| 1. |
- Amano, Kazutaka, et al.
(författare)
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Bivalvia in ancient hydrocarbon seeps
- 2022
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Ingår i: Ancient Hydrocarbon Seeps. - Berlin : Springer Berlin/Heidelberg. ; , s. 267-321
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Bokkapitel (refereegranskat)abstract
- Bivalves are an important part of the methane seep fauna ever since seeps appeared in the geologic record. The chronostratigraphic ranges of seep-inhabiting chemosymbiotic bivalves show an overall increase in diversity at seeps since the Paleozoic. The most common group at Paleozoic and early Mesozoic seeps are modiomorphids, with a few additional records of solemyids and anomalodesmatans. The most common infaunal chemosymbiotic bivalve taxa at modern seeps, lucinids and thyasirids, appeared at seeps in the Late Jurassic and earliest Cretaceous. They diversified during the Cretaceous synchronous with the peak of the “Mesozoic Marine Revolution” and first occurrences of gastropod predatory drill holes in the shells of seep-inhabiting bivalves, soon after the appearance of these gastropods in the mid-Cretaceous. The two dominant bivalve clades of the modern vent and seep fauna, bathymodiolins and vesicomyids, appeared in the Eocene. Their origin has been linked to a deep-water extinction event at the Paleocene-Eocene Thermal Maximum. However, the fossil record of chemosymbiotic bivalves at seeps during this time interval does not display any extinction. Rather, the mid-Eocene appearance of semi-infaunal and epifaunal bivalves such as bathymodiolins and vesicomyids might be linked to a dramatic rise in seawater sulfate concentrations at this time.
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| 2. |
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| 3. |
- Ceballos, Yasmani, et al.
(författare)
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Corals and mollusks from a Miocene carbonate-rich deposit of Madruga, western Cuba
- 2021
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Ingår i: Poeyana. - Havana : Cuban Academy of Sciences. - 2410-7492. ; 512, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Here is reported fauna from a Middle Miocene limestone deposit of the Cojímar Formation near the town of Aguacate in the Province of Mayabeque, western Cuba. The fossils are preserved only as internal or external molds, but we identified members of at least eight bivalves and six gastropod families and one solitary coral. The most common taxon is a lucinid bivalve probably belonging to the genus Anodontia, which may likely represent a new taxon. This species in particular, and the fauna and facies in general, suggest that the Aguacate limestone may represent an ancient seagrass meadow environment. The fauna of the Aguacate quarry shows biogeographic relationships mainly to the Miocene of Panama and Florida, but also some links to the subtropical Atlantic coast of North America, and the Miocene of northern Ecuador.
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| 6. |
- Goedert, James L., et al.
(författare)
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Miocene Nautilus (Mollusca, Cephalopoda) from Taiwan, and a review of the Indo‐Pacific fossil record of Nautilus
- 2022
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Ingår i: Island Arc. - Hoboken : John Wiley & Sons. - 1038-4871 .- 1440-1738. ; 31:1
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Tidskriftsartikel (refereegranskat)abstract
- The fossil record of the cephalopod genus Nautilus has been obscured because a few influential taxonomists during the 20th Century decided that fossils similar to Nautilus were instead other genera. We now recognize fossils once classified as species of other genera as species of Nautilus. This includes fossils from Miocene rocks of Taiwan that were previously described as Kummelonautilus taiwanum but herein recognized instead as being the northernmost Neogene record of Nautilus in the Indo-Pacific region. The name is corrected to Nautilus taiwanus, and now known to occur in two formations in central Taiwan, the early Miocene Shihmentsun and early to middle Miocene Houdongkeng formations. Miocene fossils from Indonesia that were placed in other genera are now considered to represent Nautilus as they were originally assigned, in addition to several Miocene species from Australia, which provide the southernmost Neogene fossil record for the genus. Some of these Indo-Pacific fossils may represent the same species, but more specimens are needed to determine the amount of variability within these Neogene taxa.
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| 7. |
- Goedert, James L., et al.
(författare)
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Octocorals (Alcyonacea and Pennatulacea) from Paleogene deep-water strata in western Washington State, USA
- 2022
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Ingår i: Journal of Paleontology. - Washington DC : Paleontological Society (United States). - 0022-3360 .- 1937-2337. ; 96:3, s. 539-551
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Tidskriftsartikel (refereegranskat)abstract
- The fossil record of octocorals from Cenozoic marine strata of western North America is quite limited, and they have not been reported previously from rocks in Washington State, USA. Two late Oligocene specimens from the upper part of the Lincoln Creek Formation in western Washington, referred to Radicipes? sp., are the first fossil record of the family Chrysogorgiidae. The family Isididae is represented by an internode and two holdfasts identified as Isidella sp. collected from the Oligocene Pysht Formation, along with specimens questionably identified as Lepidisis sp., possibly the first fossil record for this genus. Together, these are the first confirmed fossils of the Alcyonacea from north of California in western North America. The axes of sea pens from several late Eocene or early Oligocene localities in the Lincoln Creek Formation in the central part of western Washington, and the Pysht and Makah formations on the north side of the Olympic Peninsula, are the first fossil record for the Pennatulacea from western North America; all are tentatively referred to the genus ‘Graphularia’. Large axes from the Lincoln Creek Formation and Makah Formation are referred to ‘Graphularia’ (?) aff. sasai, because they are similar to the species known only from late Eocene and early Oligocene rocks in Japan.
