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

A new agelacrinitid edrioasteroid, Sumrallia rseiberti gen. et sp. nov., is introduced. Its morphology, with respect to different ontogentic stages, is described and figured, and its systematic position is discussed. Furthermore, synecological interactions of this edrioasteroid with brachiopods, bryozoans, and auloporid corals are documented. The new taxon supplements the highly diverse and extraordinarily well-preserved edrioasteroid fauna from the Holzbach Valley at Seifen in the Westerwald (Siegenian, Rhenish Slate Mountains).

Neubeschreibung des Originalmaterials von Pleurodictyum petrii Maurer 1874, der Typus-Art von Petridictyum Schindewolf 1958 (Tabulata; Unter-Devon, Rheinisches Schiefergebirge)

Akkretionäre Lapilli aus dem Haupt-Vulkanit (Unter-Devon) des Ebbe-Sattels (Rheinisches Schiefer­ gebirge, Blatt Meinerzhagen 4811)

A new specimen of the synziphosurine arthropodWeinbergina opitzi is described from the Lower Devonian (Lower Emsian) Hunsruck 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.

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 lagerstatten where a marine influence is more obvious than at Willwerath.

Cephalaspiden (Osteostraci) aus dem Unterdevon (Emsium) von Waxweiler (Rheinisches Schiefergebirge, Deutschland)

The diplobathrid camerate crinoid genus Monstrocrinus is morphologically reinterpreted on the basis of new finds from the upper Emsian (Lower Devonian) to lower Eifelian (Middle Devonian) of Germany (Rhenish Slate Mountains, North Rhine-Westphalia, and Rhineland-Palatinate). The most complete, new specimen has a long segment of column projecting outward from the basal concavity, which confirms that the Monstrocrinus crown was attached to a column as an adult. Thus, a free-living life mode of a passively rolling or drifting crinoid is refuted and Monstrocrinus is reinterpreted as an attached, stalked echinoderm. This finding is supported by re-examination of the historical type material. A column attachment with a central pentalobate axial canal was recognized for the first time in the calyx of the holotype of the type species Monstrocrinus securifer. The holotype of Monstrocrinus granosus is far more complete than previously thought. It is a partially disarticulated crown embedded together with an associated longer part of the column. The extraordinary spines on the calyx plates of Monstrocrinus can be divided into eight morphological types and into two superordinate categories: “Category A” is a physical part of the calyx plate, whereas “Category B” is an attachment onto the calyx plate. Taxonomically, M. aliformis from the upper Emsian of Spain is treated herein as a subjective junior synonym of M. securifer.

Furthermore, also the captions of Figure 2 and 3 contained printing errors. The correct Figure captions are reproduced in full below. We apologize for these errors.

Periglacial transport distance of Pb derived from small-scale ore veins in the Rhenish Slate Mountains

Abstract: A new terebratulid brachiopod species, Rhenorensselaeria jansenii, has been identified in the Merzâ‐Akhsaï Formation of the Dra Valley, Morocco, and the Grauwacke de Montguyon of the Amorican Massif, France. It is compared with the other known species of Rhenorensselaeria from Europe, Rh. strigiceps and Rh. demerathia, as well as with Rh. macgerriglei from North America, from which it differs in being larger and having coarser costae. Its possible life habit in clusters and its fossil community are compared with those of Rh. strigiceps from the Rheinisches Schiefergebirge (‘Rhenish Slate Mountains’), Germany, which it most resembles. A new phylogeny of the subfamily Rhenorensselaerinae is constructed. The close phylogenetic relationship between Rh. jansenii and Rh. strigiceps confirms close palaeobiogeographical relationships between North Africa, France and the Rheinisches Schiefergebirge as well as a wider relationship between Central Europe and Gaspé, eastern Canada, during the Early Devonian. Taxa of Rhenorensselaeria are mainly restricted to the Middle and Upper Siegenian, although rare individuals have been found in the Lower Emsian of Central Europe and North America. Because of their abundance in the Dra Valley and Rheinisches Schiefergebirge and their short life span, rhenorensselaerid taxa can be regarded as important stratigraphical markers of Middle–Late Siegenian and Early Emsian sediments in North Africa and Central Europe.

