Thyasira Leach in Lamarck, 1818

Type species. Tellina flexuosa Montagu, 1803

Diagnosis. Small to medium sized thyasirids with a well defined posterior area with a sulcus and a well defined sub-marginal sulcus with an auricle. Sculpture of commarginal growth lines and weak ridges. Hinge lacking teeth, ligament in a resilifer set in the auricle. Gills of two demibranchs, fleshy, Type 3L of Oliver (2014).