En savoir plus ...Site officiel : http://www.laplaneterevisitee.org/fr
Patriat M., Collot J., Etienne S., Poli S., Clerc C., Mortimer N., Pattier F., Juan C., Roest W.R. & Vespa scientific voyage team 2018. New Caledonia Obducted Peridotite Nappe: Offshore Extent and Implications for Obduction and Postobduction Processes. Tectonics 37(4): 1077-1096. DOI:10.1002/2017TC004722
Résumé [+] [-]One of the largest ophiolitic peridotite masses in the world covers a quarter of the island of Grande Terre, New Caledonia. The Peridotite Nappe was obducted during the Eocene, is weakly deformed, and corresponds to the highest of a structurally simple pile of thrust nappes. We present new marine seismic data that allow us to track the offshore continuation of the Peridotite Nappe along strike for a distance of more than 500 km south of New Caledonia and to image its preobduction, synobduction, and postobduction sedimentary records. Offshore, the Peridotite Nappe underlies a ~150 km wide and 2 km deep basin. Flat-topped horsts of peridotite are clearly bounded by major normal faults; in contrast, faults are obscure onland. To the east, the Peridotite Nappe roots along the eastern margin of the Félicité Ridge (new name), a ~300 × 25 km dome-shaped ridge, which we interpret as being the southern extension of the high-pressure/ low-temperature metamorphic core complex observed in New Caledonia. Two alternative tectonic models address the relative timing and relationships between Peridotite Nappe emplacement, uplift of a metamorphic core complex, and extensional tectonics. These models provide new ideas for the understanding the formation of the eastern margin of the Zealandia continent. Our results contribute to an understanding of how oceanic mantle is emplaced onto continental margins.
Campagnes accessibles citées (1) [+] [-]
Tongboonkua P., Lee M.Y. & Chen W.J. 2018. A new species of sinistral flatfish of the genus Chascanopsetta (Teleostei: Bothidae) from off Papua New Guinea, western Pacific Ocean. Zootaxa 4476(1): 168. DOI:10.11646/zootaxa.4476.1.16
Résumé [+] [-]Left-eyed flounders of the genus Chascanopsetta Alcock 1894 (Bothidae) occur in the Indian, Pacific, and Atlantic oceans at depths ranging from 120 to 1500 meters. They possess some unique features in bothid fishes including a strongly compressed and elongated body and a tremendously large mouth. Currently, nine species of Chascanopsetta are recognized, and three of them (C. micrognatha Amaoka & Yamamoto 1984, C. lugubris Alcock 1894 and C. prognatha Norman 1939) are distributed in the West Pacific. We collected 25 specimens of Chascanopsetta during 11 biodiversity expeditions carried out mainly in the West Pacific. Among them, eight specimens taken off Papua New Guinea present morphological features that differ from those of the three nominal species known in the West Pacific. In this study, we examined these eight specimens of unknown affinity and compared their morphology to that of specimens of other congeneric species. Results of these comparisons showed that these specimens represent an undescribed species of Chascanopsetta, named herein, C. novaeguineae sp. nov.. The new species resembles C. elski Foroshchuk 1991, which is known only from the Saya de Malha Bank in the western Indian Ocean, in having a high number of gill rakers (> 13). However, the combination of the following characters further distinguishes C. novaeguineae sp. nov. from C. elski: longer jaws, narrower interorbital width, and number of pseudobranches (21–25 vs. 26–27). The DNA sequences from the mitochondrial cytochrome oxidase subunit I (COI) gene from C. novaeguineae sp. nov. and other species were obtained and compared to confirm its taxonomic status and to infer its tentative phylogenetic position within the Chascanopsetta.
Campagnes accessibles citées (11) [+] [-]
Kantor Y.I., Fedosov A.E., Snyder M.A. & Bouchet P. 2018. Pseudolatirus Bellardi, 1884 revisited, with the description of two new genera and five new species (Neogastropoda: Fasciolariidae). European Journal of Taxonomy 433: 1-57. DOI:10.5852/ejt.2018.433
Résumé [+] [-]The genus Pseudolatirus Bellardi, 1884, with the Miocene type species Fusus bilineatus Hörnes, 1853, has been used for 13 Miocene to Early Pleistocene fossil species and eight Recent species and has traditionally been placed in the fasciolariid subfamily Peristerniinae Tryon, 1880. Although the fossil species are apparently peristerniines, the Recent species were in their majority suspected to be most closely related to Granulifusus Kuroda & Habe, 1954 in the subfamily Fusininae Wrigley, 1927. Their close affinity was confirmed by the molecular phylogenetic analysis of Couto et al. (2016). In the molecular phylogenetic section we present a more detailed analysis of the relationships of 10 Recent Pseudolatirus-like species, erect two new fusinine genera, Okutanius gen. nov. (type species Fusolatirus kuroseanus Okutani, 1975) and Vermeijius gen. nov. (type species Pseudolatirus pallidus Kuroda & Habe, 1961). Five species are described as new for science, three of them are based on sequenced specimens (Granulifusus annae sp. nov., G. norfolkensis sp. nov., Okutanius ellenae gen. et sp. nov.) and two (G. tatianae sp. nov., G. guidoi sp. nov.) are attributed to Granulifusus on the basis of conchological similarities to sequenced species. New data on radular morphology is presented for examined species.
Campagnes accessibles citées (20) [+] [-]