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Diarylamidines are a group of widely used small molecule drugs. One common use of diarylamidines is their pharmacological inhibition of ligand-gated cation channels, including tetrameric ionotropic glutamate receptors and trimeric degenerin/epithelial sodium channel/acid-sensing ion channels. Here, we discover a degenerin/epithelial sodium channel/acid-sensing ion channel from the brachiopod (lamp shell) Novocrania anomala, at which diarylamidines act as agonists. The channel is closely related to bile acid-gated, pH-gated, and peptide-gated channels but is not activated by such stimuli. We describe activation of the channel by diminazene, 40,6-diamidino-2-phenylindole, and pentamidine, examine several biophysical and pharmacological properties, and briefly explore the molecular determinants of channel activity with site-directed mutagenesis. We term this channel the diarylamidine-activated sodium channel. [ABSTRACT FROM AUTHOR]

Throughout their evolutionary history, serpulids, the calcareous tube-dwelling suspension-feeding polychaetes, formed symbiotic relationships with cnidarians (32 relationships), molluscs (six relationships), brachiopods (three relationships), bryozoans (two relationships), echinoderms (one relationship), foraminifers (one relationship) and worms (one relationship). The absolute majority of symbiotic relationships with serpulids had cnidarian partners (micropredators) in the Mesozoic and Cenozoic. There is no observed escalation in the evolution of symbiotic relationships in serpulids. There may be an optimal frequency of symbiotic relationships for serpulid fauna and when that value was achieved in the Jurassic, it stayed constant during the entire evolution of the group. However, the number of serpulid genera involved in symbiosis increased from the Jurassic (six genera) to the Cretaceous (thirteen genera). It seems that the ability to form symbiotic relationships was in general a useful trait as it spread to various branches of the serpulid phylogenetic tree. [ABSTRACT FROM AUTHOR]

The William Lake site within the Williams Member of the Stony Mountain Formation (Katian, Upper Ordovician) contains an unusual exceptionally preserved fossil fauna, including arthropods and cnidarian medusae. Several shells of the brachiopod that strongly resemble Holtedahlina paraprostrata Jin and Zhan, 2001 are described for the first time from this unit. Forty percent of the shells were found in an unusually close association with phosphatic tube-like fossils, perhaps indicating a symbiotic relationship, although there is not enough clear evidence to definitively determine the nature of this relationship. It was clearly advantageous to grow on or against skeletal material on a soft, muddy shallow marine seafloor, and both the brachiopod and the tube-like fossil may have benefited from the association at different times. Although other species of Holtedahlina have been found in a variety of depositional environments, Holtedahlina paraprostrata has thus far only been found in hypersaline or variable salinity settings, perhaps indicating an ability to tolerate unusual marine conditions, unlike most other rhynchonelliformean brachiopods that are typically stenohaline. Holtedahlina at the William Lake site, like other calcareous fossils, are rare and poorly preserved perhaps reflecting the unusual preservation at the site or representing a real ecological signal. [ABSTRACT FROM AUTHOR]

The purpose of the scientific cruise CEAMARC was to explore the East-Antarctic sector, off Georges V and Terre Adélie, to study the biodiversity of plankton, fishes and benthic fauna. The aim of the current study is to focus on a major part of this benthic fauna, highlighting the representatives of the phylum Brachiopoda. Still present in all oceans, brachiopods, suspension feeders, are not often studied. They are marine invertebrates with a calcite bivalved shell, living attached to various substrates by means of their pedicle or by cementation. The purpose of this study was to review their diversity compared to the equivalent representatives, when available, in circumpolar and/or subantarctic waters, the characteristics of the species and the micro and nanostructure of their shells (biomaterial). The ecology and depth ranges are reported. As well, the results of multiproxy assessment of the brachiopod calcite shell highlight the role these organisms play in reflecting the environmental conditions of the surrounding seawater. As highlighted in a recent study on modern shells, including some subaustral and Austral species, geochemical thermometers like carbonate clumped isotopes (Δ47), independent from δ18Osw values, were used. [ABSTRACT FROM AUTHOR]

Some taxa of belemnites, bivalves, gastropods, and brachiopods, previously unknown in the Russian Far East (except for Eastern Siberia and Northeast Russia), of both Tethyan and Boreal Arctic origin, have been recorded in the Middle Jurassic of the Soloni River (Bureya River basin). In particular, bivalve assemblages were found to increase in abundance throughout most of the Bajocian section at the Soloni River, similar to what is observed in Siberian sections. However, the first appearance of some species of the genus Grammatodon and trigoniids was recorded in this area much earlier than in Siberia. This, combined with a revision of the taxonomic composition of previously recorded fossils, has made it possible to refine the biostratigraphic subdivisions of not only the studied section, but also the uppermost Lower–Middle Jurassic marine deposits of the Bureya Trough as a whole. The age ranges of the local lithostratigraphic units have been refined to a greater degree. It has been established that the Sinkal'tu Formation corresponds to the Upper Toarcian–lowermost Lower Bajocian, the Epikan Formation to the uppermost Lower Bajocian, the El'ga Formation to the Upper Bajocian, and the Chagany Formation to the Bathonian–Callovian. Data on the palynological assemblages identified in these formations are provided. The recent studies of cephalopods and bivalves from Siberia, the Russian Far East, and southern Alaska have led to the development of a refined interregional correlation scheme for Bajocian deposits in these regions. [ABSTRACT FROM AUTHOR]

The Brădet Quarry, also known as the Bibel Quarry, occurs in Anina, Brădet area, Caraş-Severin County, South Carpathians, outcropping the highly fossiliferous, nodular limestones of the Upper Kimmeridgian - Lower Tithonian Brădet Formation. The site includes a rich and well-preserved assemblage of ammonites, belemnites, brachiopods, echinoids, bivalves and corals, next to the stratotype of the Brădet Formation, being worthy of the status of a Site of Special Scientific Interest (SSSI). [ABSTRACT FROM AUTHOR]

The crab Trapezia bidentata is a conspicuous crustacean characterized as an obligate symbiont with branching corals, such as species of Pocillopora. These crustaceans have been identified as strict corallivores with a feeding dependency on the mucus excreted by adult colonies in the genus Pocillopora. However, like other crustaceans, individuals of T. bidentata have a nutritional plasticity that has not been described. We used an integrative approach, including traditional taxonomy and high‐throughput sequencing of hypervariable region V9 of the 18S rRNA gene, to describe the mouthparts and the diet of individuals of Trapezia bidentata associated with adult colonies of Pocillopora verrucosa. The presence of setae on the ambulatory dactylus and maxillipeds, forming food brushes and combs, was evident. Sequencing and analyses of the intestinal content of the crustaceans found evidence of 18 phyla, mostly represented by Brachiopoda (28.1%), Arthropoda (31.7%), and Cnidaria (21.1%), but also small contributions (≤2%) of other animal groups such as Mollusca, Annelida, and Tunicata. In addition, a few traces (≤0.5%) of algae and fungi were identified. The feeding structures and intestinal content showed that individuals of T. bidentata are omnivorous and behave as suspension feeders and scrapers, obtaining nourishment from tissues transported in the water column and in the mucus and tissue of P. verrucosa. The results provide a clearer characterization of the role of T. bidentata, which is a crucial guard crustacean associated with P. verrucosa. We found both corallivorous and suspension‐feeding habits, which demonstrates feeding plasticity, a positive characteristic for the survival of the species. [ABSTRACT FROM AUTHOR]

