| Main Ref. | Springer, S. and G.H. Burgess, 1985 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | elongated |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | placoid scales |
| Diagnosis |
A very small, black shark with a short and bluntly rounded snout (its length 5.7-7.5% TL in adults); head and body nearly cylindrical anteriorly, tapering unevenly to a slender caudal peduncle; moderately large eyes; dermal denticles, very small needle-like to spine-like, covering whole body except narrowly along lips, gill slit margins, around cloacal opening, and dorsal surface of claspers. Pectoral fins lobate; small pelvic fins. |
| 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 | 2 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin |
| Attributes | more or less truncate; confluent |
| Fins number | 1 |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes other (see diagnosis) |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes more or less normal |
| Position abdominal behind origin of D1 | |
| Spines | |
| Soft-rays |