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Julia D Sigwart - One of the best experts on this subject based on the ideXlab platform.
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how the mollusc got its scales convergent evolution of the molluscan scleritome
Biological Journal of The Linnean Society, 2015Co-Authors: Chong Chen, Katrin Linse, J Copley, Alex Rogers, Julia D SigwartAbstract:Radiation of dramatically disparate forms among the phylum Mollusca remains a key question in metazoan evolution, and requires careful evaluation of homology of hard parts throughout the deep fossil record. Enigmatic early Cambrian taxa such as Halkieria and Wiwaxia (in the clade Halwaxiida) have been proposed to represent stem-group aculiferan molluscs (Caudofoveata?+?Solenogastres?+?Polyplacophora), as complex scleritomes were considered to be unique to aculiferans among extant molluscs. The ‘scaly-foot gastropod’ (Neomphalina: Peltospiridae) from hydrothermal vents of the Indian Ocean, however, also carries dermal sclerites and thus challenges this inferred homology. Despite superficial similarities to various mollusc sclerites, the scaly-foot gastropod sclerites are secreted in layers covering outpockets of epithelium and are largely proteinaceous, while chiton (Polyplacophora: Chitonida) sclerites are secreted to fill an invaginated cuticular chamber and are largely calcareous. Marked differences in the underlying epithelium of the scaly-foot gastropod sclerites and operculum suggest that the sclerites do not originate from multiplication of the operculum. This convergence in different classes highlights the ability of molluscs to adapt mineralized dermal structures, as supported by the extensive early fossil record of molluscs with scleritomes. Sclerites of halwaxiids are morphologically variable, undermining the assumed affinity of specific taxa with chitons, or the larger putative clade Aculifera. Comparisons with independently derived similar structures in living molluscs are essential for determining homology among fossils and their position with respect to the enigmatic evolution of molluscan shell forms in deep time.
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chiton phylogeny mollusca Polyplacophora and the placement of the enigmatic species choriplax grayi h adams angas
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
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new records for the shallow water chiton fauna mollusca Polyplacophora of the azores ne atlantic
ZooKeys, 2013Co-Authors: Sérgio P. Ávila, Julia D SigwartAbstract:Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic), and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA) were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species.
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Chiton phylogeny (Mollusca Polyplacophora) and the placement of the enigmatic species Choriplax grayi (H. Adams & Angas)
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
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Variation in oxygen consumption among 'living fossils' (Mollusca: Polyplacophora)
Journal of the Marine Biological Association of the United Kingdom, 2012Co-Authors: Nicholas Carey, Alexander Galkin, Patrik J. G. Henriksson, Jeffrey G. Richards, Julia D SigwartAbstract:Polyplacophoran molluscs (chitons) are phylogenetically ancient and morphologically constrained, yet multiple living species are often found co-occurring within widely overlapping ecological niches. This study used two sets of experiments to compare interspecific variation among co-occurring species in the North Atlantic (Ireland) and separately in the North Pacific (British Columbia, Canada) chiton faunas. A complementary review of historical literature on Polyplacophoran physiology provides an overview of the high level of metabolic variability in this group of ‘living fossils’. Species examined in de novo experiments showed significant variation in oxygen consumption both under air-saturated water conditions (normoxia), and in response to decreasing oxygen availability (hypoxia). Some species demonstrate an ability to maintain constant oxygen uptake rates despite hypoxia (oxyregulators), while others oxyconform, with uptake rate dependent on ambient oxygen tension. These organisms are often amalgamated in studies of benthic communities, yet show obvious physiological difference that may impact their response or tolerance to environmental change.
Enrico Schwabe - One of the best experts on this subject based on the ideXlab platform.