Shape analysis of a large sample of the thecideid brachiopod Thecidellina from the Pliocene and Pleistocene rocks on the Caribbean island of Curaçao highlights asymmetry within the population. However, the 30 analysed specimens display a lack of a consistent asymmetry. The brachiopods were cemented to substrates by a cicatrix, accommodated by a change in shell structure. The plastic morphology of Thecidellina may have been due to overcrowding and competition for resources on limited substrates. [ABSTRACT FROM AUTHOR]

Two brachiopod species, Terebratulina tenuistriata (Leymerie, 1846) and Orthothyris pectinoides (von Koenen, 1984), have been recorded for the first time from the Middle Eocene (Late Lutetian) nummulitic limestone beds in the Darnah Formation at the Wadi Darnah area in Northeast Libya. These brachiopod species are associated here with Nummulites discorbinus (Schlotheim), Nummulites praelyelli (Boukhary and Kamal), and Nummulites bullatus (Schaub) and are widely distributed on this Middle Eocene Nummulites carbonate platform. The two recorded species are common in the Eocene rocks of Europe and the Arabian Gulf. In northern Africa, the brachiopod species Terebratulina tenuistriata (Leymerie) was only recorded from the Middle Eocene (Bartonian) of Egypt, while Orthothyris pectinoides (von Koenen) is firstly recorded from the Middle Eocene of the southern Tethyan Province (NE Libya) in the present work. [ABSTRACT FROM AUTHOR]

Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) inflammasomes are multiprotein signaling platforms that control the inflammatory response and coordinate antimicrobial defense. In the present study, the distribution of NLR, Caspase-1, and gasdermin (GSDM) homologues and their structural characteristics and evolutionary relationships were systematically analyzed in metazoa according to the genomes of species. In invertebrates, there were only NLRC and/or NLRD presented from sponge to amphioxus, and according to the evolutionary tree, NLR from sponge located in the most primitive position. Caspase-1 existed in some metazoan phyla (Brachiopoda, Ectoprocta, Arthropoda, Mollusca, Annelia, Nematoda, Platyelminthes, Coelenterate, and Porifera) and its activation sites were relatively conserved. The amino acid sequences and three-dimensional structures of N-terminal CARD/Death domain of NLR and Caspase-1 were similar in species from sponge to human. NLR and Caspase-1 co-existed in species of Brachiopoda, Mollusca, Annelia, Coelenterate, and Porifera. There was only GSDME or PJVK found in some phyla of invertebrates and their cleavage sites were conserved (DxxD). And it was predicted that the NLR inflammasome in inducing pyroptosis could occur in species of Brachiopoda, Mollusca, Annelia, and Coelenterate. These studies indicated that NLR inflammasome emerged early in sponges of metazoa, and NLR inflammasome in inducing pyroptosis first appeared in Coelenterate, suggesting that inflammasome and its mediated pyroptosis had existed in the early stage of metazoa, but they had been lost in many species during evolution. [ABSTRACT FROM AUTHOR]

A new rhynchonellide brachiopod genus and species, Skadarirhynchia semicostata gen. et sp. nov., is described from the late Pliensbachian of Livari, Rumija Mountain, southeastern Montenegro. It occurs in shallow-water brachiopod-crinoid packstone beds (bioclastic limestones) of the periplatform facies of the Dinaric Carbonate Platform. Stratigraphy is constrained by means of 87Sr/86Sr dating indicating a late Pliensbachian age, and by the fact that the brachiopod beds lie immediately below the Toarcian marly limestones, which is consistent with the regional stratigraphical position. The new species has a circular to roundly pentagonal outline and semicostate shells with 10‒12 strong angular ribs. Internally, it shows reduced dental plates, narrow and thin hinge plates inclined dorsally with small crural bases, crescent-like and laterally convex, and hamiform crura. The shell microstructure of the new taxon is characterised by a homogeneous secondary layer (a single layer with no sublayers) built of rhombic fibres that are typically of coarse-fibrous type (eurinoid pattern) 35‒50 μm wide and 20‒30 μm thick. Other co-occurring rhynchonellide species such as Prionorhynchia fraasi and Cuneirhynchia dalmasi are also described. Shell microstructures for the genus Cuneirhynchia are presented. [ABSTRACT FROM AUTHOR]

The Sr chemostratigraphic characteristics of marine sediments of the Lower Permian in the Omolon massif of Northeast Asia have been obtained for the first time based on a study of well-preserved brachiopod shells. The 87Sr/86Sr ratio in brachiopods from the Lower Permian regional horizons (regional stages) is within the following ranges: 0.70786–0.70794, Orochian; 0.70744–0.70786, Ogonerian; 0.70745–0.70748, Koargychanian; and 0.70742–0.70735, Khalalian. The obtained Sr-isotope data demonstrate good agreement with the standard variation curve of the 87Sr/86Sr ratio in the Permian Ocean. New Sr-isotope data can be used to correlate the units of the Regional Stratigraphic Scale of Northeast Russia directly with the stages of the International Permian Stratigraphic Scale. Based on recent data, the Asselian age of the Orochian regional stage of the lower part of the Permian section in the Omolon massif has been proved, and the regional correlation of the Upper Sakmarian interval established previously from biostratigraphic data has been refined. [ABSTRACT FROM AUTHOR]

Background: Wnt signaling pathways play crucial roles in animal development. They establish embryonic axes, specify cell fates, and regulate tissue morphogenesis from the early embryo to organogenesis. It is becoming increasingly recognized that these distinct developmental outcomes depend upon dynamic interactions between multiple ligands, receptors, antagonists, and other pathway modulators, consolidating the view that a combinatorial "code" controls the output of Wnt signaling. However, due to the lack of comprehensive analyses of Wnt components in several animal groups, it remains unclear if specific combinations always give rise to specific outcomes, and if these combinatorial patterns are conserved throughout evolution. Results: In this work, we investigate the combinatorial expression of Wnt signaling components during the axial patterning of the brachiopod Terebratalia transversa. We find that T. transversa has a conserved repertoire of ligands, receptors, and antagonists. These genes are expressed throughout embryogenesis but undergo significant upregulation during axial elongation. At this stage, Frizzled domains occupy broad regions across the body while Wnt domains are narrower and distributed in partially overlapping patches; antagonists are mostly restricted to the anterior end. Based on their combinatorial expression, we identify a series of unique transcriptional subregions along the anteroposterior axis that coincide with the different morphological subdivisions of the brachiopod larval body. When comparing these data across the animal phylogeny, we find that the expression of Frizzled genes is relatively conserved, whereas the expression of Wnt genes is more variable. Conclusions: Our results suggest that the differential activation of Wnt signaling pathways may play a role in regionalizing the anteroposterior axis of brachiopod larvae. More generally, our analyses suggest that changes in the receptor context of Wnt ligands may act as a mechanism for the evolution and diversification of the metazoan body axis. [ABSTRACT FROM AUTHOR]

