| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Acanthocephala | 0 | 0 | 14 |
| Acarina | 0 | 0 | 10 |
| Lissamphibia (amphibians) | 0 | 0 | 10 |
| Acoela (acoel flatworms) | 0 | 0 | 6 |
| Actinopterygii (ray-finned fishes) | 0 | 0 | 16 |
| Amoebozoa (amoeboid protists) | 0 | 0 | 4 |
| Amphionidacea | 0 | 0 | 2 |
| Amphipoda Latreille 1816 (amphipods) | 0 | 0 | 6 |
| Metazoa (Animal) | 131 | 0 | 0 |
| Annelida (segmented worms) | 0 | 0 | 7 |
| Anthozoa Ehrenberg 1834 (anemones and corals) | 0 | 0 | 6 |
| Antipatharia (black corals) | 0 | 0 | 10 |
| Apusozoa | 0 | 0 | 4 |
| Ascidiacea Blainville 1824 (Ascidian) | 0 | 0 | 15 |
| Asteroidea de Blainville 1830 (sea stars) | 0 | 0 | 12 |
