Early Tithonian entactinarian Radiolaria from the Solnhofen area (southern Germany). Part I

The article describes part of the Entactinaria radiolarians from a very rich and well-preserved radiolarian assemblage extracted from a lower Tithonian sample (Mue 22) collected from the Mühlheim Member of the Mörnsheim Formation of southern Germany. With a single exception (genus Odoghertites nov. gen.), all other Entactinaria described are of primitive type, that is their initial spicules are not differentiated into an apical and a basal group and are not connected by arches to form a heteropolar “microsphere”. They have been assigned to five families, four of which are new (Isometractiniidae, Triumbraculidae, Hollandocachoniidae, Odoghertitidae), 10 new genera (Isometractinia, Triumbraculum, Tardentactinia, Lententactinia, Hollandocachonia, Sphaerentofurca, Stylentofurca, Zuegelifurca, Spongentofurca, Odoghertites), and 19 new species. One of the new species comes from the lower Bajocian of Oregon. A new skeletal structural term, support structure, is introduced as a special type of connection between the primary spines and the macrosphere or cortical shell.     

Discovery of a radiolarian fauna from the tithonian of the solnhofen area (Southern Franconian Alb, southern Germany)

A highly diverse and well preserved radiolarian fauna from the Mörnsheim Formation (Altmühltal Group, Lower Tithonian) of the Solnhofen area (Southern Franconian Alb) is presented. Herein, only well-known species are selected from a rich fauna with presumably numerous new taxa. Some of these species show additional morphological features, missing or rudimentarily developed due to preservation in previously described specimens. The selected species are stratigraphically classified according to international Unitary Association Zones.     

Bats (Chiroptera, Mammalia) from Middle Miocene karstic fissure fillings of Petersbuch near Eichstätt, Southern Franconian Alb (Bavaria)

The bats from the karstic fissure fill sites Petersbuch 6, 10, 18, 31, 35 and 48 include 14 species, four of which are new. All samples are numerically dominated by rhinolophids, especially by Rhinolophus delphinensis. The rich samples from Petersbuch 6-18 are striking in their high species diversity (seven species each). Myotis bavaricus nov. sp. is characterised by a series of plesiomorphous characters, while Myotis reductus nov. sp. is more derived. A special trait of Submyotodon petersbuchensis nov. gen. nov. sp. is the coexistence of nyctalodont and (sub-) myotodont molars in one dentary. Miniopterus rummeli nov. sp. is characterised by its large size, a high coronoid process and its widely spaced lower premolars. Composition and origin of the chiropteran faunas are discussed. They are interpreted as an accumulation of bats that perished in the cave or rock crevice and to a negligible extent as remains of owl pellets. The stratigraphic correlation of the faunas, based on rodents, is late Middle Miocene (MN 7/8). This study is based on several thousand specimens.     

Lower Cambrian (Botomian) polycystine Radiolaria from the Altai Mountains (southern Siberia, Russia)

Relatively well-preserved polycystine Radiolaria are here described from Lower Cambrian (Botomian) strata of the Shashkunar Formation, Altai Mountains in southern Siberia (Russia). These radiolarians display a test formed of a disorderly and three-dimensionally interwoven meshwork of numerous straight and curved bars branching from a five-rayed point-centered spicule located within the inner shell surface. The shell structure allows their assignment to the family Archeoentactiniidae, thus extending the known age range of the family down to the Lower Cambrian. The Botomian age is based essentially on trilobites (Parapagetia-Serrodiscus zone), but also on archaeocyathids identified in earlier publications. The study of the radiolarian-bearing sedimentary sequence confirms the presence of polycystine radiolaria in the external platform environments of Lower Cambrian ecosystems.     