We combine published and new mineralogical data on most major taxa of brachiopods from all over the world, to investigate patterns and controls on brachiopod carbonate mineralogy. Measurements of 1726 specimens in 162 species (including 56 fossil species) ranged from 79°N to 74°S and from intertidal to almost 4000 m deep. Calcareous brachiopods mostly create strong resilient valves of very low-Mg calcite ($\bar{\chi }$ χ ¯ = 1.3 wt% MgCO3). The substrate-cemented Craniida ($\bar{\chi }$ χ ¯ = 8.9 wt% MgCO3) and Thecideida ($\bar{\chi }$ χ ¯ = 6.5 wt% MgCO3) are unusual in precipitating calcite with higher Mg content. This is the first study to find bimineralic brachiopods; a few species show a combination of low-Mg ($\bar{\chi }$ χ ¯ = 0.8 wt% MgCO3) and intermediate-Mg calcite ($\bar{\chi }$ χ ¯ = 7.2 wt% MgCO3) (sensu Smith AM, Key MM Jr, Gordon DP. 2006. Skeletal mineralogy of bryozoans: taxonomic and temporal patterns. Earth-Science Reviews. 78:287–306.). While Mg in calcite varies systematically among valve layers and sometimes along the growth axis, we found no consistent difference between valves of the same individual. A weak latitudinal signal indicates some overall temperature control of Mg, but in general, brachiopods are active calcifiers, precipitating low-Mg calcite even when Mg:Ca ratio in seawater is high. The drivers on brachiopod mineralogy are individual, environmental, and phylogenetic – resulting in complex variability. [ABSTRACT FROM AUTHOR]

As the first major biotic event in the Phanerozoic, the two‐phased Late Ordovician mass extinction (LOME) resulted in a substantial decline in marine benthic biodiversity and heralding shifts in palaeobiogeography. However, the interplay between palaeobiogeographical distribution and biodiversity dynamics during this event remains unknown. Drawing upon brachiopod occurrence data from five intervals pre‐ and post‐LOME, extracted from the Paleobiology Database, we conducted a comprehensive analysis of palaeogeographic units across the extinction event. Through examination of generic diversity, origination and extinction rates, and biogeographic connectedness, we elucidate the evolutionary trajectories of both endemic and cosmopolitan taxa throughout the extinction. Our findings indicate increased vulnerability of endemic taxa to biotic events and their aftermath relative to their cosmopolitan counterparts. Notably, we observe a concordance between shifts in the palaeogeographic distribution of brachiopods and fluctuations in their diversity during and after the LOME. Moreover, the extinction and subsequent recovery dynamics of brachiopods during this event demonstrate temporal symmetry concerning biodiversity change and palaeobiogeographic structural shifts. Shortly after the extinction event, within a timeframe similar to the decline in diversity and contraction of palaeogeographic distribution, both aspects revert to pre‐extinction levels, suggesting the limited intensity of the LOME event. [ABSTRACT FROM AUTHOR]

In paleobiology and macroevolution research, the spatial aggregation of fossil data can be influenced by the modifiable areal unit problem (MAUP), wherein the selection of different grid-cell sizes for data aggregation can lead to variations in statistical results. This study presents a case analysis focused on the spatial extent of marine bivalves and brachiopods over time across three Areas of Interest (AOIs) to evaluate the potential impact of the MAUP in grid-based fossil data processing. By employing rectangular grid matrices with cell sizes of 50, 100, 200, and 400 km, this research assesses the MAUP-related sensitivity of two commonly used grid-based proxies for species' spatial distribution. The results reveal that the proxy based on the number of occupied grid cells (OGCs) is particularly sensitive to changes in cell size, whereas the proxy based on minimum-spanning-tree distance (MST distance) demonstrates greater robustness across varying grid scales. This study underscores that when constructing proxies for species' spatial distribution ranges using grid matrices, the OGC method is more susceptible to MAUP effects than the MST distance method, warranting increased caution in studies employing the OGC approach. [ABSTRACT FROM AUTHOR]

The encrusted bivalve steinkerns in the Upper Ordovician of Estonia suggest that the rapid sea-floor cementation facilitated the early lithification of the sediment within the bivalve shell and the shell valves, likely aragonitic in composition, were dissolved due to calcite sea conditions similarly to many other regions in the Ordovician. The abandoned bivalve shells contained cryptic invertebrates. The coelobite fauna was dominated by encrusting brachiopods, followed by bryozoans and cornulitids. The bryozoans and cornulitids do not prefer specific regions of the shell interior, indicating that the waters within the shell were sufficiently nutrient-rich throughout. Encrusting brachiopods are always confined to valve margins, suggesting that the waters were nutrient-rich enough for the brachiopods only at the edge of the outer environment. Thus, it is possible that bryozoans and cornulitids were better adapted for a cryptic life than the encrusting brachiopods in the Late Ordovician of Estonia. [ABSTRACT FROM AUTHOR]

The brachiopods are sessile invertebrates with an unusual blood system, which consists of a long‐branched dorsal vessel. It is still unknown how blood circulates in this system. In the present study, for the first time we propose the circulation of blood in brachiopod Hemithiris psittacea based on morphological and experimental data. The main heart is located on the dorsal side of the stomach and divides the dorsal vessel into anterior and posterior parts. The anterior part enters the lophophore, where it gives off blind branches to each tentacle. The posterior part passes by the funnels of the nephridia and forms a blindly closed network in the gonads. We suggest that the circulation of blood includes three successive stages. During the first phase of systole of the main heart, blood flows through the anterior dorsal vessel. During the second phase of systole, blood flows through the posterior dorsal vessel. During diastole, blood flows from the anterior and posterior vessels and fills the main heart. The origin of a peculiar blood system in brachiopods can be explained by reduction of the ventral vessel, which is probably correlates with the reduction of the ventral side of the brachiopod ancestor's body. Another peculiarity of brachiopod blood system is the presence of an ampullar heart, which functions as a blood depot and allows blood to move in the vessels in two directions in an oscillatory mode. The brachiopod blood system contains vessels lacking true endothelium and can be classified as an "incompletely closed" type. Research Highlights: The blood system of brachiopods contains a dorsal vessel divided into anterior and posterior parts. Circulation includes three stages: during the first phase of systole, blood flows in the anterior vessel, during the second phase of systole, blood flows in the posterior vessel, and during diastole, blood flows from the anterior and posterior vessels and fills the main heart. [ABSTRACT FROM AUTHOR]

Mollusks encompass enormous disparity, including familiar clams and snails alongside less familiar aculiferans (chitons and vermiform aplacophorans) with complex multicomponent skeletons. Paleozoic fossils trace crown mollusks to forms exhibiting a combination of biomineralized shells and sclerites (e.g., scales, spines, and spicules). We describe a shell-less, Cambrian stem mollusk, Shishania aculeata gen. et sp. nov., with conical, hollow chitinous sclerites and a smooth girdle, broad foot, and mantle cavity. The sclerites have a microstructure of narrow canals consistent with the impressions of chaetal microvilli found in annelids and brachiopods. Shishania sclerites provide a morphological stepping stone between typical chaetae (chitinous bristles) and the external organic part of aculiferan sclerites that encloses a mineralized body. This discovery reinforces a common origin of lophotrochozoan chaetae and the biomineralized aculiferan sclerites, suggesting that the mollusk ancestor was densely covered with hollow chitinous chaetae. [ABSTRACT FROM AUTHOR]

Brachiopod-rich accumulations of the well-known 'VilserKalk' calcareous units from the Middle Jurassic of Zehrer (Allgäuer Alps) have been recognised and analysed from a taphonomic standpoint. These brachiopod concentrations are frequent in the Jurassic deposits of various Alpine-Mediterranean localities, usually related to resedimentation processes generated by high-hydrodynamic episodes. In the four brachiopod-bearing accumulations recorded, high concentrations of mainly articulate shells are preserved in pocket-like deposits made up of brachiopod communities with quite different structure, size-frequency distribution, diversity and taxonomic composition. The analysed taphocharacters indicate different hydrodynamic regimes of diverse intensity for each accumulation, resulting in a gradation of the resedimentation processes. The inferred transport of the shells from the source area is minimal, the bioclastic levels constituting para-autochthonous assemblages without significant spatial averaging. The four defined taphofacies include different assemblages that chronostratigraphycally span the latest Toarcian-early Bajocian interval. These taphofacies are interpreted in terms of depth-related variations concurring with environmental disturbance events in several phases of the evolutionary history of the basin, progressively ranging from shallower proximal accumulations to shell-beds originated in more distal depositional environments. [ABSTRACT FROM AUTHOR]

