Eocene siliceous sponges from the Ebro Basin (Catalonia, Spain)

The Eocene (Bartonian) marls of the La Guixa Member and Gurb Member, Vic Marls Formation (Ebro Basin, Catalonia, Spain), contain a very rich and diversified siliceous sponge fauna. The fauna is dominated by hexactinellids; lithistids and other demosponges are rare. It consists of 16 species representing 16 genera. Eleven new species and two new genera are proposed for these sponges: Reguantella cavernosa nov. gen. nov. sp., Regadrella concinna nov. sp. (both Hexactinellida, Lyssacinosa), Eurete clava nov. sp., Pleuroguettardia iberica nov. sp., Aphrocallistes almeriae nov. sp., Hexactinella informis nov. sp. (all Hexactinellida, Hexactinosa), Brachiolites munterensis nov. sp., Centrosia viquensis nov. sp., Callicylix eocenicus nov. sp., Rhizocheton robustus nov. sp. (all Hexactinellida, Lychniscosa), Propetrosia pristina nov. gen. nov. sp. (Demospongia, Haplosclerida). Some genera of sponges in this fauna are still extant, but, in general, the predominant ones are very close in morphology, and, without doubt, closely related to the Late Cretaceous sponges. This fauna also differs considerably, in terms of composition, from most other described faunas of Tertiary sponges from the Mediterranean region, which are dominated by lithistid sponges. Lithistid sponges are rare in this investigated assemblage, which seems most similar to an as yet undescribed Eocene fauna from Italy. There is ecological differentiation in the proportions of particular sponges in various outcrops and/or stratigraphical levels that is clearly associated with water-depth-related controlling factor(s): Munter, Tona and Sta. Cecilia represent the deepest facies, Gurb is intermediate, and St. Roc and Vespella are the most shallow. The exact bathymetric position of the sponge fauna is difficult to estimate, but it seems that 100 m (but probably 200 m and more in the case of the deepest parts) of water depth may be inferred for this facies.     

‘Cambrian’ demosponges in the Ordovician of Morocco: Insights into the early evolutionary history of sponges

Cambrian spicular sponge faunas are dominated by a distinctive assemblage of demosponges and hexactinellids that are known from Burgess shale-type faunas worldwide. Most of these are previously unknown outside the Lower-Middle Cambrian (and perhaps Tremadoc) and have no obvious close relatives in later sequences. This paper describes examples of Choia sp., Pirania auraeum sp. nov. and Hamptonia christi sp. nov. from the Arenig of Morocco, associated with isolated hexactinellid spicules. A summary of the stratigraphic ranges of the major Cambrian sponge lineages is provided. These indicate an environmental contrast in the Lower Palaeozoic evolution of hexactinellids and non-lithistid demosponges, with demosponges probably undergoing cryptic diversification in nearshore environments during the Upper Ordovician.     

Upper Devonian Sponges from the Holy Cross Mountains, Central Poland

The rich fauna of Late Devonian (Late Frasnian) siliceous sponges from the Holy Cross Mountains, Poland is composed of 15 species and 11 genera. Both astylospongid demosponges (lithistids) and hexactinosan hexactinellids are present. The following new genera and/or species are proposed: D regulara Rigby and Pisera sp. nov., Jazwicella media Rigby and Pisera gen. et sp. nov., Astyloscyphia irregularia Rigby and Pisera gen. et sp. nov., A. turbinata Rigby and Pisera gen. et sp. nov., Astylotuba modica Rigby and Pisera gen. et sp. nov., Paleoregulara cupula Rigby and Pisera gen. et sp. nov., Paleoramospongia bifurcata Rigby and Pisera gen. et sp. nov., Cordiospongia conica Rigby and Pisera gen. et sp. nov., Paleocraticularia elongata Rigby and Pisera gen. et sp. nov., P gigantia Rigby and Pisera gen. et sp. nov., Polonospongiadevonica Rigby and Pisera gen. et sp. nov., P fistulata Rigby and Pisera gen. et sp. nov., Urnospongia modica Rigby and Pisera gen. et sp. nov., and Conicospongia annulata Rigby and Pisera gen. et sp. nov. The investigated fauna contains the youngest astylospongiids known and the oldest well-preserved, and most diversified Palaeozoic hexactinosans. The sponge fauna constituted a significant element of a brachiopod-coral-sponge assemblage that inhabited a deep slope of the local Dyminy Reef structure, during its final phase of growth, in a clearly hemipelagic setting. This fauna is limited to the intrashelf depression within an incipiently drowned carbonate platform.     

