Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal e... more Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal evolution is a challenging task, especially for taxa with a mostly poor fossil record, such as sponges (Porifera). 'Lithistida', a polyphyletic group of recent and fossil sponges, are an exception as they provide the richest fossil record among demosponges. Lithistids, currently encompassing 13 families, 41 genera and >300 recent species, are defined by the common possession of peculiar siliceous spicules (desmas) that characteristically form rigid articulated skeletons. Their phylogenetic relationships are to a large extent unresolved and there has been no (taxonomically) comprehensive analysis to formally reallocate lithistid taxa to their closest relatives. This study, based on the most comprehensive molecular and morphological investigation of 'lithistid' demosponges to date, corroborates some previous weakly-supported hypotheses, and provides novel insights into th...
Cenozoic brachiopods, although of low diversity, are commonly found in the fossil benthic communi... more Cenozoic brachiopods, although of low diversity, are commonly found in the fossil benthic communities of Europe and have long been the subject of investigations. Among them, Eocene and Miocene brachiopods are especially well known. In contrast, Oligocene brachiopods were often neglected and only recently have begun to attract the attention of palaeontologists, being described systematically in several papers (e.g.
Brachiopods from the Palaeogene clastic deposits of north-western Italy
Neues Jahrbuch für Geologie und Paläontologie, Nov 26, 2020
Four brachiopod species, i. e. Erymnaria bolcensis ( Massalongo , 1850), Gryphus cf. minor (Phili... more Four brachiopod species, i. e. Erymnaria bolcensis ( Massalongo , 1850), Gryphus cf. minor (Philippi, 1836), Terebratulina tenuistriata (Leymerie, 1846), and Megathiris detruncata (Gmelin, 1791) have been identified in the Oligocene deposits of NW Italy. The species G. cf. minor and T. tenuistriata dominate in the studied material. This is the first record of M. detruncata from the Oligocene of Italy, although it has been noted both from the Eocene and Miocene of Italy. The stratigraphic ranges of E. bolcensis and T. tenuistriata have been extended. The studied assemblage differs considerably from the majority of the Palaeogene and Neogene assemblages of Europe dominated by micromorphic megathyridids. Geological context and sedimentary features point to mass-flow deposits of fan deltas, indicating that the assemblage has been transported within the sediment down a slope.
Zenodo (CERN European Organization for Nuclear Research), Dec 31, 2009
Twenty-two brachiopod species belonging to 19 genera have been recognized in the material collect... more Twenty-two brachiopod species belonging to 19 genera have been recognized in the material collected during two cruises, Norfolk 1 and Norfolk 2, to the Norfolk Ridge south of New Caledonia, at depths of 180 to 1150 m. Thirteen species are reported for the first time from this locality, while four genera, Aulites, Septicollarina, Annuloplatidia and Campages, are noted for the first time from the New Caledonian region. Thecidellina minuta is recorded for the first time from the Pacific. Four new species are described-Cryptopora norfolkensis sp. nov., Aulites crosnieri sp. nov., Septicollarina zezinae sp. nov. and Annuloplatidia richeri sp. nov. The distribution of the particular species and their abundance vary considerably between the 15 sampled seamounts, with Stenosarina crosnieri and Fallax neocaledonensis being most widely distributed, and the seamount Crypthelia having the highest biodiversity. The seamount brachiopods show considerable affinity to the brachiopods of adjacent regions, and only three species-C. norfolkensis, A. crosnieri and A. richeri can be regarded as potential endemics. The brachiopod fauna is more similar to that in the area around Fiji than to that around Australasia.
