Recent Brachiopods Research Articles

New records and descriptions of recent Australian brachiopods (Terebratulida, Dallinidae and Aulocothyropsidae; and Rhynchonellida, Frieleiidae)

The recent brachiopod fauna of Australia remains poorly understood with several species lacking upto-date descriptions, and with many unidentified or misidentified specimens in museum collections. A large collection of brachiopods housed at the Tasmanian Museum and Art Gallery was recently examined to allow the re-description of two Australian endemic Dallinid brachiopods, Jaffaia jaffaensis and Campages furcifera, and identify new species and species occurrences. Furthermore, the large number of specimens allowed ecological aspects to be explored. As a result, the morphology and variation of C. furcifera and J. jaffaensis were clarified and expanded, a new deep-sea Dallinid species, Dallina tasmaniaensis, sp. nov. was described, the first occurrence of this genus from Australia, and the deep-sea Aulocothyropsid species Fallax neocaledonensis and Rhynchonellid Neorhynchia strebeli were also recorded from Australia for the first time. Jaffaia was revealed to be far more alike Nipponithyris than previously appreciated. The morphometric relationships of the three Dallinid species were found to differ significantly, with the attachment substrata and epibiota particularly prominent and diverse for J. jaffaensis and C. furcifera. This research facilitates the improved identification of Australian brachiopods, significantly increases understanding of variation within local species, and highlights the underappreciated biodiversity of deep-sea brachiopods in Australian waters.

Change in Predominant Growth Trajectories in the Ontogeny of Recent Brachiopods

Change in Predominant Growth Trajectories in the Ontogeny of Recent Brachiopods

Recent brachiopod diversity and distribution from the central Cantabrian Sea and the Avilés Canyons System (Bay of Biscay)

An accurate knowledge of the species diversity from deep-sea ecosystems is an imperative requirement in order to protect these environments in the context of global change and the biodiversity loss. We have examined the Brachiopoda samples collected during the COCACE (1987–88) and BIOCANT (2012–13) oceanographic cruises, from the central Cantabrian Sea and the Avilés Canyons System (ACS). The ACS is included in the Natura 2000 as a Site of Community Importance. Brachiopod specimens were collected from the continental shelf, slope and bathyal zones, ranging in deep from 117 to 4700 m. Nine hundred and thirty specimens belonging to 15 taxa (12 species and three subspecific varieties), in 12 families, were recognized. The species Dyscolia subquadrata is reported for the first time in the study area, constituting a new record from the Cantabrian Sea. We provide brief notes about the ecology and distribution of the collected species from the study area. Furthermore, we trace the biogeographical history of the involved species and review their main substrate and bio-depth zone preferences.

Description and figures of new lectotype and paralectotype material of Recent brachiopod Thecidellina maxilla (Hedley, 1899)

Description and figures of new lectotype and paralectotype material of Recent brachiopod Thecidellina maxilla (Hedley, 1899)

Lithium elemental and isotope systematics of modern and cultured brachiopods: Implications for seawater evolution

Lithium has proven a powerful tracer of weathering processes and chemical evolution of seawater. Skeletal components of marine calcifying organisms, and in particular brachiopods, present promising archives of Li signatures. However, Li incorporation mechanisms and potential influence from biological processes or environmental conditions require a careful assessment. In order to constrain Li systematics in brachiopod shells, we present Li concentrations and isotope compositions for 11 calcitic brachiopod species collected from six different geographic regions, paralleled with data from culturing experiments where brachiopods were grown under varying environmental conditions and seawater chemistry (pH–pCO2, temperature, Mg/Ca ratio). The recent brachiopod specimens collected across different temperate and polar environments showed broadly consistent δ7Li values ranging from 25.2 to 28.1‰ (with mean δ7Li of 26.9 ± 1.5‰), irrespective of taxonomic rank, indicating that incorporation of Li isotopes into brachiopod shells is not strongly affected by vital effects related to differences among species. This results in Δ7Licalcite–seawater values (per mil difference in 7Li/6Li between brachiopod calcite shell and seawater) from −2.9‰ to −5.8‰ (with mean Δ7Licalcite–seawater value of −3.6‰), which is larger than the Δ7Licalcite–seawater values calculated based on data from planktonic foraminifera (~0‰ to ~−4‰). This range of values is further supported by results from brachiopods cultured experimentally. Under controlled culturing conditions simulating the natural marine environment, the Δ7Licalcite–seawater for Magellania venosa was −2.5‰ and not affected by an increase in temperature from 10 to 16 °C. In contrast, a decrease in Mg/Ca (or Li/Ca) ratio of seawater by addition of CaCl2 as well as elevated pCO2, and hence low-pH conditions, resulted in an increased Δ7Licalcite-seawater up to −4.6‰. Collectively, our results indicate that brachiopods represent valuable archives and provide an envelope for robust Li-based reconstruction of seawater evolution over the Phanerozoic.