Sedimentology,taphonomy, and palaeoecology of a laminated plattenkalk from the Kimmeridgian of the northern Franconian Alb (southern Germany)

At Wattendorf in the northern Franconian Alb, southern Germany, centimetre- to decimetre-thick packages of finely laminated limestones (plattenkalk) occur intercalated between well bedded graded grainstones and rudstones that blanket a relief produced by now dolomitized microbialite-sponge reefs. These beds reach their greatest thickness in depressions between topographic highs and thin towards, and finally disappear on, the crests. The early Late Kimmeridgian graded packstone–bindstone alternations represent the earliest plattenkalk occurrence in southern Germany. The undisturbed lamination of the sediment strongly points to oxygen-free conditions on the seafloor and within the sediment, inimical to higher forms of life. The plattenkalk contains a diverse biota of benthic and nektonic organisms. Excavation of a 13 cm thick plattenkalk unit across an area of 80 m² produced 3500 fossils, which, with the exception of the bivalve Aulacomyella, exhibit a random stratigraphic distribution. Two-thirds of the individuals had a benthic mode of life attached to hard substrate. This seems to contradict the evidence of oxygen-free conditions on the sea floor, such as undisturbed lamination, presence of articulated skeletons, and preservation of soft parts. However, palaeoecological and taphonomic analyses indicate that the benthic faunal elements are allochthonous having settled out of suspension and thus must have been derived from hard substrate areas of neighbouring topographic highs. Solely the bivalve Aulacomyella, which occurs concentrated on a single bedding plane, may have colonised the plattenkalk depression during brief periods of oxygenation. Alternatively, a pseudoplanktonic mode of life, attached to floating sea weed, is envisaged for the bivalve. The formation of the plattenkalk is related to local and global factors: a drop in relative sea level caused the death of the microbialite-sponge reefs. Restricted circulation in depressions between the crests of the former reefs led to anoxic conditions and the formation of finely laminated sediments stabilised by microbial mats. The small depressions received sediment and skeletal elements of benthic organisms that were swept off neighbouring topographic highs by storms and that entered the depressions partly as turbidity currents, partly as suspension clouds. A rise in the relative sea level finally terminated the restricted circulation in the depressions and closed the taphonomic window that led to the preservation of the plattenkalk biota.     

Fluvival tufa formation in a hard-water creek (Deinschwanger Bach, Franconian Alb, Germany)

Summary Cyanobacteria-dominated biofilms involved in tufa deposition in the hardwater creek Deinschwanger Bach, Bavaria, were investigated with regard to their effect on the carbonate equilibrium and fabric formation. Current tufa deposition is evident by up to 1.5 mm thick crusts that have formed on substrate plates placed in the creek for 10 months. Hydrochemistry data indicate that carbonate precipitation along the creek is physicochemically driven by CO₂ degassing, whereas photosynthetic carbon assimilation is without detectable effect on the macroscale carbonate equilibrium. However, stable isotope data indicate a minor photosynthetic effect, but only for the lower creek section where the pCO₂ already drops to the two-fold of the atmospheric level. Though the initial process of external nucleation on cyanobacterial sheaths in the lower creck section might be promoted of by a photosynthetically-induced microscale pH gradient, the effect is not strong enough to cause a CaCO₃ impregnation of the sheaths. The fabric of the laminated tufa crusts in the creek reflects the temporal alternation of porous microspariticPhormidium incrustatum-Phormidium foveolarum-diatom biofilms in spring, micrite-impregnatedPhormidium incrustatum-Phormidium foveolarum-diatom biofilms in summerautumn, and detritus-rich non-calcified diatom-biofilms in winter. By contrast, exopolymer-poor surfaces of cascade tufa mosses show large, euhedral spar crystals. Non-phototrophic bacteria, which occur in large numbers inPhormidium incrustatum-Phormidium foveolarums-diatom-communities, thrive on extracellular polymeric substances (EPS) and dead cells of the cyanobacteria and are unlikely to promote CaCO₃ precipitation.     

