| Main Ref. | Whitehead, P.J.P., 1985 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | males alike females |
| Different colors | males alike females |
| Remarks |
| Striking features | striking shape of body |
| Body shape lateral | elongated |
| Cross section | compressed |
| Dorsal head profile | clearly concave |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | terminal |
| Type of scales | |
| Diagnosis |
Belly with an uninterrupted keel of about 29 or 30 scutes, the outer edges of the scutes distinctly serrated. Upper jaw broad at midpoint, tapering posteriorly, the tip reaching or surpassing the gill opening; no hypo-maxilla. Pectoral fins large; dorsal fin rather small, set far back on body; anal fin long. |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | 0 - 0 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | 0 - 0 |
| Scale rows below lateral line | 0 - 0 |
| Scales around caudal peduncle | |
| Barbels | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | 18 - 26 |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | greatly reduced or absent |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 61 - 68 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays | |
| Pelvics | Attributes suppressed/absent |
| Position absent | |
| Spines 0 | |
| Soft-rays 0 - 0 |