The Nature of Siliceous Mosaics Forming the First Shell of the Brachiopod Discinisca

Williams, Alwyn; Lüter, Carsten; Cusack, Maggie

doi:10.1006/jsbi.2001.4366

Cited by 29 publications

(37 citation statements)

References 10 publications

(13 reference statements)

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“…Discinids and lingulids are the only extant forms with chitinophosphatic shells, long-lived, planktotrophic juveniles, and Early Palaeozoic origins. Moreover, extant discinids and many extinct lingulids share a distinctive, mosaic ornamentation of the earliest larval shell, in the former by silica tablets, in the latter of unknown composition (Williams et al 1998(Williams et al , 2001.…”

Section: Taxon Selection and Rooting Proceduresmentioning

confidence: 99%

Molecular evidence that phoronids are a subtaxon of brachiopods (Brachiopoda: Phoronata) and that genetic divergence of metazoan phyla began long before the early Cambrian

Cohen

Weydmann

2005

Organisms Diversity & Evolution

136

113

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Concatenated SSU (18S) and partial LSU (28S) sequences ($2 kb) from 12 ingroup taxa, comprising 2 phoronids, 2 members of each of the craniid, discinid, and lingulid inarticulate brachiopod lineages, and 4 rhynchonellate, articulate brachiopods (2 rhynchonellides, 1 terebratulide and 1 terebratellide) were aligned with homologous sequences from 6 protostome, deuterostome and sponge outgroups (3964 sites). Regions of potentially ambiguous alignment were removed, and the resulting data (3275 sites, of which 377 were parsimony-informative and 635 variable) were analysed by parsimony, and by maximum and Bayesian likelihood using objectively selected models. There was no base composition heterogeneity. Relative rate tests led to the exclusion (from most analyses) of the more distant outgroups, with retention of the closer pectinid and polyplacophoran (chiton). Parsimony and likelihood bootstrap and Bayesian clade support values were generally high, but only likelihood analyses recovered all brachiopod indicator clades designated a priori. All analyses confirmed the monophyly of (brachiopods+phoronids) and identified phoronids as the sister-group of the three inarticulate brachiopod lineages. Consequently, a revised Linnean classification is proposed in which the subphylum Linguliformea comprises three classes: Lingulata, 'Phoronata' (the phoronids), and 'Craniata' (the current subphylum Craniiformea). Divergence times of all nodes were estimated by regression from node depths in non-parametrically rate-smoothed and other chronograms, calibrated against palaeontological data, with probable errors not less than 50 My. Only three predicted brachiopod divergence times disagree with palaeontological ages by more than the probable error, and a reasonable explanation exists for at least two. Pruning long-branched ingroups made scant difference to predicted divergence time estimates. The palaeontological age calibration and the existence of Lower Cambrian fossils of both main brachiopod clades together indicate that initial genetic divergence between brachiopod and molluscan (chiton) lineages occurred well before the Lower Cambrian, suggesting that much divergence between metazoan phyla took place in the Proterozoic.

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Section: Taxon Selection and Rooting Proceduresmentioning

confidence: 99%

Molecular evidence that phoronids are a subtaxon of brachiopods (Brachiopoda: Phoronata) and that genetic divergence of metazoan phyla began long before the early Cambrian

Cohen

Weydmann

2005

Organisms Diversity & Evolution

136

113

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“…The rows of smaller hemispherical vesicular pits (Fig. 6H) are present already on the lamellar ring of the Acrosaccus shell (see Williams et al 2001, Williams 2003. Evidence of distinct imprints of tablets in the first-formed shell indicates that this type of pitting already appeared, if not earlier, in the Silurian and early Devonian discinoids.…”

Section: Acrosaccus Spmentioning

confidence: 92%

“…The microornament of the larval shell consists of small slightly concave and convex elliptical pits that evidently represent imprints of the siliceous tablets present in extant discinoids (Williams et al 1998(Williams et al , 2001). The same ornament is known in other species assigned to Acrosaccus (Holmer 1987, Holmer & Popov 2000.…”

Section: Acrosaccus Spmentioning

confidence: 99%

Lingulate brachiopods from the Acanthopyge Limestone (Eifelian) of the Barrandian, Czech Republic

Mergl¹

2008

Bull. Geosci.

