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Perotrochus wareni sp. nov., Mnhn-iM-2007-36460, holotype (h = 50.3 mm). A-D. teleoconch. E. slit. F. Protoconch.
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Morphological (shell) and molecular examination of a large suite of specimens of pleurotomariids from around New Caledonia and the Coral Sea reveals the existence of four species in the complex of Perotrochus caledonicus: Perotrochus deforgesi Metivier, 1990 and P. pseudogranulosus sp. nov. live allopatrically on the plateaus and guyots of the Cora...
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Citations
... e.g. Anseeuw et al. , 2015 ;Zhang, Zhang & Wei, 2016 ;Anseeuw, Bell & Harasewych, 2017 ). Over the past several decades, there have been a number of studies investigating the evolutionary relationships among the basal taxa within Gastropoda using anatomical as well as molecular data. ...
... In both trees, five western Pacific species that had been originally described in the genus Perotrochus form another maximally supported clade for which the new genus Bouchetitrochus n. gen. [type species B. pseudogranulosus ( Anseeuw et al. , 2015 )] is here proposed. The remaining pleurotomariids are included in a third well-supported clade (PP = 0.99; BS = 98%) that includes Bayerotrochus midas (Bayer, 1965), the only western Atlantic species, Bayerotrochus africanus (Tomlin, 1848), from the western Indian Ocean, a well-supported clade (PP = 1; BS = 91%) containing four western Pacific species of Bayerotrochus , and a clade comprising three species of Mikadotrochus Lindholm, 1927 (PP = 1; BS = 98%). ...
... Relationships among the genus-level groups in the five-gene tree are less well resolved than those reported in several previously published single gene trees (e.g. Harasewych et al ., 1997 ;Harasewych, 2002 ;Anseeuw et al. , 2015Anseeuw et al. , , 2017Zhang e t al. , 2016 ), although the number of species-level taxa and relationships among them may vary in some instances. Perotrochus pyramus Bayer, 1967, originally described in the genus Perotrochus , had been transferred to Bayerotrochus ( Harasewych, 2002 ) but appears as a member of Perotrochus in our tree. ...
The once diverse family Pleurotomariidae had a widespread global distribution spanning shallow-water faunas throughout the Mesozoic but is presently known only from bathyal habitats along the western margins of the Atlantic and Indo-Pacific Oceans at temperate and tropical latitudes. We evaluate the relationships among surviving lineages of Pleurotomariidae using partial sequences of two mitochondrial genes and three nuclear genes for 22 of the 45 named Recent species-level taxa for which sequence data were available for two or more genes. Phylogenetic analyses partition these species among five lineages, including the new genus Bouchetitrochus n. gen. that is described herein. Of the five lineages, two are present in both the western Atlantic and the western Indo-Pacific Oceans, one is endemic to the western Atlantic and two are endemic to the western Indo-Pacific.
... Pedunculate crinoids (Echinodermata) are additional examples, with 14 genera, of which eight can be considered 'living fossils,' all from New Caledonia (Hess et al., 1999). Known from fossils, many living species of Perotrochus P. Fischer, 1885, gastropods of the family Pleurotomariidae have also been described (Anseeuw et al., 2015). ...
The French carcinologist and oceanographer Alain Crosnier (1930–2021) had a most influential role in modern carcinology. This tribute reviews his contributions to organising oceanographic expeditions; expanding collections of specimens, particularly from the deep sea; and supporting international collaboration for taxonomic investigations of the rich collections of material obtained from these expeditions. His expertise and enthusiasm also extended to the publication of the results of these investigations.
... from Bayerotrochus teramachii and Bayerotrochus sp. Anseeuw et al. (2015) pointed out that the four Perotrochus species from New Caledonia are not convergent with those Perotrochus species from Atlantic, which is confirmed by the present study. ...