Biomacromolecules in recent phosphate-shelled brachiopods: identification and characterization of chitin matrix

Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these animals are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate to provide a sophisticated ultrastructural robustness. This investigation examined the nature of the organic fibres in order to improve understanding of how living organisms produce hierarchically structured biomaterials. Unlike powdered samples commonly used in previous studies, organic fibres were isolated for the first time and the shell fractions were purified, in order to study the content and nature of the biopolymer fibres. Biochemical methods including Calcofluor staining revealed a chitin matrix. Ultrastructural analysis, thermal gravimetric analysis, and spectroscopic analyses show that the core polysaccharide framework is composed of layers of β-chitin sheets and/or fibrils that are coated with a fibrous organic matrix. There is more chitin matrix in the L. anatina shells (26.6 wt.%) compared to the D. tenuis shells (12.9 wt.%). Taken together, the data show that the chitin matrix contributes to increased skeletal strength, making L. anatina highly adapted for life as an active burrower. In comparison, D. tenuis contains less chitin and lives as attached epibenthos in a shallow marine environment.Graphical abstractFirst spectroscopic evidence of β-chitin sheets in recent organophosphatic brachiopods

Taxonomic composition and assemblage structure of brachiopods from two submarine caves in the Aegean Sea, Eastern Mediterranean

Brachiopods exhibit a particular preference for cryptic habitats such as submarine caves. However, their assemblages have rarely been investigated quantitatively in this habitat. In this work, brachiopod assemblages were studied in detail for the first time in two Aegean submarine caves, Fara and Agios Vasilios, Lesvos Island, Eastern Mediterranean Sea. Six species of Recent brachiopods, i.e. Novocrania turbinata (Poli, 1795), Tethyrhynchia mediterranea Logan, 1994, Megathiris detruncata (Gmelin, 1791), Argyrotheca cuneata (Risso, 1826), A. cistellula (Searles–Wood, 1841), and Joania cordata (Risso, 1826), have been identified. The cave-exclusive species Tethyrhynchia mediterranea is reported for the first time from the Aegean Sea and Greek waters, increasing the regional brachiopod fauna to 13 species, and for the second time in the Eastern Mediterranean. Five species were present in both caves while T. mediterranea was found only in the internal dark ceilings and walls of Fara cave. In both caves the dominant species was Argyrotheca cuneata. Abundance and diversity increased towards the internal dark ceilings of both caves, which harboured a well-differentiated brachiopod assemblage compared to that of the outer cave zones.

The shell fabric of Palaeozoic brachiopods: patterns and trends

The varied microstructures of brachiopod biominerals represent a robust archive to understand the evolution and adaptations of marine calcifiers in time. Therefore, a detailed study of the shell microstructure of Cambrian to Devonian brachiopods from Iran is here presented. The shell of 38 brachiopod species, representatives of 22 families and nine orders, has been analysed using scanning electron microscope (SEM), and a database has been built, including macro- and micro-morphological features used to characterize the two- or three-layered brachiopod shells. Two main microstructural variants of the secondary layer have been analysed: fibrous and laminar fabrics. The fibrous layer has a fabric comparable to that of recent brachiopods, whereas the laminar fabric is more complex in its structural organization and has no recent analogue. In cross-section, the laminae are thinner than the fibres, and much less variable in size. There is evidence that taxa with laminar microstructure have diverged from the Billingsellida and then followed a trend implying a decrease in thickness of the laminae. Our linear discriminant analysis (LDA) shows that shell fabric and shell thickness are powerful predictors of shell shapes, which in turn approximate the brachiopod lifestyles and ecological strategies. Taxa with a fibrous fabric are mostly biconvex, whereas the groups with a laminar secondary layer are associated to a variety of shell shapes and lifestyles. Even if the relations between shell fabric and shell thickness remain enigmatic, as well as the metabolic cost they imply, shell fabrics, and the possible structural and mechanical advantages conferred, could have played a role in the evolutionary success of the Strophomenata during the Palaeozoic.