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The lingulate brachiopod fauna of the mid-Devonian Acanthopyge Limestone, Choteč Formation of the Prague Basin, Czech Republic comprises seven species, of which Kosagitella pulsatilla sp. nov., Microbolus minimus gen. et sp. nov., Chynithele amoena sp. nov., and Opatrilkiella kobyla sp. nov. are described as new. Shell microornaments of all taxa are examined. The pitting on the mature shell of Kosagitella, and diverse types of pitting on discinid shells have been observed, including the imprints of suggested siliceous tablets on the first-formed shells of Acrosaccus and Opatrilkiella

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“…Examples include loricate choanoflagellates (Leadbeater et al, 2009), thaumatomonads (Scoble and Cavalier-Smith, 2014), chrysophytes (van Tol et al, 2012), and ascidians (Monniot et al, 1992). Repeatedly we can observe the evolution of similar morphologies in distantly related taxa, such as micropores in the siliceous components of choanoflagellates (Leadbeater, 2015), chrysophytes (Sandgren et al, 1996), diatoms (Finkel and Kotrc, 2010), and haptophytes (Yoshida et al, 2006); spines and spicules in radiolarians (Kunitomo et al, 2006), dictyochophytes (Preisig, 1994), centrohelids (Zlatogursky, 2016), and sponges (Weaver et al, 2007); or tablets and scales in haptophytes (Yoshida et al, 2006), rhizarians (Nomura and Ishida, 2016), synurophytes (Sandgren et al, 1996), amoebozoans (Lahr et al, 2013), and brachiopods (Williams et al, 2001). Though the genes governing the production of these silica patterns are not fully understood, many parallels with the molecular biology of diatom silicification are emerging, such as a role for glycoproteins in choanoflagellates (Gong et al, 2010) and synurophytes (Ludwig et al, 1996), cytoskeleton-mediated shaping of the growing silica structure in multiple taxa (Leadbeater, 2015;Nomura and Ishida, 2016) and the presence of post-translationally modified LCPAs in haptophyte (Durak et al, 2016) and sponge (Matsunaga et al, 2007) silica.…”

Section: Cellular and Molecular Aspects Of Evolutionary Competitionmentioning

confidence: 94%

“…This can occur under conditions of extreme silicon limitation, as in the tectiform choanoflagellates or synurophytes which produce naked, but otherwise healthy, cells if starved of silicon (Sandgren et al, 1996;Leadbeater, 2015). It may also be connected to stages in the life cycle, for example in juvenile brachiopods (Williams et al, 2001), or resembling in the haploid/diploid distinction between calcified and uncalcified stages of the E. huxleyi life cycle (Taylor et al, 2017) as has recently been suggested to occur in loricate choanoflagellates (Thomsen and Østergaard, 2017). The capacity for facultative silicification could be a combination of the two, as in the diatom P. tricornutum, unique amongst the diatoms in its ability to survive without a siliceous frustule.…”

Section: Cellular and Molecular Aspects Of Evolutionary Competitionmentioning

confidence: 98%

Competition between Silicifiers and Non-silicifiers in the Past and Present Ocean and Its Evolutionary Impacts

et al. 2018

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Competition is a central part of the evolutionary process, and silicification is no exception: between biomineralized and non-biomineralized organisms, between siliceous and non-siliceous biomineralizing organisms, and between different silicifying groups. Here we discuss evolutionary competition at various scales, and how this has affected biogeochemical cycles of silicon, carbon, and other nutrients. Across geological time we examine how fossils, sediments, and isotopic geochemistry can provide evidence for the emergence and expansion of silica biomineralization in the ocean, and competition between silicifying organisms for silicic acid. Metagenomic data from marine environments can be used to illustrate evolutionary competition between groups of silicifying and non-silicifying marine organisms. Modern ecosystems also provide examples of arms races between silicifiers as predators and prey, and how silicification can be used to provide a competitive advantage for obtaining resources. Through studying the molecular biology of silicifying and non-silicifying species we can relate how they have responded to the competitive interactions that are observed, and how solutions have evolved through convergent evolutionary dynamics.

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The Nature of Siliceous Mosaics Forming the First Shell of the Brachiopod Discinisca

Cited by 29 publications

References 10 publications

Molecular evidence that phoronids are a subtaxon of brachiopods (Brachiopoda: Phoronata) and that genetic divergence of metazoan phyla began long before the early Cambrian

Molecular evidence that phoronids are a subtaxon of brachiopods (Brachiopoda: Phoronata) and that genetic divergence of metazoan phyla began long before the early Cambrian

Lingulate brachiopods from the Acanthopyge Limestone (Eifelian) of the Barrandian, Czech Republic

Competition between Silicifiers and Non-silicifiers in the Past and Present Ocean and Its Evolutionary Impacts

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