Meganodontia Bouchet and Cosel, 2004

Amano, Kazutaka, Little, Crispin T. S. & Campbell, Kathleen A., 2018, Lucinid bivalves from Miocene hydrocarbon seep sites of eastern North Island, New Zealand, with comments on Miocene New Zealand seep faunas, Acta Palaeontologica Polonica 63 (2), pp. 371-382 : 373

Genus Meganodontia Bouchet and Cosel, 2004

Type species: Meganodontia acetabulum Bouchet and Cosel, 2004 ; Recent , Tashi fishing ground, off Tashi, NE coast of Taiwan .

Remarks.— Meganodontia acetabulum Bouchet and Cosel, 2004 has a very large shell (up to 150 mm in length). Bouchet and Cosel (2004) listed the generic characters: edentulous hinge, thick-shelled, large anterior adductor muscle scar broadening ventrally, less prominent umbo and maximum height located behind the umbo. However, based on our observations of published photographs of the Italian fossil species Meganodontia hoernea ( Des Moulins, 1868) , this latter character seems to be absent, so it may be a species rather than generic-level character.

Within the subfamily Pegophyseminae , Pegophysema Stewart, 1930 differs from Meganodontia by having a smaller and thinner anterior adductor muscle scar, a more swollen umbo, a straighter hinge and some secondary pallial attachment scars ( Bouchet and Cosel 2004; Taylor and Glover 2005). In addition, most Recent species of Pegophysema come from very shallow water sites, whereas fossil and Recent Meganodontia species come from deep-sea vent and seep sites ( Bouchet and Cosel 2004; Taylor and Glover 2005, 2016; Kiel and Hansen 2015; Kiel and Taviani 2017).