A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska

Abstract

Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds.

Three new deep-sea species of Thyasiridae (Mollusca: Bivalvia) from the abyssal plain of the northwestern Pacific Ocean and hadal depths of the Kuril-Kamchatka Trench

“…According to shell proportions and hinge structure, this species, in actuality, more conforms to the genus Mendicula ( Payne & Allen, 1991 ; Kamenev & Nadtochy, 2000 ; Oliver & Killeen, 2002 ; Zelaya, 2010 ). However, unlike Mendicula , it has a distinct, long and deep escutcheon ( Valentich-Scott et al, 2014 ). Examination of the anatomy of A. careyi is needed for a more reliable generic assignment.…”

“…However, after studying the type of Maorithyas , Maorithyas marama Fleming, 1950, Oliver with coauthors ( Oliver & Sellanes, 2005 ; Oliver, 2014 ; Åström, Oliver & Carrolla, 2017 ) came to the conclusion that allocation of this species to Maorithyas is incorrect as both shell and anatomy are not in agreement. Valentich-Scott et al (2014) also examined the shell morphology of holotypes of M. marama and M. hadalis and came to the conclusion that M. hadalis does not correspond to Maorithyas and perhaps belongs to a new genus of the Thyasiridae. Despite that its anatomy was not investigated, it was reported that the digestive system of A. hadalis is greatly reduced and the large and thick ctenidium harbors intracellular symbiotic bacteria ( Fujikura et al, 1999 ; Okutani, Fujikura & Kojima, 1999 ; Fujiwara et al, 2001 ).…”

ZooKeys 500: traditions and innovations hand-in-hand servicing our taxonomic community

“…Quite a number of interesting zoological discoveries were announced in the journal and attracted large audiences and considerable media interest (see also Tables 2 and 3 ). Among those, worth mentioning: a new procyonid mammal, the Olinguito, from the Andes ( Helgen et al 2013 ); a new genus of monk seals from the Caribbean Sea ( Scheel et al 2014 ); a new genus and several new species of bats from Africa and the Neotropics ( Reeder et al 2013 ; Velazco and Patterson 2014 ); a new subgenus and four new species of electric fishes from the Amazon and Congo river basins ( Sullivan et al 2013 ; Lavoué and Sullivan 2014 ); a new genus and species of rove beetles collected by Charles Darwin 180 years ago and published on his birthday ( Chatzimanolis 2014 ); a new genus and species of ancient clams found in the depths of the Arctic Ocean ( Valentich-Scott et al 2014 ) and many others.…”

Paleogene marine bivalves of the deep-water Keasey Formation in Oregon, Part III: The heteroconchs

“…Discoveries of new and unusual deep-water thyasirids suggest previously unrecognized evolutionary radiations. They include new genera from the west coast of North America (Coan and Valentich-Scott 2012), the west coast of Africa (Oliver 2014), and the Arctic Ocean (Valentich-Scott et al 2014). A review of Magellanic and Antarctic thyasirids (Zelaya 2009) includes one new species and new generic assignments for four other species .…”

“…Two new taxa have been described from >7,000 m in the Japan Trench (Okutani et al 1999). The environmental setting for Arctic Ocean species is notably similar to that of the Keasey thyasirids: shells were recovered from a sediment core with authigenic carbonates and methane hydrates (Valentich-Scott et al 2014). The active Cascadia Margin also contains sites of unusual of crustal fluid discharge that are neither cold seeps nor hydrothermal vents.…”