The species Orbirhynchia mantilliana is newly documented in Algeria, identified within the Upper Campanian marly limestone of the Akhdar Member in the Abiod Formation at Djabel Gueroun, Batna Province, Aurès Basin. It is associated with Upper Campanian faunal markers such as the ammonite species Nostoceras (Bostrychoceras) polyplocum, found within the planktic foraminifera Globotruncana calcarata Zone. The O. mantilliana displays a restricted geographic distribution and biogeographic range, confined to Algeria, the United Kingdom, and Germany. [ABSTRACT FROM AUTHOR]

The evolution of brachiopod symbiosis is closely tied to the evolution of brachiopod faunas and their partner groups during the early Palaeozoic. Brachiopod groups with a larger number of taxa had more symbiotic associations, and there was no specific group that was more prone to symbiosis during this time interval. The first symbiotic associations appeared soon after the emergence of certain brachiopod groups, with Cambrian brachiopods partnering with typical representatives of the Cambrian fauna. Bryozoans and tentaculitoid tubeworms, which became important partners during the Ordovician and Silurian, first diversified in the Ordovician. The gradual decrease in the number of brachiopod partner groups from the Cambrian to the Silurian was likely due to specialisation. However, the number of symbiotic associations did not increase faster than the number of brachiopod taxa. The GOBE-induced diversification of brachiopod taxa did not lead to an escalation in symbiotic relationships. Symbiotic associations involving brachiopods continued after the end-Ordovician mass extinction. Although early Palaeozoic brachiopods were vulnerable to kleptoparasites, the harm caused by these parasites was not enough to drive their associated brachiopods to extinction. [ABSTRACT FROM AUTHOR]

The current biodiversity of 14 phyla, namely Platyhelminthes, Xenacoelomorpha, Nematoda, Acanthocephala, Brachiopoda, Kinorhyncha, Nemertea, Chaetognatha, Tardigrada, Gastrotricha, Rotifera, Phoronida, Echinodermata, and Chordata (invertebrates only, including the subphyla Tunicata, Cephalochordata, and Hemichordata) from the coasts of Türkiye is revisited. It was found that a total number of 695 species occur along all the coastlines of Türkiye, with the Black Sea being represented by 297 species, the Sea of Marmara by 305 species, the Aegean Sea by 308 species, and the Levantine Sea by 204 species. The most species-rich phyla in these regions were Platyhelminthes (249 species), Nematoda (131), Echinodermata (98), and Chordata (85). A total of 26 alien species have been reported from the regions to date, of which one species belongs to Chaetognatha, 8 species to Echinodermata, and 17 species to Tunicata. The highest number of alien species (17) was encountered in the Levantine Sea and the lowest (2) was in the Black Sea. [ABSTRACT FROM AUTHOR]

The discinid brachiopod from the Lower Triassic Osawa Formation in the Southern Kitakami Terrane, Japan, exhibited a unique morphological combination of a narrow pedicle track (listrium) and a V-shaped large depressed area, thereby suggesting an intermediate form between the Palaeozoic Orbiculoidea and the extant Discinisca. Based on these characteristics, we propose Bronzoria recta gen. et sp. nov., a genus that appeared in the late Permian and was widely distributed during the Triassic period. Morphological analysis of extant discinids revealed that the pedicle area showed an arrowhead-shaped median plate and a pair of semilunar plates, equivalent to the inner and outer listrial plates of Palaeozoic-type discinids, respectively. Consequently, there are great differences in the development of the pedicle area, i.e., the large pedicle area of extant discinids is suitable for robust pedicle attachment, whereas the narrow pedicle area of Bronzoria gen. nov. suggests a free-lying mode of life. Given the relationship between pedicle-related structures and the mode of life, we hypothesised that the evolution of the large depressed area preceded the development of the pedicle area. Subsequently, the large depressed area accommodated a larger pedicle, facilitating an autecological innovation for pedicle attachment, as observed in extant species. [ABSTRACT FROM AUTHOR]

Bioclaustrations are among the best ways that parasitic associations are preserved. A new bioclaustration, Haplorygma productidophilia csp. nov., is here described from the ventral interior of the Carboniferous productid brachiopod Eomarginifera lobata. The location and morphology of the structures in the ventral valve differ from the structure in the dorsal valve, suggesting that two different organisms infested the shells of Eomarginifera lobata. It is possible that whether it was ventral or dorsal valve was an important selection criterion for the infesting organisms, which were likely parasites. The proportion of infested productids was low in the population (5.8%). This low infestation rate could indicate that productids had effective methods for resisting parasites, or that the parasites were ineffective in spreading through the brachiopod population. [ABSTRACT FROM AUTHOR]

The discinid brachiopod from the Lower Triassic Osawa Formation in the Southern Kitakami Terrane, Japan, exhibited a unique morphological combination of a narrow pedicle track (listrium) and a V-shaped large depressed area, thereby suggesting an intermediate form between the Palaeozoic Orbiculoidea and the extant Discinisca. Based on these characteristics, we propose Bronzoria recta gen. et sp. nov., a genus that appeared in the late Permian and was widely distributed during the Triassic period. Morphological analysis of extant discinids revealed that the pedicle area showed an arrowhead-shaped median plate and a pair of semilunar plates, equivalent to the inner and outer listrial plates of Palaeozoic-type discinids, respectively. Consequently, there are great differences in the development of the pedicle area, i.e., the large pedicle area of extant discinids is suitable for robust pedicle attachment, whereas the narrow pedicle area of Bronzoria gen. nov. suggests a free-lying mode of life. Given the relationship between pedicle-related structures and the mode of life, we hypothesised that the evolution of the large depressed area preceded the development of the pedicle area. Subsequently, the large depressed area accommodated a larger pedicle, facilitating an autecological innovation for pedicle attachment, as observed in extant species. [ABSTRACT FROM AUTHOR]

Bioclaustrations are among the best ways that parasitic associations are preserved. A new bioclaustration, Haplorygma productidophilia csp. nov., is here described from the ventral interior of the Carboniferous productid brachiopod Eomarginifera lobata. The location and morphology of the structures in the ventral valve differ from the structure in the dorsal valve, suggesting that two different organisms infested the shells of Eomarginifera lobata. It is possible that whether it was ventral or dorsal valve was an important selection criterion for the infesting organisms, which were likely parasites. The proportion of infested productids was low in the population (5.8%). This low infestation rate could indicate that productids had effective methods for resisting parasites, or that the parasites were ineffective in spreading through the brachiopod population. [ABSTRACT FROM AUTHOR]

