Paleobiogeographic affinities of Emsian (late Early Devonian) gastropods from Farewell terrane (west-central Alaska)

2008 ◽  
Author(s):  
Jiří Frýda ◽  
Robert B. Blodgett
Keyword(s):  
Early Devonian ◽  
West Central

Two new Devonian spine-bearing pleurotomariacean gastropod genera from Alaska

1989 ◽  
Vol 63 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Robert B. Blodgett ◽  
David M. Rohr
Keyword(s):  
Middle Devonian ◽  
New Genera ◽  
Early Devonian ◽  
Old World ◽  
West Central ◽  
Cool Temperate ◽  
Warm Temperate

Two new spine-bearing gastropods, Chlupacispira spinosa n. gen. and sp. and Spinulrichospira cheeneetnukensis n. gen. and sp., are described from the late Early Devonian (Emsian) and early Middle Devonian (Eifelian), respectively, of west-central Alaska. These represent the earliest reported spiny pleurotomariacean gastropods. Otherwise, spinose pleurotomariaceans are known from strata no older than Carboniferous age. Spinulrichospira cheeneetnukensis n. gen. and sp. appears to represent a more highly ornamented derivative of Ulrichospira Donald. Both new genera are part of the more highly ornamented fauna which occurred in warm equatorial waters of the Old World Realm during the Early and Middle Devonian, in contrast to more weakly ornamented shells of the Eastern Americas Realm and even more weakly ornamented (almost totally “plain”) shells of the Malvinokaffric Realm. The latter two realms are thought to represent subtropical to warm temperate and cool temperate to cool polar conditions, respectively.

Late Silurian-Early Devonian slab break-off beneath the Canadian Appalachians: Insights from the Nashwaak Granite, west-central New Brunswick, Canada

Lithos ◽  
2020 ◽  
Vol 358-359 ◽  
pp. 105393 ◽  
Author(s):  
Wei Zhang ◽  
David R. Lentz ◽  
Kathleen G. Thorne ◽  
Ronald J.R. Massawe
Keyword(s):  
New Brunswick ◽  
Early Devonian ◽  
West Central ◽  
Canadian Appalachians

Two new cirroidean genera (Vetigastropoda, Archaeogastropoda) from the Emsian (Late Early Devonian) of Alaska with notes on the early phylogeny of Cirroidea

1998 ◽  
Vol 72 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Jiří Frýda ◽  
Robert B. Blodgett
Keyword(s):  
New Species ◽  
Lower Devonian ◽  
New Genus ◽  
New Genus And Species ◽  
Early Devonian ◽  
West Central ◽  
The Family ◽  
First Time ◽  
Stratigraphic Range

Two new cirroidean gastropod genera, Alaskiella (family Porcelliidae) and Alaskacirrus (family Cirridae), from the Emsian (late Early Devonian) of west-central Alaska (Medfra B-4 quadrangle) are described. The shell of Alaskiella medfraensis new genus and species exhibits inclined heterostrophic coiling. This shell character is known among other members of the subclass Archaeogastropoda, but is recorded for the first time within members of the superfamily Cirroidea. Inclined heterostrophic coiling of the shell was probably developed independently in several different groups of the subclass Archaeogastropoda. The new genus Alaskacirrus, represented by Alaskacirrus bandeli new species, is the oldest and only known Paleozoic member of the family Cirridae. This suggests that the family Cirridae was separated from the family Porcelliidae since at least Early Devonian time and that it most probably developed from the subfamily Agnesiinae of the family Porcelliidae. Thus, the stratigraphic range of the family Cirridae is at least from Lower Devonian to Cretaceous, an interval of about 350 million years.

Emsian (Late Early Devonian) sponges from west-central and south-central Alaska

2009 ◽  
Vol 83 (2) ◽  
pp. 293-298
Author(s):  
J. Keith Rigby ◽  
Robert B. Blodgett ◽  
Nicolle K. Anderson
Keyword(s):  
Early Devonian ◽  
Type Section ◽  
South Central ◽  
West Central ◽  
Associated Species

Relatively common specimens of the hypercalcified agelasiid sponge Hormospongia labyrinthica Rigby and Blodgett, 1983 and specimens of associated species of Hormospongia have been previously reported from Emsian and Eifelian stratigraphic units at several localities in south-central and southeastern Alaska (Rigby and Blodgett, 1983). Those sponges were first described from the type section of the Eifelian Cheeneetnuk Limestone in the McGrath A-5 quadrangle. Since then several additional specimens of Hormospongia labyrinthica have also been collected from a new locality in the Talkeetna C-6 quadrangle in south-central Alaska (Figs. 1, 2.1), and are documented here.

Trend of Extreme Precipitations Indices in West-central Côte d’Ivoire: Case of the Lobo Watershed

2020 ◽  
Vol 5 (10) ◽  
pp. 1281-1287
Author(s):  
F. B. Allechy ◽  
M. Youan Ta ◽  
V. H. N’Guessan Bi ◽  
F. A. Yapi ◽  
A. B. Koné ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Crop Yields ◽  
Extreme Rainfall ◽  
Cote D’Ivoire ◽  
West Central ◽  
Côte D'ivoire ◽  
Northern Half ◽  
Agricultural Potential ◽  
Annual Total

The Lobo watershed located in the west-central part of Côte d'Ivoire is an area with high agricultural potential, influenced by climate variations and changes that reduce crop yields. The objective of this study is to analyse trends in ETCCDI extreme rainfall indices from rainfall data from 1984 to 2013 using ClimPACT2 software. This study shows that the trend of the indices: number of consecutive wet days (CWD), number of rainy days (R1mm) and the cumulative annual total rainfall (PRCPTOT) is decreasing. On the other hand, the number of consecutive dry days (CDD) is on the rise. In general, the whole basin has experienced a decrease in rainfall as well as wet sequences and an increase in dry sequences. These different trends observed in this study are more pronounced in the northern half of the watershed.

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