Six brachiopod species, i.e., Discradisca sp., Cryptopora sp., Pliothyrina sp. cf. P. grandis (Bl... more Six brachiopod species, i.e., Discradisca sp., Cryptopora sp., Pliothyrina sp. cf. P. grandis (Blumenbach, 1803), Terebratulina tenuistriata (Leymerie, 1846), Rhynchonellopsis nysti (Bosquet, 1862), and Orthothyris pectinoides (von Koenen, 1894), have been identified in the Late Eocene to Early Oligocene Silberberg Formation of Atzendorf, Central Germany. The species R. nysti and O. pectinoides dominate the studied assemblage. Rhynchonellopsis is here transferred from the family Cancellothyrididae to Chlidonophoridae because it has a loop without united crural processes. Orthothyris pectinoides has a brachial skeleton of chlidonophorid type, but its transverse band is incomplete. In species composition, the assemblage from Atzendorf differs from other Paleogene and Neogene European assemblages by the absence of megathyridids and dominance of chlidonophorids, indicating a relatively deep environment. Keywords Brachiopoda Á Rhynchonellopsis Á Orthothyris Á Late Eocene Á Early Oligocene Á North Sea Basin Á Germany Kurzfassung Aus der obereozänen bis unteroligozänen Sibergerb-Formation von Atzendorf, Deutschland, konnten sechs Brachiopoden-Arten beschrieben werden: Discradisca sp., Cryptopora sp., Pliothyrina sp. cf. P. grandis (Blumenbach, 1803), Terebratulina tenuistriata (Leymerie, 1846), Rhynchonellopsis nysti (Bosquet, 1862), Orthothyris pectinoides (von Koenen, 1894). Die dominierenden Arten sind R. nysti und O. pectinoides. Aufgrund des Armgerüsts wird Rhynchonellopsis von der Familie Cancellothyrididae in die Familie Chlidonophoridae verschoben. Orthothyris pectinoides hat ein Brachialgerüst vom Chlidonophoriden-Typus. In Hinblick auf die Artzusammensetzung unterscheidet sich die Vergesellschaftung von Atzendorf von anderen europäischen Vergesellschaftungen durch das Fehlen von Megathyrididen und eine Dominanz von Chlidonophoriden, was auf einen relativ tiefen Ablagerungsraum hinweist.
Isotopic disequilibrium in brachiopods disentangled with dual clumped isotope thermometry
Geochimica et Cosmochimica Acta, Aug 1, 2023
Variation of shell ornamentation with latitude and water depth—A case study using living brachiopods
Ecology and Evolution, Apr 1, 2023
As a potential anti‐predatory defensive structure, the shell ornamentation of marine calcifiers i... more As a potential anti‐predatory defensive structure, the shell ornamentation of marine calcifiers is usually used to understand the macro coevolution of the interactions between predators and preys. Marine calcifiers' shell ornamentation complexity is generally believed to vary negatively with latitude and water depth. In this paper, we explored the association between shell ornamentation and latitude/bathymetry using the latest global database of living brachiopods. We found that (1) ~59% of living brachiopods species are characterized by smooth shells and that (2) there is no statistically significant linear trend, either positive or negative, between the ornamentation index and latitudes nor with water depths. Both findings are puzzling for living brachiopods as they are sharply contrasted to the patterns of fossil brachiopods whereby the latter, especially Paleozoic brachiopods, are known to exhibit (1) a much greater ornamentation diversity and (2) (at least for the geological periods that have been studied) a linear latitudinal gradient of ornamentation complexity existed. The reasons why living brachiopods have such a high proportion of smooth or weakly ornamented shells and fail to demonstrate an unequivocal linear latitudinal ornamentation gradient were explored and are linked to a multitude of potential factors rather than uniquely only to the predation pressure. Among these, the most plausible factor seems to be the cryptic (refuge‐type) habitats (e.g., deep waters, cold polar regions, and submarine rock caves) that living brachiopods have been adapted to due to their low metabolism, where predation pressure is low, allowing brachiopods to enact the predator avoidance strategy rather than having to manufacture robust shell ornamentation to survive in an otherwise highly engaged predator–prey global marine ecosystem.
Rhynchonellid brachiopods from the Oligocene of King George Island, West Antarctica
Phylum Brachiopoda, shelled marine invertebrates, is currently represented by about 400 extant sp... more Phylum Brachiopoda, shelled marine invertebrates, is currently represented by about 400 extant species; a tiny fraction of the ca. 30,000 described fossil species (Emig et al. 2013; Bitner 2014; Nauendorf et al. 2014; Logan et al. 2015). Only twenty of these Recent species are known from the Chilean coasts (Lee et al. 2008), most of them from subtidal waters. Of these, only Magellania venosa (Dixon, 1789) (the largest extant brachiopod) and Discinisca lamellosa (Broderip, 1833) are common species found in the southern and central-northern coasts of the country, respectively. As with other marine invertebrates, brachiopods from the region have been reviewed in few studies, apart from some classic nineteenth century works by Sowerby (
Zoological Journal of the Linnean Society, Jan 29, 2015
We present five case studies among articulate (rhynchonelliform) brachiopods, i.e. of Rhynchonell... more We present five case studies among articulate (rhynchonelliform) brachiopods, i.e. of Rhynchonellida, Cancellothyridoidea, Terebratuloidea, Dyscolioidea, Laqueoidea, and various terebratulids with modified long-loops, in an attempt to illustrate and better understand congruence and conflict between morpho-classification and rDNA-based molecular clade structure, having been prompted to address these issues by difficulties encountered when describing the newly collected brachiopod, Ebiscothyris bellonensis gen. et sp. nov. The five studies reveal dramatic conflict in the Rhynchonellida and Terebratuloidea/Dyscolioidea, good congruence in the Cancellothyridoidea and Laqueoidea, and fair congruence (albeit with weak phylogenetic signal) in the long-looped terebratulids. We suggest that the leading cause of the observed conflict lies in the use of inadequately specific morphological characters and morphoclassification. Phylogenetic systematic (cladistic) analyses of Rhynchonellida also conflict markedly with the rDNA gene tree, leading us to recognize that such analyses are not only conceptually circular (using morphological characters to assess a morphological classification) but also to propose that they are biased by the act of classification that necessarily precedes the identification of putatively homologous characters; when the prior classification does not reflect evolutionary history, phylogenetic analysis will do likewise. In addition, we propose that the brachiopod community has overlooked the significance of two sources of morphological homoplasy affecting brachiopod systematics: (1) the loss of co-adapted genomic complexes caused by mass extinctions at the end of the Permian; and (2) the pervasive consequences of developmental integration and constraint resulting from the integrated roles of the outer mantle epithelium in shell deposition and growth that underly the determination of form and the shell-based classification.