This paper presents a description of the Olenekian–Anisian sections in South Primorye, Far East Russia, containing reptile remains. The paper describes important ammonoid Flexoptychites cf. rifunus (Yabe et Shimizu), as well as Flexoptychites cf. compressus (Yabe et Shimizu), which are stratigraphically significant. New Anisian reptile remains were discovered from four stratigraphic levels in South Primorye: (1) the upper part of the middle Anisian Acrochordiceraskiparisovae Zone (Ichthyopterigia indet. A), (2) the middle part of the upper Anisian Flexoptychites cf. rifunus Beds (Reptilia indet. cf. Ichthyopterygia A), (3) the upper part of the upper Anisian Flexoptychites cf. rifunus Beds (Ichthyoterygia indet. B), and (4) the uppermost part of the upper Anisian Flexoptychites cf. rifunus Beds (Reptilia indet. cf. Ichthyopterygia B). The Anisian stage is marked by an abundance of medium- to large-sized ichthyopterygians and a comparatively limited number of gigantic forms, particularly in the eastern Panthalassic and western Tethyan provinces. Our recent discovery has unveiled the presence of medium- to large-sized reptiles, seemingly ichthyopterygians, in the western Panthalassic province during the late Anisian (Flexoptychites cf. rifunus Chrone). [ABSTRACT FROM AUTHOR]

The late Famennian Sarcheshmeh Member of the Khoshyeilagh Formation contains a sizeable rhynchonellide component comprised of eight genera and ten species, including Golestanirhynchus golestanicus sp. nov. Petasmaria sartenaeri sp. nov. Tilabadirhynchus azadshahrensis gen. et sp. nov. Tilabadirhynchus qeshlaqensis gen. et sp. nov. and Megalopterorhynchus chanakchiensis giganteus subsp. nov. The characters of brachiopod biostratigraphical distribution in the Sarcheshmeh Member and correlation with conodont biozonation suggest that Megalopterorhynchus chanakchiensis giganteus does not cross the lower boundary of the Bispathodus ultimus Zone, while Araratella anatolica is probably confined to it. The pugnacoidean genus Petasmaria is reported for the first time outside of North America. The broad paleobiogeographic affinities of the late Fammenian rhynchonellide assemblages from the Sarcheshmeh Member of the Alborz Region with the contemporaneous brachiopod faunas of Central Iran, Afghanistan and Transcaucasia corroborate the well-established pattern of increasing cosmopolitanism of the brachiopod faunas towards the end of the Devonian Period. [ABSTRACT FROM AUTHOR]

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell structures is the organo-phosphatic cylindrical column exclusive to phosphatic-shelled brachiopods, including both crown and stem groups. However, the complexity, diversity, and biomineralization processes of these microscopic columns are far from clear in brachiopod ancestors. Here, exquisitely well-preserved columnar shell ultrastructures are reported for the first time in the earliest eoobolids Latusobolus xiaoyangbaensis gen. et sp. nov. and Eoobolus acutulus sp. nov. from the Cambrian Series 2 Shuijingtuo Formation of South China. The hierarchical shell architectures, epithelial cell moulds, and the shape and size of cylindrical columns are scrutinised in these new species. Their calcium phosphate-based biomineralized shells are mainly composed of stacked sandwich columnar units. The secretion and construction of the stacked sandwich model of columnar architecture, which played a significant role in the evolution of linguliforms, is highly biologically controlled and organic-matrix mediated. Furthermore, a continuous transformation of anatomic features resulting from the growth of diverse columnar shells is revealed between Eoobolidae, Lingulellotretidae, and Acrotretida, shedding new light on the evolutionary growth and adaptive innovation of biomineralized columnar architecture among early phosphatic-shelled brachiopods during the Cambrian explosion. [ABSTRACT FROM AUTHOR]

An upper Pliensbachian–Aalenian brachiopod succession is reported from Ponor Mountain, Western Balkan Mountains, Bulgaria. This includes nine species (6 rhynchonellides and 3 terebratulides) from eight genera. A new genus Bulgariarhynchia and two new species, Bulgariarhynchia ponorensis and Capillirhynchia brezenensis, are formally described. A single species Homoeorhynchia ? aff. prona was found in the upper Pliensbachian. Most of the brachiopods derived from the Toarcian–Aalenian interval, and comprise: Pseudogibbirhynchia jurensis, Rhynchonelloidea angulata, Globirhynchia subobsoleta, Sphaeroidothyris uretae, Lobothyris? hispanica, and Telothyris jauberti. The brachiopod assemblages were dated using coeval ammonite biostratigraphy. Both ammonites and brachiopods display clear northwest European affinities. The new brachiopod taxa are considered autochthonous for the Balkan Mountains. Three biofacies (BF2, BF3 and BF5) were recognised and implied alternating suboxic to anoxic bottom water conditions. A few geochemical proxies are indicative of the early Toarcian Oceanic Anoxic Event (T-OAE) in the stratigraphic column. The main T-OAE pulse was fixed at the coeval positive δ13C and negative δ18O excursions, as well as increases in Hg/TOC ratios and redox-sensitive elements. The late Pliensbachian–earliest Toarcian time span was found to be the most hostile for the brachiopods. Above it, brachiopods lived in less stagnant environments. [ABSTRACT FROM AUTHOR]

The Ordovician wave-dominated sandstones of the Daoura (Ougarta range, NW Algeria) contain shell beds with cornulitids in an exceptional state of preservation. The objective of this study, focused on the sandstone of the uppermost part of the Hassi Chaamba Fm. (Sandbian?), is to understand the shell beds from the hydrodynamic and stratigraphic perspective with the combined approach of facies sedimentology and taphonomy. A 40-m section encompassing the shell beds was studied in detail. The shell beds are preserved as dm-scale concentrations in transgressive deposits of 5 high-frequency sequences preserved at the turnaround from a regressive to a transgressive sequence set. The biota in shell beds are dominated by brachiopods, cornulitids and gastropods, suggesting that the related ecosystem extended to the offshore. Three types of shell beds are distinguished, ranging from a conglomerate in the foreshore to a hardground in the offshore transition. In the lower shoreface, the shell beds are interstratified with fine-sand SCS infilling large-scale (up to 20m in wavelength) troughs eroded in the foreshore by transgressive ravinement. The petrographic and tomographic analysis of a sample of these shell beds shows that cornulitids and, to a lesser extent, brachiopods of the shell beds are perfectly preserved within a matrix composed of bioclasts. This suggests that they were reworked from nearby areas and therefore were present in the foreshore. Aggregation of cornulitids in clusters of 4–5 individuals suggests an adaptation to loose grounds in a relatively high energy setting. The rhythmic alternation of shell beds and sandstones in these deposits suggests a possible role of tides in their formation. [ABSTRACT FROM AUTHOR]

In this study, the first trimerellide brachiopods from Estonia are described. They occur in the uppermost Katian (Upper Ordovician) shallow shelf environments and represent some of the largest Ordovician brachiopods. The trimerellides described are assigned to the genus Gasconsia Northrop, 1939, which disappears before the Hirnantian and reappears in the lowermost Wenlock after a long interregnum. In the Baltic Basin, the new data from Estonia expand the distribution area of Gasconsia from the Scandinavian facies belt in the west to the Estonian shallow shelf in the east. Despite poor preservation, the specimens studied revealed some structures in shell morphology important for species level identification. The strati - graphic position of Gasconsia is analyzed relative to the Katian-Hirnantian (Pirgu-Porkuni regional stages) boundary and the occurrence of the late Katian brachiopod Holorhynchus in Estonia. The improved data on the distribution of Gasconsia in time and space and a short discussion on brachiopod gigantism are presented. [ABSTRACT FROM AUTHOR]