... Increasing evidence indicates that allopatric populations are not closely related with each other to a certain extent. For example, the latest molecular study by Anseeuw et al. (2015) shows that the species of Perotrochus from the Pacific are probably not congeneric with Perotrochus species from the Atlantic, and that the Perotrochus caledonicus complex from New Caledonia consists of four distinct species which form three distinct allopatric groups. Similarily, in the present study, the neighbor-joining (NJ) tree shows that the species of Bayerotrochus form two distinct clades (see Fig. 5): Bayerotrochus delicatus sp. ...
A new pleurotomariid species, Bayerotrochus delicatus sp. nov., collected from the Yap Seamount, near Palau, Western Pacific (8°51′N, 137°47′E), is described and illustrated. The generic assignment is based on morphology and molecular evidence. The new species is characterized by a small, depressed trochoid shell sculptured with delicate spiral threads and axial riblets; the shell surface is lustrous orange mottled with iridescence. The radula has a formula of R + 3 + 23 + (ca. 30) + (ca. 65) + 9. These features can separate Bayerotrochus delicatus sp. nov. from its congeners. To determine the relationships of Bayerotrochus delicatus sp. nov. with other pleurotomariids, a neighbor-joining (NJ) tree was established
using available sequences of cytochrome c oxidase I gene (COI) from this study and GenBank.
The use of phylogeny with uneven or limited taxon sampling may bias our interpretation of organismal evolution, for instance, the origin(s) of the deep-sea animals. The Mollusca is the second most speciose phylum, in which the Gastropoda forms the largest group. However, the currently proposed hypotheses of gastropod phylogeny are mainly based on part of their taxonomic diversity, notably on the large-sized and shallow-water species. In this study, we aimed at correcting this bias by reconstructing the phylogeny with new mitogenomes of deep-sea gastropods including Anatoma sp., Bathysciadiidae sp., Bayerotrochus teramachii, Calliotropis micraulax, Coccocrater sp., Cocculina subcompressa, Lepetodrilus guaymasensis, Peltospira smaragdina, Perotrochus caledonicus, Pseudococculinidae sp., and Shinkailepas briandi. This dataset provided the first reports of the mitogenomes for the Cocculiniformia, three vetigastropod superfamilies: Pleurotomarioidea, Lepetelloidea, and Scissurelloidea, and the neritimorph family Phenacolepadidae. The addition of deep-sea representatives also allowed us to evaluate the evolution of habitat use in gastropods. Our results showed a strongly supported sister-group relationship between the deep-sea lineages Cocculiniformia and Neomphalina. Within the Vetigastropoda, the Pleurotomarioidea was revealed as the sister-group of the remaining vetigastropods. Although this clade was presently restricted to the deep sea, fossil records showed that it has only recently invaded this habitat, thus suggesting that shallow waters was the ancestral habitat for the Vetigastropoda. The deep-sea Lepetelloidea and Lepetodriloidea formed a well-supported clade, with the Scissurelloidea sister to it, suggesting an early transition from shallow water to deep sea in this lineage. In addition, the switch between different chemosynthetic habitats was also observed in deep-sea gastropod lineages, notably in Neomphalina and Lepetelloidea. In both cases, the biogenic substrates appeared as the putative ancestral habitat, confirming the previously proposed hypothesis of a wooden-step to deep-sea vents scenario of evolution of habitat use for these taxa.
A new pleurotomariid species, Bayerotrochus belaueiins new species, collected from the Palau Islands, western Pacific, is described and illustrated. This new species is most similar in shell morphology to B. teramachii (Kuroda, 1955), from which it may be distinguished by its thinner, lighter shell with a taller, more stepped spire and lack of pronounced spiral sculpture along the shell base. Molecular data (COI) show B. belauensis new species to be more closely related to B. houcheti from New Caledonia and B. delicatus from Yap, than to B. terarnachii. Bayerotrochus houcheti (Anseeuw and Poppe, 2001) differs in having a broader, more conical spire, a more depressed aperture, and a more darkly pigmented shell with spiral sculpture on the shell base. The recently described B. delicatus S.-P. Zhang, S.Q. Zhang, and Wei, 2016 is easily distinguished by its much smaller size and distinctive shell profile.