EXCEPTIONALLY WELL-PRESERVED MIDDLE ORDOVICIAN SPONGES FROM THE LLANDEGLEY ROCKS LAGERSTÄTTE, WALES

Abstract:  A diverse fauna of three-dimensionally preserved sponges is described from nearshore volcanogenic sandstones near Llandrindod, Mid-Wales. The fauna was preserved through early marginal silicification, in rare examples with silicification of soft tissue, and includes aspicular and spicular demosponges, hexactinellids, and a heteractinid. The fauna is largely endemic, with the following new species, genera and families erected: Onerosiconcha gregalia gen. et sp. nov., Ordinisabulo quadragintaforma gen. et sp. nov., Miritubus erinaceus gen. et sp. nov., Vadosifistula milvus gen. et sp. nov., Polycornua trescelestus gen. et sp. nov. (Pseudolanciculidae fam. nov.), P. entropus sp. nov., Palaeocallyoides improbabilis gen. et sp. nov., Reticulicymbalum tres gen. et sp. nov., Triactinella rigbyi gen. et sp. nov. (Triactinellidae, fam. nov.), Spissiparies minuta gen. nov., Brevicirrus arenaceus gen. et sp. nov., Pyritonema scopula sp. nov. (Pyritonemidae, fam. nov.) and Microastraeum tenuis gen. et sp. nov. In addition, Pseudolancicula Webby and Trotter is recorded outside Australia for the first time, although only as isolated spicules. The environment represented by this fauna has not previously yielded articulated sponges, and thus the apparent endemism may be misleading.     

The oldest bryozoans of Baltoscandia from the lowermost Floian (Ordovician) of north-western Russia: two new rare,small and simple species of Revalotrypidae

We describe two new species of esthonioporate bryozoans, Revalotrypa inopinata sp. nov. and R. yugaensis sp. nov., from the Lower Ordovician, south-east of Lake Ladoga, north-western Russia. The colonies of the two species are very small and were extracted from limestone nodules found in the lower part of glauconitic sandstone in the Joa Member (lowermost Floian). Revalotrypa inopinata sp. nov. and R. yugaensis sp. nov. are the oldest known bryozoans from Baltoscandia. Study of the two species includes scanning electron microscopy (SEM) imaging and X-ray microtomography (micro-CT). The palaeogeographic distribution of the oldest known bryozoans from the Lower Ordovician and the advantages and disadvantages of micro-CT for the study of Palaeozoic bryozoans are discussed. The authorship of Revalotrypidae, which has been inconsistently allocated in the literature, is discussed.     

ORDOVICIAN (ARENIG–CARADOC) SYNTROPHIIDINE BRACHIOPODS FROM THE EAST BALTIC REGION

Abstract:  Syntrophiidine brachiopods are a rare and poorly known component of Ordovician Baltoscandian faunas. They appear in the East Baltic in the Billingenian (lower Arenig) as part of the earliest known benthic assemblages dominated by elements of the Palaeozoic Evolutionary Fauna. These faunal assemblages usually include bryozoans, ostracodes, and the earliest known porambonitoids, strophomenides and endopunctate orthides, such as Idiostrophia and Orthidium , which later became characteristic of the Whiterockian brachiopod assemblages in Laurentia, but by that time had disappeared from Baltica. The superfamily Syntrophioidea reappears in Baltoscandia in the mid Caradoc. In contrast, Porambonitoidea remained the integral part of the Baltoscandian brachiopod associations through the Ordovician. Porambonites , herein redefined on the basis of restudy of the type species P. intermedius , includes only smooth porambonitoids; taxa with the distinctive ornament of radiating rows of pits first appeared in the group in the mid Arenig. The taxa Eoporambonites gen. nov., Tetralobula peregrina sp. nov., Idiostrophia prima sp. nov. and Idiostrophia tenuicostata sp. nov. are erected.     

