fossiles
| Nom | Type | Notoriété | Popularité |
|---|---|---|---|
| Obruchevichthys | Taxon | 6 | 0.0 |
| Octacnemidae | Taxon | 11 | 0.2 |
| Odonterpeton | Taxon | 6 | 0.2 |
| Odontogriphus | Taxon | 10 | 0.7 |
| Oesia | Taxon | 4 | 0.0 |
| Oikopleuridae | Taxon | 10 | 0.2 |
| Oistodella | Taxon | 1 | 0.0 |
| Oistodontidae | Taxon | 1 | 0.0 |
| Oistodus | Taxon | 1 | 0.0 |
| Olfactores | Taxon | 23 | 5.6 |
| Olivierosuchus | Taxon | 4 | 0.0 |
| Omomyidae | Taxon | 19 | 1.1 |
| Onchopristis | Taxon | 18 | 2.8 |
| Onega Stepanovi | Taxon | 7 | 0.0 |
| Onychodontiformes | Taxon | 13 | 0.9 |
| Onychodus | Taxon | 10 | 0.6 |
| Ophiacodon | Taxon | 23 | 2.1 |
| Ophiacodontidae | Taxon | 20 | 0.6 |
| Ophiderpeton | Taxon | 15 | 0.1 |
| Oromycter Dolesorum | Taxon | 9 | 0.0 |
| Osteichthyes | Taxon | 90 | 52.9 |
| Osteolepiformes | Taxon | 15 | 2.5 |
| Osteostraci | Taxon | 24 | 1.3 |
| Ostracodermi | Taxon | 36 | 3.6 |
| Otsheria | Taxon | 8 | 0.0 |
| Otsheriidae | Taxon | 2 | 0.0 |
| Ozarkodina | Taxon | 5 | 0.0 |
| Ozarkodinida | Taxon | 3 | 0.0 |
| Ozarkodinina | Taxon | 1 | 0.0 |
| Palaeohatteria | Taxon | 7 | 0.3 |
| Palaeohatteriidae | Taxon | 4 | 0.1 |
| Palaeomeryx | Taxon | 4 | 0.3 |
| Palaeospondylus | Taxon | 10 | 0.1 |
| Paleodictyon | Taxon | 7 | 0.0 |
| Palmatolepidae | Taxon | 2 | 0.1 |
| Palmatolepis | Taxon | 2 | 0.2 |
| Paltodus | Taxon | 1 | 0.0 |
| Pampaphoneus | Taxon | 8 | 0.4 |
| Panderichthyidae | Taxon | 5 | 0.0 |
| Panderichthys | Taxon | 21 | 2.5 |
| Panderichthys | Taxon | 5 | 0.5 |
| Panderodontida | Taxon | 2 | 0.0 |
| Panderodontidae | Taxon | 2 | 0.0 |
| Panderodus | Taxon | 4 | 0.1 |
| Pantelosaurus | Taxon | 12 | 0.4 |
| Pantylus | Taxon | 9 | 0.2 |
| Parabrontopodus | Taxon | 3 | 0.0 |
| Paraconodontida | Taxon | 3 | 0.0 |
| Paracordylodontidae | Taxon | 2 | 0.0 |
| Paracordylodus | Taxon | 2 | 0.0 |