| Main Ref. | Poutiers, J.M., 1998 |
| Appearance refers to |
| specialized organs | |
| different appearance | |
| different colors | |
| remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Diagnosis | Shell equivalve, thick and inflated, very inequilateral, posteriorly expanded. Shape somewhat irregular, elongate rectangular in outline, with strongly protruding umbones anteriorly and a broad rounded keel from umbones to posteroventral margin. Posterior margin obliquely truncate, ventral margin slightly sinuous with a well-developed byssal gape. Cardinal area wide and riblets crossed by irregular growth marks, and a few larger radial ribs on posterodorsal slope. Periostracum coarsely pilose, mainly persisting towards shell margins. Hinge straight very long and narrow. Internal margins smooth. Colour: Outside of shell often encrusted with marine growths; posterior half dark brown, anterior half creamy white with zebra-like brown stripes. Inner side more or less strongly tinged with dark brown. |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin |
| Attributes |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes |
| spines | |
| soft-rays | |
| Pelvics | Attributes |
| Position | |
| spines | |
| soft-rays |