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Eocene and Oligocene chitons (Polyplacophora) from the Paris and Hampshire Basins
Historical Biology, 2017Co-Authors: Lesley Cherns, Enrico SchwabeAbstract:Eocene and Oligocene chitons (Polyplacophora) from the Paris Basin of N France are described along with comparative material from the Hampshire Basin of the UK. The assemblages include eight species, five of which are new: Ischnochiton fehsei sp. nov., Stenoplax monila sp. nov., Chaetopleura gaasi sp. nov., C. abbessi sp. nov. and Tonicella lira sp. nov. Other taxa in the assemblages are Leptochiton cf. algesirensis, I. vectensis and S. anglica.
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urn:lsid:zoobank.org:pub:B5CAA0D6-6F90-4311-899F-210544BFDCFF Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands
2016Co-Authors: Enrico Schwabe, Ro Gori, Maurizio Sosso, Antonio BonfittoAbstract:The chiton fauna of São Tomé and Príncipe Islands is poorly known and here we present the first comprehensive and illustrated account of living Polyplacophora from these islands. Four species have bee
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Just undiscovered or invasive? The first record of a chiton (Mollusca: Polyplacophora) from the remote Ascension Island, southern Atlantic Ocean
Journal of the Marine Biological Association of the United Kingdom, 2014Co-Authors: Enrico Schwabe, Konstantinos TsiamisAbstract:During a recent expedition to Ascension Island in the southern Atlantic Ocean, a Polyplacophoran of the genus Acanthochitona was collected, corresponding to the first recorded species of this molluscan class from this remote island. A scanning electron microscope study reveals a close affinity to Acanthochitona subrubicunda , which was so far only known from the Cape Verde Archipelago. Due to the lack of comparable type material the new finding warrants a confirmed identification and is only tentatively attributed to Acanthochitona subrubicunda . It is hypothesized that the class Polyplacophora was either overlooked during earlier surveys or colonized the island in more recent time. If the latter scenario took place, a transport by ships is thinkable.
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chiton phylogeny mollusca Polyplacophora and the placement of the enigmatic species choriplax grayi h adams angas
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
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Chiton phylogeny (Mollusca Polyplacophora) and the placement of the enigmatic species Choriplax grayi (H. Adams & Angas)
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
Bilal Öztürk - One of the best experts on this subject based on the ideXlab platform.
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Polyplacophora and Gastropoda species distributed on the hard subtratum in the Antalya Gulf and its vicinity
Ege Journal of Fisheries and Aquatic Sciences, 2016Co-Authors: Banu Bitlis Bakır, Bilal ÖztürkAbstract:Bu calisma, Turkiye’nin Levant Denizi kiyilarinda yer alan Antalya Korfezi ve civarinda dagilim gosteren Polyplacophora ve Gastropoda turlerini tespit etmek icin gerceklestirilmistir. Incelenen bentik materyal, kuadrat ornekleme yontemiyle supralittoral ve mediolittoral zonlarin derinliklerinde yer alan kayalik, kirmizi alg ve kahverengi alglerden olusan biyotop yapisina sahip, 14 farkli istasyondan alinmistir. Elde edilen materyalin incelenmesi sonucunda Polyplacophora ve Gastropoda siniflarina ait 23 familya ve bunlara ait toplam 43 tur tespit edilmistir. Bu turlerden Cerithium scabridum, Sticteulima lentiginosa, Conomurex persicus ve Ergalatax junionae Akdeniz’e cesitli yollarla giris yapan yabanci turler olup , Cerithium vulgatum ve Dendropoma petraeum ise nesli tehlike altinda olan turlerdir. Bunun yaninda, Cerithium scabridum , Bittium latreilli ve Columbella rustica bolgede yaygin dagilimi olan turlerdir. Birey sayisi bakimindan Eatonina pumila, Cerithium scabridum ve Bittium latreilli en dominant turlerdir.
