ID Keys


Sculpture of acentric grooves decreasing in spacing towards the margins
Digitaria digitaria
Sculpture smooth or commarginal lines or ridges
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Rounded triangular, commonly taller than long
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Subtrigonal or subovate to slightly triangular
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Very fine commarginal lines and irregular growth stops, found to 200m
Goodallia triangularis
Broad commarginal ridges, found intertidal and to 200m
Astarte montagui
Subovate, thick, dark periostracum covering commarginal lines and irregularly spaced low ridges, Arctic/subarctic
Astarte borealis
Rounded subtrigonal/triangular, regular spaced commarginal ridges
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Subtrigonal, dense commarginal, narrow ridges that are acute on the posterior area, bathyal
Astarte acuticostata
Oval to subtrigonal, commarginal ridges rounded
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Broadly rounded oval outline, raised commarginal ridges, magnified periostracum a mesh of microscopic elliptical-oval pits
Astarte elliptica
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Ridges smooth, widely spaced, magnified periostracum fine wavy linear pattern, widely distributed throughout study area
Astarte sulcata
Ridges closely spaced with secondary commarginal lines especially over the posterior area, magnified periostracum lacking wavy linear pattern, boreal arctic species
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Magnified periostracum commarginally wrinkled but not punctate, lustrous
Astarte crenata
Magnified periostracum commarginally wrinkled and micro-punctate
Astarte crebricostata