Late Paleocene Phaeodaria (Radiolaria) from Denmark

The article reports the finding of some late Paleocene (Thanetian) species of Phaeodarian Radiolaria in phosphorite concretions occurring in the Holmehus Formation of Denmark. These species are associated with a rich assemblage of diatoms and sparse spherical radiolarians. Phaeodarians are very well-preserved in celestobarite (BaSrSO₄) and consist of representatives of the families Challengeridae (Challengerebium triangulovum nov. sp. and Challengerebium sp.) and particularly Medusettidae (Medusetta danica nov. sp. and M. densicostata nov. sp.), which are the most frequent. A new genus of medusettid phaeodarians (Pseudochallengeranium nov. gen.) is also described.     

Late Tithonian nannofossils from Dejen area,the Blue Nile Basin,central western Ethiopia

The Jurassic rocks exposed in the Blue Nile Basin (central western Ethiopia), particularly the thick, fossiliferous and widely distributed Antalo Limestone Formation (ALF) has recently been dated between early Callovian and late Tithonian based on the occurrence of calcareous nannofossils from the Mugher section near Dejen, Ethiopia. However, the top part of the ALF is not well exposed at Mugher; in this study, the top part of the ALF was sampled at the Kurar section (150 km north of Mugher). It yielded a nannofossil assemblage containing Helenea chiastia, whose first occurrence (FO) marks the base of the Tithonian NJT16a calcareous nannofossil subzone, and Faviconus multicolumnatus, whose FO is near the base of the NJ15b subzone and corresponds with the FO of the Tithonian zonal marker Polycostella beckmannii recorded at the Mugher section. This age is also corroborated by the presence of recently recorded calpionellids (Bonetinae subzone) and the presence of late Tithonian ammonites, Djurjuriceras cf. sinuosum Tavera and Oxylenticeras Spath from the Kurar section. Hence, the upper part of the ALF exposed at the Kurar and Mugher sections are of late Tithonian age, although at the Mertule Mariam section (60 km northwest of the Kurar section), late Berriasian calpionellids were recently found from the top part of the ALF.     

A Long Mortichnial Trackway of Mesolimulus walchi from the Upper Jurassic Solnhofen Lithographic Limestone near Wintershof,Germany

A 9.7 m long trackway was discovered in a plattenkalk quarry near the village of Wintershof, Bavaria, Germany, in 2002. The huge ichnofossil derives from the Lower Tithonian, Upper Jurassic Solnhofen Lithographic Limestone. The trackway is complete from beginning to end and consists of footprints, telson drag impressions, prosoma imprints and is identified as the ichnotaxon Kouphichnium isp. Preserved at the very end of the trackway is a complete specimen of Mesolimulus walchi confirming the trackway as a mortichnia (death march). Trackways and trace makers preserved together in the fossil record are rare and such specimens allow unique insights into behavior and ecology. The events that led to M. walchi preserved in this sediment are unknown; however, a most likely scenario is that the limulid was washed into the lagoonal environment during a harsh storm.     

Lagomorphs from the Miocene of Sandelzhausen (southern Germany)

Three genera of lagomorphs, Prolagus, Lagopsis, and “Amphilagus,” were identified during a revision of the lagomorph material from Sandelzhausen (MN5, Early/Middle Miocene boundary, southern Germany). Evidence of two morphological and dimensional classes were observed at some tooth positions in Prolagus (some p3 show an unmistakable P. oeningensis morphology, others closely resemble P. crusafonti), but not at other tooth positions (e.g., M1–2). Insufficient data from Sandelzhausen precludes identification of two different species of Prolagus from this locality, and to define the characteristics of the possible P. crusafonti-like species. Thus, all Prolagus specimens have been classified as P. aff. oeningensis. The genus Lagopsis is represented by L. cf. penai, whose presence is compatible with a MN5 age. The relative abundance of Lagopsis to Prolagus may indicate relatively cool and wet palaeoclimatic conditions. The largest primitive lagomorph species from continental Europe is present at Sandelzhausen. Morphological and dimensional comparisons with other European primitive lagomorphs exclude any affinity with the genera Eurolagus and Titanomys and with the species included in “Amphilagus ulmensis”. Some common features with “Amphilagus antiquus” were observed, although they are not sufficient for the attribution to this taxon. Until there is a general revision of European primitive lagomorphs, the Sandelzhausen giant lagomorph is classified as “Amphilagus” sp. Its origins, whether from evolution within Europe or migration from Asia, remain unknown.      