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Polyplacophora and Gastropoda species distributed on the hard subtratum in the Antalya Gulf and its vicinity
2016Co-Authors: Banu Bakır Bitlis, Bilal ÖztürkAbstract:Bu çalışma, Türkiye'nin Levant Denizi kıyılarında yer alan Antalya Körfezi ve civarında dağılım gösteren Polyplacophora ve Gastropoda türlerini tespit etmek için gerçekleştirilmiştir. İncelenen bentik materyal, kuadrat örnekleme yöntemiyle supralittoral ve mediolittoral zonların derinliklerinde yer alan kayalık, kırmızı alg ve kahverengi alglerden oluşan biyotop yapısına sahip, 14 farklı istasyondan alınmıştır. Elde edilen materyalin incelenmesi sonucunda Polyplacophora ve Gastropoda sınıflarına ait 23 familya ve bunlara ait toplam 43 tür tespit edilmiştir. Bu türlerden Cerithium scabridum, Sticteulima lentiginosa, Conomurex persicus ve Ergalatax junionae Akdeniz'e çeşitli yollarla giriş yapan yabancı türler olup, Cerithium vulgatum ve Dendropoma petraeum ise nesli tehlike altında olan türlerdir. Bunun yanında, Cerithium scabridum, Bittium latreilli ve Columbella rustica bölgede yaygın dağılımı olan türlerdir. Birey sayısı bakımından Eatonina pumila, Cerithium scabridum ve Bittium latreilli en dominant türlerdir.This study was carried out in order to determine the Polyplacophora and Gastropoda species distributed in the Gulf of Antalya and its vicinity located on the Turkish Levantine coast. The investigated benthic material was collected from various biotopes i. e., rocks, red and brown algae at 14 different stations of supralittoral and mediolittoral depths by using a quadrat frame. As a result of the examination of the collected material, a total of 43 species and 23 families belonging to the classes Polyplacophora and Gastropoda were determined. Among the identified species, Cerithium scabridum, Sticteulima lentiginosa, Conomurex persicus and Ergalatax junionae are alien species entered to the Mediterranean Sea by different pathways, whereas Cerithium vulgatum and Dendropoma petraeum are endangered species. At the same time, Cerithium scabridum, Bittium latreilli and Columbella rustica are distributed commonly in the region. Eatonina pumila, C. scabridum and Bittium latreilli are also the dominant species of the area
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Antalya Körfezi ve civarındaki sert substratumda dağılım gösteren Polyplacophora ve Gastropoda türleri
Ege University, 2016Co-Authors: Banu Bitlis Bakır, Bilal ÖztürkAbstract:Bu çalışma, Türkiye’nin Levant Denizi kıyılarında yer alan Antalya Körfezi ve civarında dağılım gösteren Polyplacophora ve Gastropoda türlerini tespit etmek için gerçekleştirilmiştir. İncelenen bentik materyal, kuadrat örnekleme yöntemiyle supralittoral ve mediolittoral zonların derinliklerinde yer alan kayalık, kırmızı alg ve kahverengi alglerden oluşan biyotop yapısına sahip, 14 farklı istasyondan alınmıştır. Elde edilen materyalin incelenmesi sonucunda Polyplacophora ve Gastropoda sınıflarına ait 23 familya ve bunlara ait toplam 43 tür tespit edilmiştir. Bu türlerden Cerithium scabridum, Sticteulima lentiginosa, Conomurex persicus ve Ergalatax junionae Akdeniz’e çeşitli yollarla giriş yapan yabancı türler olup, Cerithium vulgatum ve Dendropoma petraeum ise nesli tehlike altında olan türlerdir. Bunun yanında, Cerithium scabridum, Bittium latreilli ve Columbella rustica bölgede yaygın dağılımı olan türlerdir. Birey sayısı bakımından Eatonina pumila, Cerithium scabridum ve Bittium latreilli en dominant türlerdir
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Marine molluscs of the Turkish coasts: an updated checklist