The correlation of the Coniacian and Santonian chalks of the Anglo-Paris Basin is described on the basis of detailed lithological logs and extensive records of macrofossils and microcrinoids. In the almost complete absence of ammonites, inoceramid bivalves afford the highest resolution correlation of these stages in chalks, but their value here is limited by the absence of key genera and species, most notably in the Upper Coniacian and middle and Upper Santonian. Echinoids and other macrofossils (brachiopods, stalked crinoids, belemnites) have proved useful, but many are long-ranging or uncommon. Some marker beds, including flints and marl seams, provide useful correlations across the basin, but are locally absent. For the Upper Santonian, the stemless benthonic crinoids Uintacrinus and Marsupites provide high-resolution correlation, both within the basin and to other regions. The successions on the basin margins, in the far north of France (Nord, Pas de Calais) and the southwest (Touraine) are condensed and yield ammonites in association with important inoceramid species. The controls on sedimentation caused by sea-level changes are evaluated on a basinal and global scale, most especially for the Upper Santonian. [ABSTRACT FROM AUTHOR]

The serpulid tube worm Laqueoserpula reussi (Weinzettl, 1910), originally introduced as a gastropod named Burtinella(?) reussi, is described from the Upper Cenomanian and Lower Turonian of the Bohemian Cretaceous Basin. It had usually been confused with other species and genera before 2008. Comparison with specimens from the type locality of the type species of the genus Laqueoserpula Lommerzheim, 1979 confirms the affiliation of the Bohemian species to this genus. The simple prismatic (SP) ultrastructure of the tube wall of L. reussi agrees with an assignment to the tribe Serpulini Rafinesque, 1815. In the Upper Cretaceous, representatives of Laqueoserpula are exclusively found in nearshore deposits, where they are accompanied by a high diverse marine invertebrate fauna. By its compact, large and robust tube forming a spiral and extremely thick tube wall, L. reussi was well-adapted to live in nearshore high energy environments, where its tube could be encrusted by bryozoans, brachiopods and oysters, and infested by hydroids and borers. [ABSTRACT FROM AUTHOR]

The asymmetry observed in rhynchonellid brachiopod shells has been discussed for decades and continues to attract attention. This noteworthy modification of the anterior margin morphology during the ontogeny has evolved several times in rhynchonellids, and seems to reflect a genetic basis. First, we try to clarify the terminology regarding asymmetrical, dissymmetrical and symmetrical shells that has existed since the beginning of the 20th century. The Cretaceous populations observed clearly exhibit antisymmetry (also called random asymmetry). During the Cretaceous, some populations of Cyclothyris McKoy, 1844 include a mixture of truly asymmetrical specimens and others that exhibit an intermediate degree of asymmetry, herein called atypical morphologies. Shapes of specimens coming from two different locations in France were captured using geometric morphometrics. We used the range of different morphologies: 1) to test alternative hypotheses about the ontogeny of asymmetry; 2) to test for the possibility of several morphogroups; and 3) to discuss the determinism of the asymmetry. [ABSTRACT FROM AUTHOR]

Brachiopods from the upper part of the Khalpirkian Regional Stage of the Tiryakh–Kobyume section of the Kobyume structural–facies zone in Southern Verkhoyanie have been studied. The collection is dominated by Strophalosia? vollossovitschi (Fredericks) and Cancrinella? sp. Single spiriferids are assigned to Crassispirifer monumentalis Abramov et Grigorjeva and Cr. aff. monumentalis Abramov et Grigorjeva, and, thus, host deposits are referred to the Crassispirifer monumentalis Beds. We found these beds earlier only in the lower part of the Khalpirkian Regional Stage. Reliable findings of the terminal brachiopod assemblage confined to the Khalpirkian of the Upper Permian have been reviewed. The assemblage is dominated by strophalosiids represented by Wyndhamia gijigensis (Zavodowsky), Marginalosia? magna Abramov et Grigorjeva, Subtaeniothaerus lungersgauzeni Solomina, and Strophalosia? aff. vollossovitschi (Fredericks). "Magadania" sp. and Cancrinella? sp. have been identified from linoproductids. Crassispirifer monumentalis spiriferids are an important element of the terminal assemblage. Athyridids of the Khalpirkian Regional Stage, known only in its lower part, are represented by Cleiothyridina nikolaevi Grunt, Cleiothyridina sp., and Bajtugania sp. The studied regional stage also contains findings of terebratulids attributed to Marinurnula? aff. mantuanensis (Campbell) and M.? aff. chivatschense (Zavodowsky). No brachiopods are known at the top of the Khalpirkian Regional Stage, while rhynchonellids Piarorhynchia sp. appear at the base of the Nekuchan Regional Stage. At the beginning of the Khalpirkian, the brachiopod community had an extended natural habitat in the shelf zone of the Verkhoyan Sea along the Angaraland coastline. Subsequently, this area was reduced and initially divided into two independent subareas confined to the East Kharaulakh and South Verkhoyan sectors. In the Late Khalpirkian, the brachiopod community was concentrated only in the Kobyume zone, where it ended up under the end-Permian mass extinction. Some taxa of the identified brachiopod assemblage have been traced in the Okhotsk region, the Ayan—Yuryakh anticlinorium, and the Omolon massif. [ABSTRACT FROM AUTHOR]

The articulate brachiopod Terebratulina chrysalis is very common in the Upper Cretaceous chalk of northern Europe and in the Danian chalk, bryozoan limestone and coralline-bryozoan limestone mounds of Denmark. It was one of the few brachiopod species that survived the mass extinction at the Cretaceous--Palaeogene boundary and it belongs to a long-lived group of closely related Cretaceous--Recent species. It represents a non-specialised generalist which with a rootlike pedicle was able to attach itself to a great variety of both hard and soft substrates. The great adaptability is probably the main reason for its evolutionary success. This is the first systematic study concerning brachiopods from the Kerteminde Marl Formation in Denmark. Hitherto Terebratulina chrysalis is the only known brachiopod from the Gundstrup blocks, referred to the Kerteminde Marl. [ABSTRACT FROM AUTHOR]

Eucalathis, a member of the brachiopod superfamily Cancellothyridoidea, is common in Recent seas. The 15 known species have an almost cosmopolitan distribution, but no known occurrence in the Mediterranean Sea. Despite the rich Recent record, very little is known about the geological history of Eucalathis. In the Mediterranean, two fossil species are known from the Miocene of Italy. Two additional Eucalathis species from the Neogene of Italy are identified: E. davidi sp. nov. from NW Italy (Marmorito, Early Pliocene), and E. dorae sp. nov. from Sicily (Altavilla, Late Pliocene). It proves that Eucalathis did not disappear from the Mediterranean after the Messinian Salinity Crisis. Based on the four known species, Eucalathis (probably apart from the Messinian Crisis) was present in the Mediterranean from the Middle Miocene to the Late Pliocene. Its disappearance is possibly related to the Pleistocene cooling. Currently, three species of Eucalathis occur in the NE Atlantic, near the entrance to the Mediterranean. However, they are unable to enter because the distribution of all three species is restricted to deeper environments than the average 300 m deep Gibraltar sill. The circulation pattern of the Gibraltar area also prevents deeper water Atlantic species from entering the Mediterranean. [ABSTRACT FROM AUTHOR]