Microfacies-based provenance analysis of Roman imperial mosaic and sculpture materials from Bavaria (Southern Germany)

Summary Microfacies-based provenance analysis of Roman mosaics found in Southern Bavaria near Augsburg indicates the use of Mesozoic carbonates and sandstones occurring as boulders within Pleistocene and Holocene deposits near to the mosaic sites. In addition, local allochthonous Late Jurassic ooid-peloid grainstones were used for the fabrication of white tesserae. Microfacies criteria provide a means for evaluating the original location of sculptures as demonstrated by the study of the head of a Roman Goddess made of Alpine Late Triassic limestone.     

A review of bipolarity concepts: History and examples from Radiolaria and Medusozoa (Cnidaria)

Bipolarity, its history and general interpretation are investigated and discussed herein. Apart from the classical view, namely that a bipolar distribution is a peculiar biogeographical phenomenon, we propose that it is ecologically controlled too. This approach was used for bipolarity assessment within the following groups: Phaeodaria, Nassellaria, Spumellaria (Radiolaria) and Medusozoa (Cnidaria). We recognize 46 bipolar radiolarian species and three radiolarian genera. However, although species concepts in radiolarians are relatively stable and well known, the high-rank taxonomy of radiolarians is still not well defined. Caution should therefore be taken in the interpretation of distribution data at a taxonomic level higher than the species. In the Medusozoa, bipolarity is observed for 23 species and 32 genera. The different ways in which bipolarity can develop are discussed under the different groups, but preference has been given to the recent and most probable routes of migration. In our investigation of the bipolarity phenomenon, we reviewed more than 400 articles dealing with taxonomy, ecology and biogeography of the modern fauna in both groups.     

Early jurassic (Upper Pliensbachian) gastropods from the Herforder Liasmulde (Bielefeld, Northwest Germany)

An Early Jurassic (Upper Pliensbachian) gastropod fauna from the Herforder Liasmulde (Herford Lias Syncline) near Bielefeld, Northwest Germany is described. This is one of the first detailed and illustrated reports of Pliensbachian gastropods from this area. Sixteen species are reported. Surface collecting yielded relatively large vetigastropods (pleurotomarioids amd trochomorphs). Bulk samples yielded abundant small caenogastropods (especiallyLevipleura blainvillei andKalchreuthia frankei) and cylindrobullinid opisthobranchs (e.g.Cylindrobullina dornend). These small species are also abundant in the Pliensbachian of South Germany (N Bavaria, Franconia). Therefore, this characteristic Pliensbachian microgastropod assemblage was widespread in Germany and probably also in other comparable marine deposits of Central Europe (e.g. the Paris Basin).      

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.      

Diversity and palaeoecology of the enigmatic genus Knebelia (Eucrustacea,Decapoda, Eryonidae) from Upper Jurassic plattenkalks in southern Germany

For a long time, the genus Knebelia Van Straelen, 1922 has comprised two species of eryonid lobster, K. bilobata (Münster, 1839) and K. schuberti (Meyer, 1836), both recorded exclusively from Late Jurassic Lagerstätten in southern Germany. Recently, the latter has been suggested to represent a juvenile individual of Cycleryon propinquus (Schlotheim, 1822). A re‐examination of the type and new material has led to our rejection of that interpretation and confirmation of assignment of this species to Knebelia. Two specimens, both possessing short frontal lobes, from plattenkalks at Nusplingen (late Kimmeridgian) and at Solnhofen (early Tithonian), respectively, are here assigned to a new species, K. totoroi sp. nov. This new species and a review of K. bilobata have furnished new insights into the origin and function of the frontal lobes, which are expansions articulated to the front of the carapace. They probably functioned as rudders facilitating ‘tail‐flip swimming’ as observed in the paddle‐like antennae of extant scyllarids (Eucrustacea, Decapoda, Scyllaridae). The rudder‐like lobes identified in Knebelia may therefore represent a case of convergent evolution.     