TURKISH JOURNAL OF ZOOLOGY, 2014Co-Authors: Bilal Öztürk, Alper Doğan, Banu Bitlis-bakir, Alp SalmanAbstract:This study presents the molluscan species diversity along the Turkish coasts. The compilation of the available references revealed a total of 1065 species belonging to 7 classes (Caudofoveata, Solenogastres, Polyplacophora, Gastropoda, Bivalvia, Scaphopoda, and Cephalopoda). Most of the reported species belong to the class Gastropoda (706 species), followed by Bivalvia (279 species), Cephalopoda (50 species), Polyplacophora (17 species), Scaphopoda (10 species), Caudofoveata (2 species), and Solenogastres (1 species). Among the coasts of Turkey, the highest number of molluscan species was recorded from the Aegean Sea (825 species), followed by the Levantine Sea (807 species), Sea of Marmara (537 species), and the Black Sea (155 species). Of the 1065 mollusc taxa, 118 species are alien ones that originated outside the Mediterranean Sea. Among the listed species, Timoclea roemeriana (Bivalvia), and Sepiola ligulata and Abraliopsis morisii (both from Cephalopoda) are new records for the Turkish mollusc fauna, 11 species of the classes Polyplacophora, Gastropoda, and Bivalvia (Leptochiton boettgeri, Cerithium protractum, Similiphora similior, Cerithiopsis diadema, Rissoa guerinii, Crepidula moulinsii, Crepidula unguiformis, Bela zenetouae, Doto coronata, Lima marioni, and Limaria loscombi) are new reports for the Levantine coast of Turkey, and 2 gastropod species (Acirsa subdecussata and Monotygma lauta) are new reports for the Aegean coast of Turkey. Among the listed taxa, 27 species have been classified in the IUCN Red List or Barcelona/Bern Conventions.
Rudolf Kilias - One of the best experts on this subject based on the ideXlab platform.
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Polyplacophora‐Typen und ‐Typoide (Mollusca) im Zoologischen Museum in Berlin
Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin), 1995Co-Authors: Rudolf KiliasAbstract:Catalogue of the Types of Polyplacophora (Mollusca) in the Collections of the Zoological Museum in Berlin This paper registers the type specimens of Polyplacophora (Mollusca) in the collections of the Zoological Museum in Berlin. It includes hundred-one types of species, described by Edwin Ashby, W. T. Bednall, William Healey Dall, Frederic Wollaston Huttton, Tom Iredale, Hugo Frederic Nierstrasz, Georg Pfeffer, Henry Augustus Pilsbry, Ludwig Plate, Jean Rene Constantin Quoy & J. P. Gaimard, Alphonse Tremeau de Rochebrune, George Ossian Sars, Leopold von Schrenck, Henry Suter, Johannes Thiele, Kurt von Wissel. Collection and bibliographical data are provided for the specimens.
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Polyplacophora typen und typoide mollusca im zoologischen museum in berlin
Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin), 1995Co-Authors: Rudolf KiliasAbstract:Catalogue of the Types of Polyplacophora (Mollusca) in the Collections of the Zoological Museum in Berlin This paper registers the type specimens of Polyplacophora (Mollusca) in the collections of the Zoological Museum in Berlin. It includes hundred-one types of species, described by Edwin Ashby, W. T. Bednall, William Healey Dall, Frederic Wollaston Huttton, Tom Iredale, Hugo Frederic Nierstrasz, Georg Pfeffer, Henry Augustus Pilsbry, Ludwig Plate, Jean Rene Constantin Quoy & J. P. Gaimard, Alphonse Tremeau de Rochebrune, George Ossian Sars, Leopold von Schrenck, Henry Suter, Johannes Thiele, Kurt von Wissel. Collection and bibliographical data are provided for the specimens.
Thomas Knebelsberger - One of the best experts on this subject based on the ideXlab platform.
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chiton phylogeny mollusca Polyplacophora and the placement of the enigmatic species choriplax grayi h adams angas
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
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Chiton phylogeny (Mollusca Polyplacophora) and the placement of the enigmatic species Choriplax grayi (H. Adams & Angas)
Invertebrate Systematics, 2013Co-Authors: Julia D Sigwart, Isabella Stoeger, Thomas Knebelsberger, Enrico SchwabeAbstract:Shallow marine chitons (Mollusca : Polyplacophora : Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of Polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.