Problems Statement and Purpose. The colouration (when pigment is distributed more or less uniformly within skeletal substance) and colour patterns (when pigment is concentrated or arranged in bands, lines, spots, patches, etc.) of fossil brachiopod shells is poorly understood, since its preservation in the fossil record requires the coincidence of several, sometimes random, taphonomic factors. However, the study of the original colouration of fossil invertebrates is of great palaeoecological and taphonomic importance (e.g., to study of the evolution of vision, the development of predator-prey relationships). Records of Palaeozoic brachiopod shells with preserved colouration are quite rare and the shell colouration and colour patterns are currently known for only 15 genera. Data and Methods. Studied isolated valves of the lingulid brachiopods Lingularia mytiloides from the lower Moscovian Kamensk Formation of Luhansk Region (Ukraine) show a preserved colour pattern on the outer surface, represented mainly by light concentric bands. Studied remains are represented by small, 8-10 mm long and 6-7 mm wide, moderately convex ventral thinshelled valves with elongate elliptical outlines, a rounded anterior margin, subparallel lateral margins and a small, pointed umbo. Valve surface is covered with thin concentric growth lines and weakly developed rugae. Results and Discussion. The studied specimens were divided into two groups based on shell colouration features, which may reflect some details of the colouration and colour patterns. However, these differences may be taphonomic artefacts. It is quite possible that the colour bands on the surface of the valves are evidence of sulphide oxidation, but even so, they likely still reflect the original colour patterns. Environmental conditions were important factors for the preservation of the colouration on the shells of the studied lingulid brachiopods. Among these conditions, the most important were slow sedimentation, absence of agents of mechanical and chemical destruction, such as high-energy water activity, encrustation by epibionts, etc., dysaerobic conditions, and rapid burial apparently accompanied by the activity of bacterial communities. The studied colour patterns on the shells of Lingularia mytiloides are similar to those on other fossil lingulids. The adaptive significance of this colouration for the studied lingulids, which lived infaunally, remains unclear and cannot be resolved with the available material. [ABSTRACT FROM AUTHOR]

Lingulate brachiopods are described from the mid-Sheinwoodian "Miraspis" Limestone in the famous LoděniceŠpičatý vrch locality near Loděnice in the Barrandian area. Twenty-three species have been determined, some only identified to generic or family rank due to rarity or poor preservation. Two new genera Platylops (Subfamily Elliptoglossinae) and Praethele (Family Orbiculoideidae) and three new species are described: Schizotreta elegantia sp. nov., Praethele postvexata sp. nov., and Orbaspina involuta sp. nov. Several poorly known species erected by Joachim Barrande in l879 are redescribed and their taxonomic rank and stratigraphic occurrences are elucidated. Species assigned to genera Pseudolingula, Barrandeoglossa, Kacakiella, Wadiglosella, Lingulops, Schizocrania, Schizobolus, Acrosaccus, Sterbinella, Artiotreta, Acrotretella, Havlicekion and Opsiconidion are described. The brachiopods come from sediments where Cooksonia barrandei and other earliest land plants have been observed. The unexpectedly high taxonomic diversity indicates a favourable marine environment in the surroundings of a volcanic island(s). The common presence of the widespread acrotretid brachiopods and small but remarkably diverse discinid brachiopods corroborate the dominance of the epibenthic or epiphytic life habit of lingulates over the burrowing style of the pedunculate forms. • Key words: Sheinwoodian, Silurian, organophosphatic brachiopods, Barrandian. [ABSTRACT FROM AUTHOR]

The brachiopod species Dalmanella kegelensis Alichova, 1953 is reported in the geological literature of the Baltic region as a species characteristic of the Keila Regional Stage at the Sandbian--Katian transition, and a nominal taxon of a regional biozone. The spatial dis tribution of D. kegelensis forms a belt around the deeper parts of the palaeobasin. The east ernmost occurrences of D. kegelensis have been recorded at the westernmost periphery of the Moscow Basin. The selection of the holotype of the species D. kegelensis from a locality in western Estonia caused some confusion in understanding Alichova's species, since the description of the species is mainly based on brachiopods collected from northwestern Russia. The earlier attempt to revise the taxonomy of D. kegelensis group brachiopods was unsustainable, while assigning these brachiopods to the genus Horderleyella is no longer feasible. However, two subspecies were identified, which are discussed here as two separate species, kegelensis and oanduensis, belonging to two different genera: one species belongs to the new genus Alichovella in the family Draboviidae, and the second one, following Alichova's classification, to the genus Dalmanella in the family Dalmanellidae. These species possibly represent somewhat different ages prior to the beginning of the Guttenberg carbon isotope excursion and supposedly differ in their positions on the onshore-offshore transect. [ABSTRACT FROM AUTHOR]

Introduction: The Sierra Santa Teresa is located 20 km southeast of Hermosillo in the central region of Sonora state, Mexico. The sedimentary strata mainly correspond to limestone, mudstone, wackestone and packstone texture, from the upper Paleozoic. The biota is represented by crinoids of the morphospecies Baryschyr anosus, Cyclocaudex insaturatus, Floricyclus angustimargo, Cyclocion distictus, Lamprosterigma erathense, Preptopremnum rugosum in association with algae, fusulinid foraminifera, coralline sponges (Chaetetes sp.), solitary corals (Lophophyllidium sp., Fomichevella sp.), fenestellid bryozoans (Archimedes stoyanowi), and brachiopods (Antiquatonia sp.). Objective: The principal aim of this study is to analyze the biotic composition in the Sierra Santa Teresa and its paleoecological and paleogeographical considerations. Methods: In this study we synthetize information about the principal taxa collected in outcrops of the Carboniferous of the Sierra, Santa Teresa. Results: The distribution of the biota, and particularly the crinoid morphospecies, allowed paleobiogeographical correlations to be made with other Mississippian-Pennsylvanian localities of Mexico and different regions of the United States of America in Texas, Colorado, Illinois and Oklahoma, which were located in the southwestern of the North American Craton. Conclusions: It is considered that the paleoenvironment inferred based on the paleontological records of the Sierra Santa Teresa were shallow seas that allowed the development of communities of crinoids, as well as other invertebrates such as coralline sponges, solitary corals, fenestellid bryozoans and brachiopods, with a range stratigraphic from the Middle-Upper Mississippian (Chesterian) to the Middle Pennsylvanian (Desmoinesian). [ABSTRACT FROM AUTHOR]

Silicified brachiopods from Hirnantian strata in three sections of the lower Whittaker Formation, Mackenzie Mountains, northwestern Canada, yielded a moderately diverse, Edgewood-type Hirnantian fauna, consisting of 13 species: Biparetis paucirugosus, Brevilamnulella laevis, Dalmanella edgewoodensis, Drabovia noixella, Eospirigerina putilla, Epitomyonia paucitropida, Epitomyonia sekwiensis, Glyptorthis papillosa new species, Gnamptorhynchos orbiculoidea, Katastrophomena mackenzii new species, K. parvicardinis, Parastrophina cf. P. minor, and Skenidioides sp. Compared to the typical Edgewood fauna of the American Midcontinent, Brevilamnulella laevis has a notably smaller shell than B. thebesensis, and is interpreted as a deeper-water form. The strong faunal affinity of the Mackenzie Mountains fauna to the Edgewood-type Hirnantian fauna is indicated by the occurrence of Biparetis, Brevilamnulella, Eospirigerina, and Gnamptorhynchos. In addition to the Edgewood type area within Laurentia, Biparetis, Eospirigerina, and Gnamptorhynchos are characteristic taxa that also occur in the Ellis Bay Formation (Hirnantian) of Anticosti Island. Multivariate and network analyses strongly support the differentiation between an Edgewood-type Hirnantian fauna in Laurentia and peri-Laurentia and the typical Hirnantia fauna of the Kosov Province in Gondwana, peri-Gondwana, South China, Kazakhstan terranes, Avalonia, and Baltica. UUID: http://zoobank.org/7ff8f8c8-52d1-4527-acae-9bacd2e8b914 [ABSTRACT FROM AUTHOR]

