ID Keys
*Images in development

Hiatelloidea & Basterotiidae

Beaks close to the midline
Go to #2
Beaks towards the anterior
Go to #3
Outline elongate oval, hinge teeth rudimentary, periostracum persistent dark brown to black [Arctic]
Cyrtodaria kurriana
Outline subquadrate with a median sulcus, gaping widely, single cardinal in LV
Panomya norvegica
Shell initially biangulate posteriorly with 2 radial ridges but becoming eroded, LV with 2 small cardinal teeth
Go to #4
Shell not biangulate, hinge with a single cardinal peg or lacking teeth
Go to #5
Boring into calcareous rocks, posterior radial angles lacking spines
Hiatella rugosa
Nestling in crevices, posterior radial angles persistent often bearing short hollow spines
Hiatella arctica
RV with a single flange-like cardinal, posterior angle rounded
Saxicavella jeffreysi
Hinge lacking teeth, posterior angle subacute
Atopomya dolobrata