New records of Recent brachiopods (Terebratulida) from the northern Mid-Atlantic Ridge

ABSTRACT Five species of Recent brachiopods (Terebratulida), i.e. Xenobrochus parvus (Cooper, 1977), Chlidonophora incerta (Davidson, 1878), Eucalathis ergastica Fischer & Œhlert, 1890, Nanacalathis atlantica Zezina 1991, and Leptothyrella incerta (Davidson, 1880) have been identified in the material collected during the 39th cruise of the RV Professor Logachev in the Russian Exploration Area in the central part of the northern Mid-Atlantic Ridge in February–March 2018. Only Chlidonophora incerta is numerous, the remaining species are very rare. This is the first confirmed occurrence of the genus Xenobrochus from the Atlantic Ocean. The distribution of the studied fauna and its comparison with adjacent regions are also discussed.

A New Record of Recent Brachiopods: Digitizing the National Natural History Collections, The Hebrew University Of Jerusalem

Brachiopods (lamp-shells) are a group of macrobenthic invertebrates with a remarkably long fossil record that encompasses deep time to modern-day oceans with over 12,000 species reported in the fossil record. In contrast, today brachiopods form a relatively small independent phylum among the invertebrates that includes only ca. 350 living species. Brachiopods are commonly used to examine faunal response to changes in the depositional environment across space and time. The extinct fossil species are compared to their counterparts from modern settings in order to find associations between ecological and morphological traits and past environmental conditions. Thus, collecting data on living brachiopods and studying their ecological preferences is crucial to the understanding of ancient environments. Until today, only scarce information has been published on extant brachiopods in the Levantine Basin off the coast of Israel. The current curatorial state of collections from the area prevents us from realizing their full scientific potential. We present new information concerning brachiopods collected in the Eastern Mediterranean and stored in the Mollusc Collection of the National Natural History Collections, The Hebrew University of Jerusalem. The collection is based on personal contributions and material collected by the Sea Fisheries Research Station during annual surveys carried out along the coast of Israel. As a first step, we estimated the size of the collection to contain ca. 355 samples of brachiopods of an unknown number of species. Notable contributions to the brachiopod collection include the Giorgio S. Coen and the Arthur Blok collections. Giorgio S. Coen, an enthusiastic malacologist, donated his private collection in 1951. The collection includes samples given to Coen by the distinguished Marchese di Monterosato, and contains ca. 230 samples of recent worldwide brachiopods. So far we have recognized type material of at least four taxa in the Coen collection. In addition, the Arthur Blok collection was donated in 1974 and includes ca. 65 samples of recent brachiopods. Due to the limited number of extant species, new records of living brachiopods should prove to be an important contribution to future studies in biogeography, phylogeny and the study of paleoenvironments. Our preliminary results show species occurrences in undocumented depths and habitats of the Eastern Mediterranean, and points to higher estimation of diversity in the Eastern Mediterranean than previously assumed. The order of magnitude difference in species diversity between extant and fossil brachiopods means our new information on life modes and habitats of recent species may have a significant effect on paleoecological reconstruction of their fossil counterparts. Thus, our new record of recent Levantine brachiopods can improve their use as reliable proxies for reconstructing environmental conditions throughout the fossil record.

RECENT BRACHIOPODS FROM THE TONGA ISLANDS, SW PACIFIC: TAXONOMY AND BIOGEOGRAPHY

Twenty species of Recent brachiopods belonging to the genera Neoancistrocrania, Basiliola, Basiliolella, Dyscolia, Abyssothyris, Xenobrochus, Terebratulina, Fallax, Septicollarina, Frenulina, Amphithyris, Annuloplatidia, Leptothyrella, Dallina, Campages, Thecidellina and Minutella have been identified in the material collected during the French cruise Bordau 2 to the Tonga Islands, South-West Pacific. Apart from Frenulina sanguinolenta all species represent the first records for the Tonga Islands. The investigated brachiopod fauna shows the greatest affinity to that from Fiji and New Caledonia, having 16 and 12 species in common, respectively. Although less affinity is observed with the New Zealand fauna, there are two species, Terebratulina australis and Amphithyris buckmani reported so far only from New Zealand, Fiji and Tonga. The biodiversity of brachiopods inTonga is similar to that inFiji but half as great as that inNew Caledonia andNew Zealand regions and much higher than inFrench Polynesia.

Spermatogenesis in the deep-sea brachiopod Pelagodiscus atlanticus and the phylogenetic significance of spermatozoon structure.