This study describes an assemblage of Dzieduszyckia brachiopods preserved in sedimentary barite deposits from the Famennian, Upper Devonian of Nevada, USA. The brachiopods lived in a methane-seep environment like those described from Sonora, Mexico, and the Western Meseta, Morocco. Although the original carbonate fabrics are not preserved, pockets of limestone within the brachiopod barite are depleted in with δ13C values ranging from -31.1 to -27.3‰ VPDB. The fossils are preserved as internal and external molds only but record enough detail to demonstrate key internal features of Dzieduszyckia such as a pronounced dorsal septum, septalium, and vertical dental plates. The lack of common bifurcation or trifurcation of the costae as well as larger size of the shells recommends against inclusion within D. sonora as previously published. Based on the number of costae per width of shell, it is possible that there are two distinct species in Nevada, like other localities in Morocco, the Urals, and South China. These new data expand the body of knowledge of these earliest dimerelloids and it is hypothesized that this seep-dwelling macrofauna arose from depauperate-successful lineages between the Famennian biotic crises. As nearly all global Dzieduszyckia deposits are associated with active tectonic margins, it is also suggested that tectonically-driven methane expulsion in low nutrient waters spurred the evolution of dimerelloids. [ABSTRACT FROM AUTHOR]

This study describes an assemblage of Dzieduszyckia brachiopods preserved in sedimentary barite deposits from the Famennian, Upper Devonian of Nevada, USA. The brachiopods lived in a methane-seep environment like those described from Sonora, Mexico, and the Western Meseta, Morocco. Although the original carbonate fabrics are not preserved, pockets of limestone within the brachiopod barite are depleted in with δ13C values ranging from -31.1 to -27.3‰ VPDB. The fossils are preserved as internal and external molds only but record enough detail to demonstrate key internal features of Dzieduszyckia such as a pronounced dorsal septum, septalium, and vertical dental plates. The lack of common bifurcation or trifurcation of the costae as well as larger size of the shells recommends against inclusion within D. sonora as previously published. Based on the number of costae per width of shell, it is possible that there are two distinct species in Nevada, like other localities in Morocco, the Urals, and South China. These new data expand the body of knowledge of these earliest dimerelloids and it is hypothesized that this seep-dwelling macrofauna arose from depauperate-successful lineages between the Famennian biotic crises. As nearly all global Dzieduszyckia deposits are associated with active tectonic margins, it is also suggested that tectonically-driven methane expulsion in low nutrient waters spurred the evolution of dimerelloids. [ABSTRACT FROM AUTHOR]

There was a sudden increase in the diversity of bioclaustrations in the Sandbian (Late Ordovician) that continued somewhat more slowly in the Katian. The Sandbian was also the time when bioclaustrations became common, at least in Baltica. The major increase in the diversity of bioclaustrations in the Late Ordovician was an outcome of the GOBE, and we term it the Ordovician Bioclaustration Revolution. The Ordovician Bioerosion Revolution may partially be responsible for beginning of the Ordovician Bioclaustration Revolution in the Sandbian, as a number of these early bioclaustrations started their growth from initial borings. The diversification of bioclaustrations in the Sandbian involves mostly bryozoans and, to a lesser extent, brachiopods as hosts. The Katian increase in bioclaustration diversity involves mostly corals as the hosts and was likely unrelated or at least less influenced by the Ordovician Bioerosion Revolution. A new broadly conical bioclaustration, Kuckerichnus kirsimaei nov. cgen., nov. csp., is here described from the growth surfaces of hemispherical trepostome bryozoan colonies of Diplotrypa bicornis , Mesotrypa orientalis and Mesotrypa excentrica from the early Sandbian (Late Ordovician) of Estonia. [ABSTRACT FROM AUTHOR]

Linguliformean and craniiformean brachiopods from the Middle and Upper Ordovician of the Brabant Massif (Belgium) are described for the first time and their palaeoecological and palaeobiogeographical implications are discussed. The restricted and generally poorly preserved material was collected from the Abbaye de Villers (Dapingian–Darriwilian) Formation and from the Katian Huet and Fauquez formations. The dark graptolitic mudstones of the latter unit yielded the most diverse assemblage including seven pseudolingulid, obolid, discinid, and craniopsid species while the Abbaye de Villers and Huet formations only yielded one species each. Due to the scarcity of internal morphological details available, comparison of the pseudolingulid and obolid specimens under investigation here was undertaken by running a Principal Component Analysis using a Log-Shape Ratio transformation of linear measurements. The study of valve shape changes at various growth stages helped identify these Belgian specimens at the family and generic levels. Finally, two unusually long (up to 20 mm) shell repair scars are documented in Pseudolingula and reflect predatory attacks at the anterior margin during early growth stages. [ABSTRACT FROM AUTHOR]

The Dapingian (Arenig) siltstones and sandstones of the Tagoat Group, County Wexford, SE Ireland, contain a well-preserved and diverse brachiopod fauna including a new genus of alimbellid, Palaeotagoatia (type species: Orthis Bailyana Davidson) together with the plectorthid Ffynnonia costata (Bates) hibernica nov. subsp. Of the 13 forms documented, at least six are conspecific with brachiopods from the upper Arenig (Dapingian-lowest Darriwilian) Treiorwerth Formation on Anglesey and a further two are identified with species occurring in the older Dapingian Carmel Formation. The faunal province affinities of the fauna are with those assemblages assigned to the peri-insular and marginal Celtic province and which occupied positions within the Middle Ordovician Iapetus Ocean between the Laurentian and Baltic platform provinces. More precise correlation of Middle Ordovician units suggests a significant species richness during the Dapingian-earliest Darriwilian and signalling also an early development of the Celtic province. But the shallow-water siliciclastic facies associated with these islands may also have influenced the distribution of some elements of the Celtic brachiopods and promoted the prevalence of coarse-ribbed orthides, such as Paralenorthis. [ABSTRACT FROM AUTHOR]

A unique, new palaeotaxodont (Protobranchia) genus and species, Yuexiconcha duplicata Zhang, Niu and Johnston, is proposed and described. It is characterized by: a medium-sized, transversely elongated, sub-elliptical shell; heterotaxodont dentition; and posterior tooth row consisting of crowded gradidentate dentition, partially and dorsally overlapped by an additional tooth row that emanates from the beak to form a bitaxodont dentition (new term). Most significantly, a prominent resilifer separates the anterior and posterior tooth rows and shows slight to moderate excavation into the hinge-plate. While a resilifer indicates phylogenetic proximity with Nuculoidea , Yuexiconcha nov. gen. is readily distinguished by its bitaxodont posterior dentition and a more elongate posterior shell lobe and so is provisionally placed in the Family Nuculidae, Order Nuculida. The hinge of Yuexiconcha nov. gen. indicates that a resilifer in palaeotaxodonts first developed in the Ordovician, rather than in the Silurian (Wenlock) as thought previously. Specimens described herein were collected from a fine-grained siliciclastic rock unit in the upper part of the Dongchong Formation in western Guangdong, South China. Other components of the biota occurring with the bivalves are uncommon and include trilobites and brachiopods that indicate a late Middle–early Late Ordovician (late Darriwilian–early Sandbian) age. [ABSTRACT FROM AUTHOR]