Fishes from the Akkuyu Formation (Tithonian),Western Taurus,Turkey

Two fragmentary fishes are described from theUpper Jurassic (Tithonian) Akkuyu Formation of the Akseki region in the western Taurus (Turkey). Both are determinable, one as a caudal fin of an ichthyodectiform teleost, either Thrissops or Allothrissops, the other as a coelacanthid coelacanth, cf. Undina. This discovery extends the geographic range of these taxa and draw attention to the possibility of collecting a more extensive fish fauna from the region.     

Late-glacial fluctuations of timberline in the Black Forest (SW Germany)

Based on pollen diagrams from nine sites at altitudes between 654 and 1280 m a.s.l. the Late-glacial fluctuations of the timberline are reconstructed and interpreted in terms of summer temperature.     

The identity of the type specimen ofCoelacanthus harlemensis Winkler (Pisces,Actinistia) from the lithographic limestone of Solnhofen (Tithonian), Bavaria

The type specimen ofCoelacanthus harlemensis Winkler 1874 is redescribed. It belongs toCoccoderma suevicum Quenstedt, 1858. The fossil is the first complete specimen of this species described and figured.     

Sequence stratigraphy and paleo-oceanography of an open-marine mixed carbonate/siliciclastic succession (Late Jurassic,Southern Germany)

Summary The Late Jurassic epicontinental sea of South Germany protruded far to the North forming a wide bay which was rimmed by shallow-water platforms (Swiss and French Jura). This wide shelf is characterized by extensive downslope mud accumulations including siliceous sponge buildups. The bioherms are aligned along the more pericontinental parts of this shelf, which graded to the South into the Helvetic Basin of the Tethys Ocean. Five sedimentary cycles of Oxfordian to Middle Kimmeridgian age (ox. 2–ox. 3, ki.1.–ki.1.2, ki.3, ki.1.3–ki.2.1, ki. 2.1–ki. 2.2) were used for interregional correlation. Each cycle is characterized by a vertical suite from marl to pure limestone. The bases of the marls are characterized by abundant open-marine fossils, glauconite and phosphate (fish teeth and pellets) and interpreted as condensed sections. Deepening is indicated by bioherms changing their growth form before demise from large structures into small isolated buildups, which commonly occur within deeper water. Sequence boundaries, are present at the transition from marl into limestone. Two phases (middle ki. 1.3 and ki. 1/2) of debris-flow deposition, one accompanied by the sudden spreadout of biostromes and basinward shift of bioherms, are interpreted as lowstand phases associated with sequence boundaries. The remaining sedimentary cycles described here lack such lowstand deposits. Instead, corresponding positions in the cycles are characterized by omission features. This problem is still unresolved. It may either be due to sediment trapping on the ramp or to a changing origin of the cycles compared. It is proposed here that highstand sediments, having higher contents of fine-grained siliciclastics than lowstand deposits, formed during a humid and warm climate with high rates of continued runoff and sediment transport. Lowstand deposits consist of pure offbank carbonates, because the associated drier climate reduced fluvial input of terrigenous material. Corresponding patterns of climatic change are also seen in platform sediments from the Swiss Jura Range; however, climatic cycles correlate with eustatic sea level fluctuations in only about 50% of the cases. This misfit may partially result from problems with biostratigraphic correlation (boreal— Tethyan). Small-scale sedimentary cycles with an average duration of 66’000 years (Mutabilis chron, ki. 2) to 95’000 years (Planula chron, ox. 3) provide a tool for detailed stratigraphic correlation in biostromes, small scale lenticular bioherms (1–2 m thickness) and large bedded bioherms (many tens of metres thickness). Interruptions of bioherm growth are due to temporal oxygen deficiency related to plankton blooms. The bathymetrically deepest bioherms-small and lenticular in shape—therefore suffered the highest number of ecological break-downs, whereas massive bioherms continuously remained above the critical level.