Details of spermatogenesis and sperm organization are often useful for reconstructing the phylogeny of closely related groups of invertebrates. Development in general and gametogenesis in particular usually differ in shallow water and deep-sea invertebrates. Here, the spermatogenesis and ultrastructure of sperm were studied in the deep-sea brachiopod Pelagodiscus atlanticus. The testes of P. atlanticus are voluminous sacs located along the lateral sides of the body. Germ cells develop around the blood capillaries, contact the basal lamina, and contain germ plasm, numerous mitochondria, Golgi apparatus, lipid droplets, and centrioles of the rudimentary cilium. During spermatogenesis, several proacrosomal vesicles appear at the posterior pole of the cell; these vesicles then fuse and migrate to the anterior pole. The spermatozoon has a head with an acrosome, nucleus, eight mitochondria, proximal and distal centrioles orthogonally arranged, and a long tail. Comparative analysis suggests that the spermatozoon of P. atlanticus can be considered the most ancestral among all brachiopods. Such an organization indicates that fertilization is external in this deep-sea species. Spermatozoa of other brachiopods should be regarded as derived from this ancestral type. The transformation of brachiopod spermatozoa might have occurred in three different ways that correspond to the three main clades of recent brachiopods: Linguliformea, Craniiformea, and Rhynchonelliformea.

Extreme reduction of morphological characters: a type of brachidial development found in several Late Cretaceous and Recent brachiopod species-new relationships between taxa previously listed as incertae sedis.

Size reduction and development of a simplified brachidial structure occurred several times during the long evolution of the Phylum Brachiopoda. Even Recent forms may be micromorphic and paedomorphic with reduced brachidia or none at all. A revision of the Maastrichtian (Late Cretaceous) Terebratella (Morrisia?) suessi Bosquet, 1859 has allowed us to erect a new genus, Jagtithyris gen. nov., because its singular brachidium development does not match any platidiid structure. Such a brachidium has also been observed in another European Late Cretaceous brachiopod, which indicates that this type was not a unique morphological curiosity. This species is the micromorphic Campanian-Maastrichtian Leptothyrellopsis polonicus Bitner Pisera, 1979, which has brachidial structures in common with Jagtithyris suessi comb. nov., although a number of differences have been observed. The genera Leptothyrellopsis and Jagtithyris gen. nov., are included in a new family, Jagtithyrididae fam. nov. During an ongoing revision of extant brachiopod faunas we have been led to recognize a link between this family and representatives of the genus Simplicithyris Zezina, 1976. The taxonomic position of this peculiar group is also discussed.

Recent brachiopods collected during the ZhongSha 2015 expedition to the South China Sea, West Pacific

ABSTRACTFourteen species of Recent brachiopods belonging to the genera Novocrania, Basiliola, Acanthobasiliola, Gryphus, Zygonaria, Terebratulina, Eucalathis, Laqueus, Frenulina, Annuloplatidia, Phaneropora, Dallina and Campages have been identified in the samples collected during the French–Taiwanese ZhongSha 2015 expedition to the South China Sea, West Pacific. Five species were already described from this region. The remaining species represent first records for the South China Sea, among them two species, Annuloplatidia curiosa and Phaneropora galatheae are recorded for the first time in the northern hemisphere.

A SAMPLING STRATEGY FOR RECENT AND FOSSIL BRACHIOPODS: SELECTING THE OPTIMAL SHELL SEGMENT FOR GEOCHEMICAL ANALYSES

Recent and fossil brachiopod shells have a long record as biomineral archives for (palaeo)climatic and (palaeo)environmental reconstructions, as they lack or exhibit limited vital effects in their calcite shell and generally are quite resistant to diagenetic alteration. Despite this, only few studies address the issue of identifying the best or optimal part of the shell for geochemical analyses. We investigated the link between ontogeny and geochemical signatures recorded in different parts of the shell. To reach this aim, we analysed the elemental (Ca, Mg, Sr, Na) and stable isotope (δ18O, δ13C) compositions of five recent brachiopod species (Magellania venosa, Liothyrella uva, Aerothyris kerguelensis, Liothyrella neozelanica and Gryphus vitreus), spanning broad geographical and environmental ranges (Chile, Antarctica, Indian Ocean, New Zealand and Italy) and having different shell layer successions (two-layer and three-layer shells). We observed similar patterns in the ventral and dorsal valves of these two groups, but different ontogenetic trends by the two- and three-layer shells in their trace element and stable isotope records. Our investigation led us to conclude that the optimal region to sample for geochemical and isotope analyses is the middle part of the mid-section of the shell, avoiding the primary layer, posterior and anterior parts as well as the outermost part of the secondary layer in recent brachiopods. Also, the outermost and innermost rims of shells should be avoided due to diagenetic impacts on fossil brachiopods.

