| Main Ref. | Carvalho-Filho, A., S. Santos and I. Sampaio, 2010 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | fusiform / normal |
| Cross section | compressed |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | |
| Diagnosis |
Macrodon atricauda differs from M. ancylodon by the following characteristics: pored lateral line scales 49-63 (vs. 66-78); anal fin soft rays 9-10, rarely 8 (vs. usually 8, occasionally 9); dorsal fin soft rays 27-28, rarely 29 (vs. 28-29, rarely 27); pectoral fin rays 16-17 (vs. 15-16); largest front canines 2.5 to 3.2 in eye length, proportionally smaller and thinner when compared to M. ancylodon (Ref. 88197). |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | 49 - 63 |
| 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 | 7 - 9 |
| on upper limb | 2 - 3 |
| total | 9 - 12 |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | 2 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 11 - 11 |
| Soft-rays total | 27 - 29 |
| Adipose fin |
| Attributes |
| Fins number | 1 |
| Spines total | 2 - 2 |
| Soft-rays total | 8 - 10 |
| Pectoral | Attributes |
| Spines | |
| Soft-rays 16 - 17 | |
| Pelvics | Attributes |
| Position | |
| Spines 1 | |
| Soft-rays 5 - 5 |