Species Account

Thracia convexa (W Wood, 1815)

Thracioidea : Thraciidae

Tebble name: Thracia convexa (W Wood)
Smith & Heppell name: Thracia convexa (W Wood, 1815)

To size: To 70mm. Shell Structure: Thin, brittle. Equivalve: Almost equivalve, right valve slightly larger than left. Equilateral: Inequilateral, beaks posteriorly orthogyrate. Beak of LV sits in hole in RV. Outline: Subtrigonal, posterior dorsal margin convex to a narrowly rounded posterior margin. Ventral margin almost straight, leading to a narrowly rounded anterior margin. Anterior dorsal margin is convex but rises higher than posterior. umbonal region very tumid. Contour: Ridge runs from dorsal to ventral margin posteriorly.

Sculpture: Concentric lines very close together on most of the shell but are fewer on posterior region. Margin: Smooth. Ligament: External and internal; external short dark brown arch behind beaks, internal on a short resilifer. Hinge: Lithodesma short, thin and often lost. Pallial Musculature: Pallial sinus shallow, around a third the length of shell. Not confluent. Periostracum: Pale brown/beige. Colour: White.

Distribution & Ecology

In mud and sand offshore. Found all around the UK except E coast Scotland and from Norwegian Sea to the Mediterranean.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species


Listed are literature citing Thracia convexa (W Wood, 1815). Reference containing the species Type Description is highlighted.

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.
Wood W 1815. General conchology or a description of shells, arranged according to the Linnean system, London p. 92, pl 18 Fig 1.


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Record last modified: 22/03/2016