Radiocarbon ages and last occurrences of Globorotalia menardii flexuosa and Globoquadrina hexagona in Atlantic sediment cores

Ranges of Globorotalia menardii menardii, Gr. menardii flexuosa and Globoquadrina hexagona at time of climatostratigraphic intervals representing oxygen-isotope stages 5-1 are determined by study of dozens of Late Quaternary sediment cores involving constructing paleotemperature curves from planktic foraminifera and oxygen isotope curves for their shells, as well as radiocarbon dating. Gr. menardii flexuosa and Gq. hexagona disappeared about 27-25 ky ago from the subtropical and tropical Atlantic and about 18 ky ago from the equatorial area.

(Table 1) Occurrences of Epimeria georgiana species complex (Amphipoda) in the Weddel and Scotia Sea

DNA barcoding revealed four well-supported clades among amphipod specimens that keyed out to Epimeria georgiana Schellenberg, 1931, three clades with specimens from the southern Scotia Arc and one clade with specimens from the Weddell Sea. Detailed morphological investigations of sequenced specimens were conducted, through light and scanning electron microscopy. High magnification (500-2,000 fold) revealed features such as comb-scales on the first antenna and trich bearing pits on the fourth coxal plate to be similar for all specimens in the four clades. Consistent microstructure character differences in the Weddell Sea specimens combined with high genetic distances (COI divergence>20%) allowed the description of Epimeria angelikae, a species new to science. Specimens of E. georgiana in the other three COI clades from the Scotia Arc were morphologically indistinguishable. Representative specimens of clade A are also illustrated in detail. Our results on the high genetic divergences in epimeriid amphipods support the theory of the southern Scotia Arc being a centre of Antarctic diversification.

A dictionary of dates relating to all ages and nations : for universal reference ; comprehending remarkable occurrences, ancient and modern ... /

Includes index.

Reconnaissance of uranium occurrences at Wray Mesa, San Juan County, Utah and Montrose County, Colorado /

"RME-69(Pt. 1)."

Uranium occurrences in Wilson Creek area, Gila County, Arizona /

"July 1954."

Uranium occurrences in the Mojave mining district, Kern County, California /

"February 1957."

Some uranium occurrences in northern Ferry County, Washington /

"October 1958."

Selected bibliography on radioactive occurrences in the United States /

"May 1970."

Diary of occurrences on a journey through a part of Belgium, Holland, and up the Rhine to Mayence, and thence to Paris in the months of August and September 1828.

Mode of access: Internet.

A curtail'd memoir of incidents and occurrences in the life of John Surman Carden, vice admiral in the British navy.

Mode of access: Internet.