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| 8. |
- Guan, Hongxiang, et al.
(författare)
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Lipid Biomarker Patterns Reflect Nutritional Strategies of Seep-Dwelling Bivalves From the South China Sea
- 2022
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Ingår i: Frontiers in Marine Science. - Lausanne : Frontiers Media. - 2296-7745. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Invertebrates living at methane seeps such as mussels and clams gain nutrition through symbiosis with chemosynthetic, chiefly methanotrophic and thiotrophic bacteria. Lipid biomarkers, including their compound-specific carbon stable isotope compositions, extracted from the host tissues are predestined for deciphering the various sources of diets and the associations among varying environments, endosymbionts, and hosts. Here, we investigated lipid inventories of soft tissues of two bathymodiolin mussel species hosting aerobic methanotrophic bacteria (Gigantidas platifrons from Site F and Gigantidas haimaensis from Haima seeps), one bathymodiolin mussel with thiotrophic bacteria (Bathymodiolus aduloides from Haima seeps), and one vesicomyid clam (Archivesica marissinica from Haima seeps) from the South China Sea. The gills of mussels hosting methanotrophic symbionts were found to contain high amounts of lipids of aerobic methanotrophic bacteria, such as the 4,4-dimethyl lanosterol, and other 4-methyl sterols, and the type I methanotroph-specific monounsaturated fatty acids (MUFAs) C16:1ω9 and C16:1ω8. Production of methyl-sterols is favored over fatty acids at low oxygen concentrations, as demonstrated in culture experiments with Methylococcus capsulatus. Since lesser fatty acids and abundant sterols are found in G. haimaensis compared to G. platifrons, G. haimaensis apparently lived at very low oxygen levels. Extremely high levels of MUFAs C16:1ω7 and C18:1ω7 were found in gill tissue of both B. aduloides and the vesicomyid clam A. marissinica. Given the absence of ω8 fatty acids, both B. aduloides and the vesicomyid clam contain thiotrophic bacteria only. The occurrence of 13C-enriched 24-methylenecholesterol in B. aduloides indicates that the animal complemented its diet by filter-feeding (ca. 3% of the total sterol inventory) on photosynthetically derived carbon, whereas the majority of sterols are pointing to a diet relying on endosymbionts. Different types of 4-methyl sterols were observed between the thiotroph-containing mussel and methanotroph-containing mussels, suggesting different biosynthetic steps are present from lanosterol to cholesterol between animal hosts and aerobic methanotrophs. Among the four bivalve species, specific lipid biomarker patterns diagnostic for either the symbionts or the hosts yielded similar δ13C values in each species, indicating that the host obtained its nutrition either directly from the symbionts or derived at least most of its carbon in this way. The information derived from lipid biomarkers of bivalves and their corresponding symbionts in modern environments is vital to interpret data from the rock record, where most other methods to study microbial community composition are not applicable.
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| 10. |
- Hryniewicz, Krzysztof, et al.
(författare)
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Thyasirid bivalves from Cretaceous and Paleogene cold seeps
- 2017
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Ingår i: Acta Palaeontologica Polonica. - Warsaw : Instytut Paleobiologii PAN. - 0567-7920 .- 1732-2421. ; 62:4, s. 705-728
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Tidskriftsartikel (refereegranskat)abstract
- We present a systematic study of thyasirid bivalves from Cretaceous to Oligocene seep carbonates worldwide. Eleven species of thyasirid bivalves are identified belonging to three genera: Conchocele, Maorithyas, and Thyasira. Two species are new: Maorithyas humptulipsensis sp. nov. from middle Eocene seep carbonates in the Humptulips Formation, Washington State, USA, and Conchocele kiritachiensis sp. nov. from the late Eocene seep deposit at Kiritachi, Hokkaido, Japan. Two new combinations are provided: Conchocele townsendi (White, 1890) from Maastrichtian strata of the James Ross Basin, Antarctica, and Maorithyas folgeri (Wagner and Schilling, 1923) from Oligocene rocks from California, USA. Three species are left in open nomenclature. We show that thyasirids have Mesozoic origins and appear at seeps before appearing in “normal” marine environments. These data are interpreted as a record of seep origination of thyasirids, and their subsequent dispersal to non-seep environments. We discuss the age of origination of thyasirids in the context of the origin of the modern deep sea fauna and conclude that thyasirids could have deep sea origins. This hypothesis is supported by the observed lack of influence of the Cretaceous and Paleogene Oceanic Anoxic Events on the main evolutionary lineages of the thyasirids, as seen in several other members of the deep sea fauna.
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