|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Bivalvia - Pectinida - Anomiidae
It was assigned to Plicatulidae by Marwick (1953); to Placunidae by Ronchetti (1970); to Terquemiidae by Vokes (1980); to Pterioida by Sepkoski (2002); and to Anomiidae by Todd and Palmer (2002) and Lazo and Damborenea (2011).
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|J. A. Todd and T. J. Palmer 2002||Medium-sized (< 60mm high), subcircular, thin-shelled and compressed anomiid. RV extremely thin, closely adpressed to substratum, with byssal notch (open foramen) surrounding an uncalcifed byssal plug;
medium sized adductor scar adjacent to postero-ventral margin of foramen. LV exterior with very fine to moderately strong radiating riblets. Interior with shallowly arched crus with adjoining buttress extending posteroventrally for length of foramen. Two prominent muscle scars present; a moderate-sized posterior pedal (byssal) retractor scar at 25±50 per cent height; touching at its posteroventral edge a smaller adductor scar. Also present is a minute anterior pedal retractor scar. Shell structure: RV, outer shell layer
extremely thin, prismatic; inner shell layer of cross lamellar aragonite: LV, outer shell layer of foliated calcite; extensive cross lamellar aragonite inner shell layer, extending 80±90 per cent of distance to ventral margin.