two brachiopod species Discradisca indica (dall, 1920) and Argyrotheca jacksoni cooper, 1973, tog... more two brachiopod species Discradisca indica (dall, 1920) and Argyrotheca jacksoni cooper, 1973, together with Lingula sp., have been identified from the Persian gulf. these species, added to the two species Terebratulina retusa (linnaeus, 1758) and Megerlia truncata (linnaeus, 1767) previously identified by Jackson (1921), and Lingula anatina lamarck, 1819 by emig (1988) bring the total to 5 species for the region. the genera Discradisca and Argyrotheca are recorded for the first time from the Persian gulf. this fauna shows biogeographical affinities to the indian ocean and the Mediterranean faunas. the disjunct geographical distribution of Discradisca suggests this genus is a relict of an ancient tethyan fauna.
Biodiversity of shallow-water brachiopods from New Caledonia, SW Pacific, with description of a new species
Scientia Marina, Jul 1, 2010
Interhemispheric biodiversity peaks of living brachiopods coinciding with warm-temperate zones and correlated to a multitude of biotic, abiotic and evolutionary factors
Zenodo (CERN European Organization for Nuclear Research), Dec 31, 2007
Four Recent brachiopod species, including one new, Acrobrochus marotiriensis n. sp., Dallithyris ... more Four Recent brachiopod species, including one new, Acrobrochus marotiriensis n. sp., Dallithyris pacifica Bitner, 2006, Megerlia truncata (Linnaeus, 1767) and Thecidellina maxilla (Hedley, 1899), have been recognised in the material collected during the French BENTHAUS Expedition to the Austral Islands (French Polynesia) in 2002. The Austral Islands are situated on the southeastern limit of the Indo-West Pacific biogeographic Province. This is the first record of brachiopods from off the Australs. Dallithyris pacifica, M. truncata and T. maxilla have been already reported from the southern Pacific, while the genus Acrobrochus is noted for the first time from the Pacific. Acrobrochus marotiriensis n. sp. belongs to the short-looped brachiopods. Its loop is characterized by a very broad, gently folded transverse band. The triangular outer hinge plates are margined by a small elevation of the crural bases. This species differs from congeneric species in its smaller size, its less elongate outline and its greater convexity. rÉsUMÉ Brachiopodes actuels des îles Australes, Polynésie française, Pacifique sud-central. Quatre espèces de brachiopodes actuels, dont une nouvelle, Acrobrochus marotiriensis n. sp., Dallithyris pacifica Bitner, 2006, Megerlia truncata (Linnaeus, 1767) et Thecidellina maxilla (Hedley, 1899), ont été identifiées dans le matériel récolté pendant l'expédition française BENTHAUS aux îles Australes (Polynésie française) en 2002. Les îles Australes sont situées en limite sud-est de la province biogéographique Indo-Ouest Pacifique. Des brachiopodes y sont signalés pour la première fois dans la région des Australes. Dallithyris pacifica, M. truncata et T. maxilla avaient déjà été trouvées dans le Pacifique Sud, mais le genre Acrobrochus est signalé pour la première fois du Pacifique. Acrobrochus marotiriensis n. sp. appartient aux brachiopodes ayant une boucle courte. Sa boucle se caractérise par une bande transverse très large, légèrement pliée. Les plaques cardinales sont triangulaires et bordées par une élévation des bases crurales. Cette espèce se distingue des autres espèces du genre par sa taille plus petite, sa forme générale moins allongée et sa convexité plus grande.
