Species Account

Thracia distorta (Montagu, 1803)

Thracioidea : Thraciidae

Tebble name: Thracia distorta (Montagu)
Smith & Heppell name: Thracia distorta (Montagu, 1803)

To size: To 27mm. Shell Structure: Brittle. Equivalve: Inequivalve, RV more convex than LV. Equilateral: Inequilateral, beaks anteriorly. Outline: Oval to elongate oval. Anterior slopes steeply (oval) or curves broadly (elongate oval) to a straight ventral margin. Posterior margin either broadly rounded (oval) or curves less broadly than anterior.

Sculpture: Irregular concentric lines and coarse granulated surface. Margin: Smooth, often broken. Ligament: External and internal; external short behind beaks, internal on a short semi-circular resilifer. Hinge: Small lithodesma, often lost. Pallial Musculature: Shallow, broad pallial sinus. Periostracum: Reddish/yellowish brown. Colour: White.

Distribution & Ecology

In rock crevices low in the intertidal zone at intermittent locations around the UK in low numbers. Distributed from Norway to Morocco and into the Mediterranean.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species


Listed are literature citing Thracia distorta (Montagu, 1803). Reference containing the species Type Description is highlighted.

Montagu G 1803. Testacea Britannica, or natural history of British shells, marine, land and the fresh-water, including the most minute: systematically arranged and embellished with figures Romsey, London. 606pp, 16pls.
Soot-Ryen T 1941. Northern Pelecypods in the collection of Tromsø Museum I Order Anomalodesmacea Families Pholoadomyidae. Thraciidae and Periplomatidae. Tromsø Museums Arshefter Naturhistorisk Avd. Nr. 17. 61: 1-41, 10 pls.


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Record last modified: 22/03/2016