A pyritized lepidocoleid machaeridian (Annelida) from the Lower Devonian Hunsrück Slate,Germany

A machaeridian, Lepidocoleus hohensteini sp. nov., is described from the Hunsrück Slate (Lower Emsian) of Germany. The available material includes a unique example preserving evidence of the soft tissues, only the second machaeridian specimen to do so and the first lepidocoleid. This specimen shows that the plates are attached to alternate segments in the trunk. The morphology is consistent with an annelid affinity of the Lepidocoleidae and confirms the unity of the Machaeridia. This discovery adds an important group to the known diversity of this famous late Palaeozoic marine Konservat-Lagerstätte.     

Peronosporomycetes (Oomycota) from a Middle Permian Permineralised Peat within the Bainmedart Coal Measures,Prince Charles Mountains,Antarctica

The fossil record of Peronosporomycetes (water moulds) is rather sparse, though their distinctive ornamentation means they are probably better reported than some true fungal groups. Here we describe a rare Palaeozoic occurrence of this group from a Guadalupian (Middle Permian) silicified peat deposit in the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica. Specimens are numerous and comprise two morphologically distinct kinds of ornamented oogonia, of which some are attached to hyphae by a septum. Combresomyces caespitosus sp. nov. consists of spherical oogonia bearing densely spaced, long, hollow, slender, conical papillae with multiple sharply pointed, strongly divergent, apical branches that commonly form a pseudoreticulate pattern under optical microscopy. The oogonia are attached to a parental hypha by a short truncated stalk with a single septum. Combresomyces rarus sp. nov. consists of spherical oogonia bearing widely spaced, hollow, broad, conical papillae that terminate in a single bifurcation producing a pair of acutely divergent sharply pointed branches. The oogonium bears a short truncate extension where it attaches to the parental hypha. We propose that similarities in oogonium shape, size, spine morphology and hyphal attachment between the Permian forms from the Prince Charles Mountains and other reported Peronosporomycetes from Devonian to Triassic strata at widely separated localities elsewhere in the world delimit an extinct but once cosmopolitan Palaeozoic to early Mesozoic branch of the peronosporomycete clade. We name this order Combresomycetales and note that it played an important role in late Palaeozoic and early Mesozoic peatland ecosystems worldwide.     

A probable hyalonematid sponge (Hexactinellida: Amphidiscophora) from the Middle Ordovician of the Builth Inlier,Wales

Modern hexactinellid sponges are diverse, but almost exclusively deep-marine organisms with a very intermittent fossil record. Aside from the fused skeletons of hexactinosan lineages (which are also exceptionally rare in Palaeozoic sediments), identifying other families is challenging due to the microscopic nature of many diagnostic characters, and the need for exceptional preservation in a deep-water palaeoenvironment. Among the more distinctive living families is the Hyalonematidae, which have several preservable diagnostic features. A new sponge (Nectocollare zakdouli n. gen. n. sp.) from the Middle Ordovician Castle Bank fauna of Wales, UK, shows several of these characters, including pinular pentactine dermalia, unbundled choanosomal diactins, and a reticulate marginal rim at the apex. No root tuft is preserved, but these are often detached from fossil sponges. Although there remains some uncertainty over the assignment to Hyalonematidae, this sponge represents the only probable example from the Palaeozoic. Even in the absence of diagnostic microscleres, it likely represents a derived, crown-group hexactinellid, and further confirms the diversification of the class during the earliest Palaeozoic.     

Echinoid Spines from the Anisian (Middle Triassic) of Qingyan, South- western China

Echinoid remains from the Triassic of China are described for the first time. The Middle Triassic of Qingyan in Guizhou Province, south-western China, has yielded nine taxa of primary spines; seven of these come from the lower Upper Anisian. Because all of the spines are disarticulated, the material is treated only parataxonomically. 'Cidaris' lineola (Bather) and 'Cidaris' wissmanni (Desor) are species originally described from the alpine Triassic of Europe. 'Cidaris' bangtoupoensis sp. nov., 'Cidaris' wachangpoensis sp. nov., 'Cidaris' venustespinosa sp. nov., 'Cidaris' fangchui sp. nov., 'Cidaris' gu sp. nov., 'Cidaris' mafengpoensis sp. nov. and 'Cidaris' sp. A are so far known only from Qingyan. Palaeoautecological interpretations based on the shapes of the spines fit well with the fact that the echinoids from Qingyan are part of highly diverse fossil associations which represent the remains of communities that lived in a protected, shallow-marine, stable soft-bottom habitat. The rather high diversity of the echinoid spines in terms of the number of both taxa and general types of shape shows that the echinoids, after nearly becoming extinct at the end of the Palaeozoic, began a new phase of adaptive radiation in the Anisian at the latest.     