Mapping of recent brachiopod microstructure: A tool for environmental studies.

Shells of brachiopods are excellent archives for environmental reconstructions in the recent and distant past as their microstructure and geochemistry respond to climate and environmental forcings. We studied the morphology and size of the basic structural unit, the secondary layer fibre, of the shells of several extant brachiopod taxa to derive a model correlating microstructural patterns to environmental conditions. Twenty-one adult specimens of six recent brachiopod species adapted to different environmental conditions, from Antarctica, to New Zealand, to the Mediterranean Sea, were chosen for microstructural analysis using SEM, TEM and EBSD. We conclude that: 1) there is no significant difference in the shape and size of the fibres between ventral and dorsal valves, 2) there is an ontogenetic trend in the shape and size of the fibres, as they become larger, wider, and flatter with increasing age. This indicates that the fibrous layer produced in the later stages of growth, which is recommended by the literature to be the best material for geochemical analyses, has a different morphostructure and probably a lower organic content than that produced earlier in life. In two species of the same genus living in seawater with different temperature and carbonate saturation state, a relationship emerged between the microstructure and environmental conditions. Fibres of the polar Liothyrella uva tend to be smaller, rounder and less convex than those of the temperate Liothyrella neozelanica, suggesting a relationship between microstructural size, shell organic matter content, ambient seawater temperature and calcite saturation state.

Recent brachiopods from the South China Sea, NW Pacific

Three articulated brachiopod species have been recognized in material collected during the 2014 French-Taiwanese cruise DongSha to the South China Sea, NW Pacific: Terebratulina japonica (Sowerby, 1846), Macandrevia sp. and Nipponithyris afra Cooper, 1973. Nipponithyris afra is noted for the first time from the Northern Hemisphere and the genus Macandrevia is reported for the first time from the West Pacific. All species are reported for the first time from the South China Sea, extending their biogeographical range.

Checklist of recent brachiopod species collected during the Terrasses and Exbodi cruises in the New Caledonian region, SW Pacific.

Twenty species belonging to 16 genera, i.e. Neoancistrocrania, Novocrania, Basiliola, Basiliolella, Ebiscothyris, Stenosarina, Kanakythyris, Xenobrochus, Terebratulina, Eucalathis, Fallax, Frenulina, Septicollarina, Campages, Annuloplatidia, and Thecidellina have been identified in the material collected during the Terrasses and Exbodi cruises in the New Caledonian region, SW Pacific. The species Basiliolella grayi (Woodward, 1855) and Fallax neocaledonensis Laurin, 1997 are the most common in the studied collection, while Eucalathis murrayi (Davidson, 1878) is reported for the first time from the New Caledonian region.

Primary layer of some Rhynchonelliformean brachiopods

The most widespread types of micro- and nanostructure of primary layer of recent and fossil rhynchonelliformean brachiopods are reviewed.

Revision of the brachiopod genus Amphithyris (Rhynchonelliformea: Platidiidae) with descriptions of two new species.

The recent brachiopod genus Amphithyris Thomson belongs to the family Platidiidae and to date comprises five species, A. seminula (Philippi, 1836), A. buckmani Thomson, 1918, A. hallettensis Foster, 1974, A. richardsonae Campbell & Fleming, 1981 and A. parva MacKinnon, Hiller, Long & Marshall, 2008. Like other platidiid genera, Amphithyris has a worldwide distribution, but is mainly found in the southern hemisphere, with the exception of A. seminula which occurs in the Mediterranean Sea. This study is the first revision of the genus Amphithyris. We describe two new species, A. cavernicola n. sp. from the Queensland Plateau, Coral Sea, Australia and A. comitodentis n. sp. from deep waters east of the South Island, New Zealand. A. cavernicola n. sp. represents the first record of the genus from Australian waters, whereas A. comitodentis n. sp. is the first species in the genus recorded from the deep sea. Additionally, we identified the type material of A. seminula in the brachiopod collection of the Museum für Naturkunde, Berlin and designated a lectotype for this species. Despite their simple shell morphology and few diagnostic features, we were able to clearly discriminate the (now) seven species by morphological (shell) characters such as absence/presence of a median septum, absence/presence of capillae, shell convexity and/or combinations of these. On the basis of all known records, the present distribution of Amphithyris spp. and a Cretaceous origin of the genus is discussed.