Tetraclita squamosa collected from Hin Ngam beach, Nakhon Si Thammarat (BUU16.TC.TS01). A. Dorsal and ventral view of external shell, B. External (left panel) and internal (right panel) view of tergum (upper panel) and scutum (lower panel), C. External (upper panel) and internal (lower panel) view of shell plates, D. Close up on external surface of shell, E–H. Light microscopy on mouthparts, E. Labrum, E. Close up on the teeth of the labrum, G. Mandible, G. Close up on the pectinated lower margin of mandible. E–H. Scale bars in µm. Abbreviations: c, carina; l, latus; r, rostrum.