Ćorić, S. ; Galovic, I. ; Matošević, M.
2023 New calcareous nannofossils from the Middle to Late Miocene of the North Croatian Basin, Central Paratethys.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 1-12.
DOI: https://doi.org/10.58998/jnr2059
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
One new genus (Jeremyella) and six new species (Jeremyella levkovii, Cruciplacolithus pavsicii, Reticulofenestra galovicorum, R. benicii, Praenoelaerhabdus galoviciae, Coronosphaera caputiae) of heterococcoliths and two new genera (Nivisolithus and Planolithus) and seven new species (Nivisolithus kovacicii, N. vrabacii, Planolithus mihajlovicii, P. eggeri, Isolithus pavelicii, I. kovacii, Micrantholithus cosoviciae) of nannoliths are described from the Middle to Late Miocene of the Paratethys. Isolithus pavelicii nomen nudum was not validly published previously and has therefore been correctly described herein. Based on the marker species determined in the assemblages, all of the new taxa are from Zones NN6 to NN8.
Howe, R.
2023 Taxonomic note – The status of Sphenolithus strigosus Bown & Dunkley Jones, 2006.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 13-14.
DOI: https://doi.org/10.58998/jnr2125
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
no abstract provided
Young, J. R.
2023 Some proposed changes to the systematics of Cenozoic and Mesozoic nannoplankton.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 15-25.
DOI: https://doi.org/10.58998/jnr2293
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
A series of changes are proposed to the systematics of certain nannoplankton taxa in order to resolve various taxonomic inconsistencies and anomalies. One new Cenozoic species––Calcidiscus thiersteinii––and one new Mesozoic species––Watznaueria leesiae––are proposed, along with 32 new Cenozoic combinations––Coccolithus floralis, Pletolithus hulliae, Reticulofenestra chriskingii, R. nicolasii, R. larae, R. artuziae, Gephyrocapsa maceria, Hornibrookina elegans, Syracosphaera franzii, S. isselii, S. magnaghii, Solisphaera miocaenica, Blackites mericii, B. perfectus, B. prolatus, B. elongatus, B. rothii, B. australensis, Ceratolithus vidalii, Craterolithus hirsutus, C. eolutetiensis, C. plenilutetiensis, Discoaster glenos, D. mexicanus, Lithostromation concavum, L. martinii, L. nodosum, L. hohnensis, L. pyramidale, Peritrachelina arenaria, P. minuta and Martiniaster menneri.
Jiang, S. ; Wang, Y.
2023 Triquetrorhabdulus nanhaiensis, a new early Middle Miocene nannolith species from the South China Sea.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 27-32.
DOI: https://doi.org/10.58998/jnr2129
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
A new calcareous nannofossil species––Triquetrorhabdulus nanhaiensis sp. nov.––was observed during a routine post-cruise biostratigraphic study of the core-catcher and core materials obtained during International Ocean Discovery Program Expedition 368 to the rifted margin of the South China Sea. This large to very large nannolith is an elongate, triradiate, optically monocrystalline rod with the optical c-axis lying parallel to the length of the nannolith. The longitudinal core is enlarged and composed of three laths, with the vertically oriented lath reduced and bisecting the longitudinal core along its length slightly asymmetrically. It has two distinctively long, thin, straight, tapering spines that extend from the enlarged end of the nannolith. These unique spines are oriented nearly perpendicular. Its common abundance and short range of approximately 15.0–15.1 Ma, just below the upper boundary of Zone NN4, provides the potential for an additional datum event as well as for further investigations on the diversification of these nannoliths in the early Middle Miocene.
Lancis, C. ; Tent-Manclús, J. E. ; Flores, J-A.
2023 A new centrifugation/filtration technique to improve the observation of calcareous nannofossils under the scanning electron microscope.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 33-39.
DOI: https://doi.org/10.58998/jnr2157
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
A new sediment sample preparation procedure for observing calcareous nannofossils using a scanning electron microscope (SEM) is described. The new preparation technique is a moderately time-consuming technique that allows observation of the finest structural details of specimens in the SEM. It has two separate steps: 1) disaggregation employing H2O2 and an ultrasound bath, keeping the pH stable through the use of a NaCO3-HCO3 buffer solution; and 2) a filtration process that concentrates and cleans the nannofossils through use of a vacuum pump. To do this, previous techniques for improving the quality of SEM images were combined, aimed at avoiding dissolution in the process, for which a slow digestion of the organic matter was carried out using a buffered solution, adding centrifugation and controlled vacuum pumping in order to retain the coccoliths without affecting their preservation.
Rosario, D. J. G. ; Geronia, M. C. M. ; Peleo-Alampay, A. M. ; Fernando, A. G. S.
2023 Morphometric study and statistical analysis of gephyrocapsids in surface sediments from offshore western Luzon and semi-enclosed bays in the Philippines.
Published in: Journal of Nannoplankton Research, volume 41, part 1, pages 41-54.
DOI: https://doi.org/10.58998/jnr2212
PDF is only available free to INA members for access go to this page. (NB PAYMENT FROM THIS PAGE WILL BE ADDED)Abstract:
The dominance of Gephyrocapsa in the waters and surface sediments of the Philippines makes it ideal for morphological studies. An understanding of the morphology of this genus has been well developed over the years, and an informal nomenclature for specimens from Holocene sediments has been used in several studies. Bollmann (1997) established six categories––equatorial, oligotrophic, transitional, cold, larger and minute forms––based on variations in coccolith length and bridge angle. Each morphotype has been interpreted to have distinct ecological preferences. Results from measurements of placolith length and bridge angle in 1900 Gephyrocapsa coccoliths from surface sediments from offshore western Luzon (eastern South China Sea) and semi-enclosed bays in the Philippines (Lingayen Gulf, Subic Bay, Boac Bay, Calancan Bay) show the occurrence of the oligotrophic, equatorial and larger Gephyrocapsa morphotypes. The oligotrophic morphotype prevails in the majority of the water bodies studied, whereas the larger Gephyrocapsa morphotype manifests mostly in warmer waters. The morphometric results also suggest a separation of the equatorial forms, based on placolith length, into Types GE1 (>3.1 μm) and GE2 (<3.1 μm), with both forms having a bridge angle limit of >61o. A statistical analysis was conducted to confirm the applicability of Bollmann’s morphometric study and the Gephyrocapsa categories to the inland seas and warmer waters of the tropics. Using one-way analysis of variance, it was found that the equatorial and oligotrophic morphotypes were separated at a bridge angle of 61° and not the 56° of Bollmann (1997). The equatorial and larger morphotypes could be differentiated at a placolith length of 3.7 μm instead of the 3.9 μm proposed by Bollmann (1997). This suggests that studies on Gephyrocapsa morphometry from open-ocean samples are not entirely applicable to warmer tropical and inland seas.