Zur Unterdevon-Gliederung im Rheinischen Schiefergebirge

New material of the trigonotarbids Alkenia and Archaeomartus from the Lower Devonian type locality Alken an der Mosel/Germany is described. Stormer’s original description of Alkenia is essentially confirmed and supplemented. The genus is placed in Aphantomartidae. In contrast to earlier accounts, we show that Archaeomartus has an anterior diplotergite and a longitudinally three-divided posteriormost (ninth) tergite. The new family Archaeomartidae is proposed. Whether a marginal row of larger tubercles on the opisthosoma can be recognized is strongly influenced by the taphonomic history of the fossil, and sexual dimorphism may also be involved. Thus, we propose that Archaeomartus levis and A. tuberculatus, which can be discriminated solely by the presence or absence of this feature, are synonyms. Furthermore, morphological similarity suggests the possibility that archaeomartids, with their opisthosomal tergites divided into three plates, gave rise to the later (Carboniferous) anthracomartids, specifically through the division of the lateral plates and the ninth tergite. Finally, our reassessment of Archaeomartus shows that ‘A.’ roessleri Dunlop and Brauckmann, 2006 can no longer be adequately maintained in this genus. This younger species from the early Upper Carboniferous of Hagen-Vorhalle, Germany, is reassigned to Namurotarbus n. gen. as Namurotarbus roessleri n. comb.

A new trigonotarbid (Arachnida: Trigonotarbida) Arianrhoda bennetti gen. et sp. nov. is described from the Lower Devonian (Lochkovian) of a quarry near Tredomen, Powys, mid Wales, UK. This relatively complete specimen is the first record of a pre‐Carboniferous arachnid from Wales, one of only a handful of early Devonian arachnids, and the second oldest trigonotarbid recorded. Based on the rounded prosomal dorsal shield and the relatively narrow, elongate opisthosoma we refer this new fossil to the family Anthracosironidae. A distinct flange‐like ornament on the leg 4 tibia in the new fossil is unique among trigonotarbids and is the primary autapomorphy for the new genus.

The fossil scorpionWaeringoscorpio hefteriStormer, 1970 (Arachnida: Scorpiones) from the Lower Devonian of the Rhenish Massif of Germany is redescribed based on both the original type and newly collected material. A second, more tuberculate species from Siegenian strata near Burdenbach in the Westerwald (also part of the Rhenish Massif) is described asW. westerwaldensis n. sp. Details of the coxo-sternal region — including the lack of an oral tube — and the number of ventral mesosomal plates are discussed.WaeringoscorpioStormer, 1970 is best known for its possession of externally-projecting ‘gills’. Our new material reveals that these are indeed pair-wise bundles of rigid, branching filaments which originate laterally, quite possibly from those segments of the mesosoma associated with the book lungs in extant scorpions. Their gross morphology is most consistent with a respiratory organ adapted for use in water. Indeed their closest modern analogues are the tracheal gills of secondarily aquatic insects. We suggest that the morphology and likely palaeoenvironment ofWaeringoscorpio could indicate an aquatic animal, but we draw attention to the uniqueness of its gill-structures, which may not be part of the scorpion ground-pattern. Thus,Waeringoscorpio was perhaps a secondarily aquatic scorpion adapted for benthic life in oxygen-stressed, freshwater-brackish environments.

Increased deposition of reactive nitrogen (N) since pre-industrial times has dramatically altered the conditions for forest growth and decomposition of organic material in Germany. The second National Forest Soil Inventory (NFSI II, 2006–2008) shows the status of N accumulation in forest soils. A median N stock of 6.3 t ha–1 has been found in the soil profile down to a depth of maximum 90 cm, whereof 50% is stored in the upper 30 cm of the mineral soil. The high regional variability of N stocks is explained by forest type, parent material, soil acidity, annual mean temperature, and adjacent agricultural land use. C/N ratios of the top soil were on average higher (24.0) than those during NFSI I (22.4, 1989–1992), which may be seen as a first effect of slowly decreasing deposition rates. Observations on limed plots suggest that acidification inhibits soil biological activity and thereby reduces N-storage in the mineral soil. The median annual N balance for German forest soils between NFSI I and II varies between +2.9 and +7 kg ha–1, depending on the harvest regime assumed. Negative N balances occurred mainly in mountain ranges like the Black Forest or the Rhenish Slate Mountains. N stocks in the upper 30 cm of the soil generally increased, while there are indications for losses of N from deeper soil layers, potentially linked to progressing acidification in these layers. Irrespective of existing measurement uncertainties, the findings indicate the vulnerability of forest N stocks under changing conditions. Further reductions of N deposition should be strived for to reduce the risk of nitrate leaching from forest soils.