Glycymeris (Axinola) septentrionalis (Middendorf, 1849)

western bittersweet

Description: Shell shape is oval to triangular, with a slightly longer anterior end and rounded posterior end. Sculpture comprises faint radial striae (lines), although is often eroded. Hinge plate arched with two series of teeth.

Size: 40-50 mm.

Ecology: Semi-infaunal on coarse-sediment from the intertidal to bathyal (0-400 m).

Geological range: Reported from as early as the Early Miocene, but widespread from the Late Miocene-Recent (12-0 million years ago). Geologically early records require validation.

Geographic distribution: Alaska (60°N) to Baja California (25°N), México and northwestern Pacific (Kamchatka). Reported from the Tachilni Formation (Miocene, Alaska), Jewett Sand Formation (Miocene, California), Santa Margarita Formation (Miocene, California), Ermanovskaya Suite (Miocene, Kamchatka), Towsley Formation (Pliocene, California), Empire Formation (Pliocene, Oregon), Lomita Marl (Pleistocene, California), and Quaternary terrace deposits of California and Baja California.

Click on thumbnails for larger view

• 
• 
•