeral sheaths of muscular tissue. Rhenopterus is reviewed: R. latus Størmer, 1936 is synonymized with R. diensti Størmer, 1936 as it is here recognized as a female sexual dimorph; R. maccarthyi (Kjellesvig-Waering, 1934) is an orthocone nautiloid.     

New Lower Devonian brachiopods of the family Reticulariidae Waagen (order Spiriferida) of northeastern Russia

New Lower Devonian brachiopod taxa of the family Reticulariidae (order Spiriferida) are described from northeastern Russia: Havlicekospirifer gen. nov. with the type species H. mirabilis sp. nov. (subfamily Reticulariinae) and Pavlovispirifer gen. nov. with the type species P. pelagicus sp. nov. (subfamily Rhenothyridinae).     

Tube foot preservation in the Devonian crinoid Codiacrinus from the Lower Devonian Hunsrück Slate,Germany

Fossilized tube feet are described on Codiacrinus schultzei Follmann from the Lower Devonian Hunsrück Slate of Germany. This is the first definitive proof of tube feet on any fossil crinoid. Three lightly pyritized, flattened tube feet are preserved in a single interray of this cladid crinoid. The tube feet were at least 7 mm long. Their preservation is very similar to the tube feet reported previously from a Hunsrück ophiuroid, except that the Codiacrinus tube feet have small papillae, similar to living crinoids.     

Pentamerids (Brachiopoda) from the Lower and Middle Devonian of Northeastern Asia

Pentamerids (Brachiopoda) are described from the Lower and Middle Devonian of northeastern Asia: Antirhynchonella cherkesovae sp. nov. belonging to the family Clorindidae and Devonogypa indigirica (Sidjachenko), Vadimia gen. nov. with the type species V. gonensis sp. nov. and V. naanchanensis sp. nov., and Vladimiria gen. nov. with the type species Vl. yanensis sp. nov. all belonging to the subfamily Devonogypinae.