Re-discovery of a "living fossil" coccolithophore from the coastal waters of Japan and Croatia

The extant coccolithophore Tergestiella adriatica Kamptner, which had not been reported since its original description in 1940, was recently re-discovered in coastal-nearshore waters at Tomari, Tottori (Japan) and offshore Rovinj (Croatia). Morphological analysis shows that extant Tergestiella and the Mesozoic genus Cyclagelosphaera (Watznaueriaceae), thought to have been extinct since the early Eocene (~. 54. Ma), are virtually identical. Molecular phylogenetic study supports the inference that T. adriatica is a direct descendent of Cyclagelosphaera. It is therefore a remarkable example of a living fossil. Our documentation of patchy coastal distribution in living T. adriatica and records of rare occurrences of fossil Cyclagelosphaera in Oligocene-Miocene shallow water sediments. , from the New Jersey shelf, suggest that Tergestiella/. Cyclagelosphaera was restricted to nearshore environments during much of the Cenozoic. This restricted ecology explains the lack of fossil Tergestiella/. Cyclagelosphaera recorded in open ocean sediments deposited during the last 54. myr.Floristic study of coccolithophores in the coastal and offshore waters of Tomari over a six-year period, show that T. adriatica occurs synchronously with the unusual neritic species, Braarudosphaera bigelowii, in mid-June. The environmental factors that induce the co-occurrence of these two taxa are uncertain, and T. adriatica did not co-occur with B. bigelowii at any other sites

Data report: composite depth scale and splice revision for IODP Site U1488 (Expedition 363 Western Pacific Warm Pool) using XRF core scanning data and core images

The Western Pacific Warm Pool (WPWP) is a major source of heat and moisture to the atmosphere. Small perturbations in WPWP sea-surface temperatures greatly influence local Hadley and Walker cells, thereby affecting global atmospheric circulation patterns. International Ocean Discovery Program (IODP) Expedition 363 sought to document the regional expression and driving mechanisms of WPWP climate variability during the Neogene on millennial, orbital, and geological timescales. Located in the heart of the WPWP, IODP Site U1488 (02°02.59ʹN, 141°45.29ʹE) was drilled in 2604 m water depth on the southern part of the Eauripik Rise in the Caroline Basin. At Site U1488, a continuous shipboard composite stratigraphic section from 0 to ~331 m core composite depth below seafloor (CCSF) was compiled using high-resolution shipboard physical property data from three holes. This section comprises upper Miocene to recent foraminifer-rich nannofossil ooze and foraminifer-nannofossil ooze, making Site U1488 ideally suited to reconstruct the paleoceanographic history of the central WPWP region. However, the high carbonate content (>90% below ~180 m CCSF) of Site U1488 sediments means that the physical property data sets commonly used for splice construction (gamma ray attenuation bulk density, magnetic susceptibility, and natural gamma radiation) were too low amplitude to provide robust constraints on splice tie points below 120 m CCSF. As a result, P-wave data, which are relatively untested as a correlation tool, became critical for correlating between holes. Here, we verify and extend the Site U1488 shipboard composite splice using high-resolution (2 cm) X-ray fluorescence Ba/Sr core scanning data combined with composite linescan images. Overall, using these data at Site U1488 resulted in revised core offsets that differ by up to 0.84 m relative to the shipboard core offsets and a composite depth scale down to 329.33 m revised CCSF. The revised splice will allow optimization of postexpedition research and ensure that high-resolution studies of Site U1488 are conducted on a continuous stratigraphic section