Are fossil brachiopod geochemical analyses biased by cement-filled puncta?
EGU General Assembly Conference Abstracts, Apr 1, 2018
Due to their resistance to diagenesis, fossil brachiopods have extensively been used as archives ... more Due to their resistance to diagenesis, fossil brachiopods have extensively been used as archives in paleoenviron-mental studies. Most analyses on fossil brachiopods focus on carbon and oxygen stable isotopes, minor and traceelements, and most of the analyses are still done on the bulk of the shell’s low-Mg calcite (LMC). Despite thehuge progress made over the years on the cleaning procedures in order to avoid contaminations, analytical biasescaused by the brachiopod puncta, filled with diagenetic carbonate cement, has not been addressed so far. Here wepresent a preliminary investigation on the chemical differences that this secondary cement might have if comparedto the biogenic calcite nucleated by the brachiopod. Cenozoic specimens of Megerlia truncata, one Gryphus kickxiand one of Terebratula sinuosa were studied from different locations and outcrops. Electron microprobe analysisin wavelength dispersive mode was done in order to measure the Ca, Mg, Sr, Mn, Fe, Ba, Al, P and Si content in avalve’s thin section, targeting both biogenic calcite of the shell and the cement in the puncta. Results show a clearoffset only in G. kickxi, with all the targeted puncta having much higher Fe and Mg contents. M. truncata and T.sinuosa specimens are more homogeneous and with less distinct chemical differences between puncta and shellcalcite. Such differences might be easily explained by different diagenetic stages: e.g. similar in M. truncata andT. sinuosa, and basically different in G. kickxi. The case of G. kickxi points at the possible analytical biases thatpuncta might cause even in well preserved specimens. The differences in chemical composition that we observedare not species specific, although they might be influenced by puncta size, but rather related to the depositionalenvironment and geological history of the depositional basin. A large scale survey is needed to more accuratelyunderstand the influence of infilled puncta across a large variety of geological settings. This will ultimately lead toa better calibration of geochemical proxies when using brachiopod shell geochemistry as environmental archives
Decadal climate variation recorded in modern global carbonate archives (brachiopods, molluscs)
Brachiopods are entirely marine, sessile, benthic invertebrates with soft body enclosed in a shel... more Brachiopods are entirely marine, sessile, benthic invertebrates with soft body enclosed in a shell consisting of two valves which differ in size, shape, and sometimes even in ornamentation and colour. Most brachiopods have calcareous shell, except lingulids which have organophosphatic shell. They have a very long and impressive geological history but today they are regarded as a minor phylum and are reduced to about 110 genera. Nevertheless, brachiopods are widely distributed, being present in all of the world's oceans and they can locally dominate the benthic marine communities. Their bathymetric range is very wide, from the intertidal zone to depths of about 6000 meters, however, most commonly they occur from 100 to 500 m. Among the 30 brachiopod species occurring in the New Caledonia region (d'Hondt 1987; Emig 1988; Laurin 1997), only four of them have been found in the shallow water less than 100 meters deep. The shallow water brachiopod fauna consists of 4 species belonging to 3 genera, in 3 families, 3 orders (Lingulida, Terebratulida and Thecideida) and 2 subphyla (Linguliformea and Rhynchonelliformea). Two Lingula species, namely L. anatina Lamarck and L. adamsi Dall, are recognised in New Caledonia. Lingulides are the only brachiopods which adopted an infaunal habit in soft sediments. Those two species are widely distributed in the West Pacific. As in many West Pacific islands until Japan, the lingulides are cooked and eaten in New Caledonia where they are named "moules à queue" (more details in the local newspaper of Nouméa "Les Nouvelles" 25/10/1983 and 4/11/1983 (C. Emig, personal communication). Frenulina sanguinolenta (Gmelin, 1791) is the only terebratulide found in shallow waters. This species is easily recognisable because of its red colour pattern. It lives attached by a pedicle to the hard substrate. F. sanguinolenta is reported from many localities in the Pacific Ocean, from Japan and Australia to Hawaii and French Polynesia, as well as in the Indian Ocean. The fourth brachiopod species known from the shallow water is a thecideid, Thecidellina maxilla (Hedley). The thecideid brachiopods are small cementing forms which live in low to mid-latitudes. They inhabit commonly light-poor, shallow water environments, such as caves and crevices in coral reefs. T. maxilla is widespread in the Pacific Ocean, from Tuvalu to the Tuamotu Islands, and as far south as the Kermadec Islands.
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