Deciphering the exceptional preservation of the Early Triassic Paris Biota (Bear Lake County,Idaho, USA)

After the end-Permian mass extinction, the Early Triassic (∼251.9 to 247 Ma) is characterized by several biotic crises that particularly affected marine faunas; accordingly, marine ecosystems from this unstable interval have been often described as heavily depauperate. This assumption, however, may relate to a biased fossil record. The discovery of taphonomic windows, like Konservat-Lagerstätten, in the Early Triassic would help to better understand the composition and diversity of ecosystems at that time. The Paris Biota (Idaho, USA) is a highly diverse fossil assemblage from the earliest Spathian (early late Olenekian, ∼250.6 Ma), indicating a rapid rediversification for many groups after the end-Permian crisis and pointing toward a remarkably complex marine ecosystem ∼1.3 m.y. after the Permian-Triassic boundary. However, its detailed taphonomy has not yet been investigated. Here we present the mineral characterization of four of its most abundant taxa: discinoid and linguloid brachiopods, leptomitid sponges, and caridean shrimps. For this purpose, we combined data from Raman microspectroscopy, Fourier Transform InfraRed spectroscopy, and SEM-EDXS. Although all taxa were preserved in calcium phosphate, the morphology, structuring and size of crystals are highly dissimilar at a nano- to micrometric scale. In brachiopods, the ultrastructure of calcium phosphate shows unorganized bacillary-like crystals, while in crustaceans their size is considerably smaller and round-shaped. Similar small crystals are observed in sponges. However, the ultrastructure of calcium phosphate in sponges exhibits a well-defined preferential orientation. In addition, sponges show some compressed but preserved three-dimensional features, with an inner surface better preserved. Such analyses are essential to understand the taphonomic pathways enabling exceptional preservation. The further comprehension of preservation features would help to understand potential bias on observed diversity signals and their interpretation.     

Analysis of bacterial diversity in sponges collected off Chujado, an Island in Korea, using barcoded 454 pyrosequencing: Analysis of a distinctive sponge group containing Chloroflexi

The bacterial diversity of 14 sponges belonging to 5 different orders that were collected around Chuja Island, Korea was investigated using barcoded 454 pyrosequencing. The sponges contained many unidentified bacterial groups (e.g. more than half of the taxa at the family level) that were known only in environmental sequences and obtained from culture-independent methods. Five of the sponges were clustered into one notable group (CF group), which was distinguished from the other sponges in accordance with bacterial composition (the other sponges may be separated into more groups but clustering is not clear). The CF group contained high amounts of Chloroflexi (25.0–47.7%) and moderate amounts of Gemmatimonadetes (2.3–7.0%), AncK6 (0.6–2.2%), PAUC34f (0.8–6.0%), Acidobacteria (3.7–9.6%), and SBR1093 (1.8–5.6%) exclusively or almost exclusively to this group. Sponges in the CF group also showed higher diversity (e.g. Shannon index) than the other sponges and contained group-specific taxonomic lineages (e.g. class or family level) from group-specific phyla and even from the Proteobacteria and Actinobacteria, which were detected in all sponges at the phylum level. The CF group may be one of the most distinctive groups in sponges in terms of bacterial diversity.     

Mesozoic leaf beetles of the tribe Mesolpinini trib. nov. (Coleoptera,Chrysomelidae) from the Lower Cretaceous

This publication is based on recent studies of Lower Cretaceous leaf beetles from the Yixian Formation (Liaoning, China), which are represented by five new species of one new genus Mesolpinus gen. nov. (M. antenattus sp. nov. [type species], M. adapertilis sp. nov., M. angusticollis sp. nov., M. basicollis sp. nov., and M. trapezicollis sp. nov.) assigned to a new tribe, Mesolpinini trib. nov. of the subfamily Chrysomelinae. This tribe, which includes only species from the Jehol biota, is the oldest known group of the family in the fossil record. A key to species of the genus Mesolpinus gen. nov. is provided and the position of the new tribe is discussed. A brief overview of the Mesozoic data on the subfamily Chrysomeloidea is given.     

