| A (2 species) | 
| Adelogyrinus - Unavailable | 
| Adelospondylus - Carboniferous | 
| B (0 species) | 
| C (0 species) | 
| D (0 species) | 
| E (0 species) | 
| F (0 species) | 
| G (0 species) | 
| H (0 species) | 
| I (0 species) | 
| J (0 species) | 
| K (0 species) | 
| L (0 species) | 
| M (0 species) | 
| N (0 species) | 
| O (0 species) | 
| P (1 species) | 
| Palaeomolgophis - Early Carboniferous, 345.3-326.4 Ma | 
| Q (0 species) | 
| R (0 species) | 
| S (0 species) | 
| T (0 species) | 
| U (0 species) | 
| V (0 species) | 
| W (0 species) | 
| X (0 species) | 
| Y (0 species) | 
| Z (0 species) |