The origin of multiplacophorans – convergent evolution in Aculiferan molluscs

Abstract: Multiplacophorans are Palaeozoic (Silurian to Permian) stem group polyplacophorans with 17 shell plates in a particular arrangement of single terminal plates separated by three columns of plates forming five transverse rows. Their distinctive morphology has prompted disparate interpretations of their relationship to polyplacophorans. Some features are strikingly similar to crown group polyplacophorans and even to some living families. Here we describe two Devonian forms, Protobalanus spinicoronatus sp. nov., a hercolepadid from northeast Ohio, USA, and Hannestheronia australis gen. et sp. nov., a strobilepid from South Africa. Using the results from a Bayesian relaxed molecular clock to test competing scenarios of the relationship of multiplacophorans to crown group polyplacophorans, we demonstrate that multiplacophorans are stem group polyplacophorans in which certain characters of the crown group evolved convergently.     

A new diverse shark fauna from the Wordian (Middle Permian) Khuff Formation in the interior Haushi‐Huqf area,Sultanate of Oman

Abstract: Chondrichthyans are newly reported from the autochthonous Wordian Khuff Formation (middle Permian), cropping out in well‐exposed, low‐palaeolatitude sections in the interior Haushi‐Huqf area of Oman. The shark remains comprise isolated teeth, dermal denticles and fin spines and have been recovered by processing limestone in buffered acetic acid from bulk rock samples. The fauna consists of mainly ctenacanthiform and hybodontiform taxa, identified as Glikmanius cf. myachkovensis, Glikmanius culmenis sp. nov., Omanoselache hendersoni gen. et sp. nov., Omanoselache angiolinii gen. et sp. nov., cf. Omanoselache sp., Reesodus underwoodi gen et sp. nov., Teresodus amplexus gen. et sp. nov., Gunnellodus bellistriatus, Khuffia lenis gen. et sp. nov., Khuffia prolixa gen. et sp. nov. and Euselachii sp. indet. Additional specimens include rare teeth of the lonchidiid cf. ‘Palaeozoic Genus 1’ sp., of the neoselachian Cooleyella cf. fordi and a further indeterminate neoselachian, of an indeterminate petalodont and of the holocephalan Deltodus aff. mercurei and Solenodus cf. crenulatus. Fin spines add a further two taxa, Nemacanthus sp. and Amelacanthus cf. sulcatus, which have neoselachian affinities and therefore an unclear relationship to the recovered teeth. The occurrence of Nemacanthus within this Wordian fauna represents the oldest record of this taxon and its only known occurrence in the Palaeozoic. Of the remaining genera, Glikmanius has previously been recorded from the Wordian, whereas for all the others, this study represents their youngest known stratigraphic occurrence and first occurrence in Guadalupian (middle Permian) strata. This adds significantly to our knowledge of the global diversity of chondrichthyans preceding the end‐Guadalupian biotic crisis. Palaeogeographically, for all taxa, this study represents the first record from the western fringe of the marine Neotethyan basin, and only Cooleyella was previously known from the southern (Gondwanan) part of the Pangaean continental margin.     

A new sauropod dinosaur from the Lower Cretaceous Ilek Formation,Western Siberia,Russia

Sibirotitan astrosacralis nov. gen., nov. sp., is described based on isolated but possibly associated cervical and dorsal vertebrae, sacrum, and previously published pedal elements from the Lower Cretaceous (Barremian?) Ilek Formation at Shestakovo 1 locality (Kemerovo Province, Western Siberia, Russia). Some isolated sauropod teeth from the Shestakovo 1 locality are referred to the same taxon. The phylogenetic parsimony analyses place Sibirotitan astrosacralis nov. gen., nov. sp., as a non-titanosaurian somphospondyl titanosauriform. The new taxon exhibits four titanosauriform and one somphospondylan synapomorphies, and one autapomorphy – a hyposphene ridge that extends between the neural canal and the postzygapophyses. It differs from all other Somphospondyli by having only five sacral vertebrae. The new taxon shares with Euhelopus and Epachtosaurus sacral ribs that converge towards the middle of the sacrum in dorsal view. Sibirotitan astrosacralis nov. gen., nov. sp., is only the second sauropod taxon from Russia and one of the oldest titanosauriform described so far in Asia.