Phylum: Haptophyta (Haptophytes)
The taxonomy presented here follows AlgaeBase as at early August 2026. Doubtless many new species await discovery and formal description, and this may necessitate the erection of novel higher taxonomic ranks.
Subphylum: Haptophytina
Class: Coccolithophyceae
Order: Coccolithales
Family: Coccolithaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Tergestiella adriatica Kamptner (1940) | - | northern Adriatic Sea & Japan | Rediscovered | Access |
Families: Calcidiscaceae, Calyptrosphaeraceae, Hymenomonadaceae, Noelaerhabdaceae, Watznaueriaceae
—No subordinate taxa
Orders: Ceratolithales, Coccolithales, Isochrysidales, Phaeocystales, Prymnesiales, Syracosphaerales, Zygodiscales
—No subordinate taxa
Classes: Haptophyta classis incertae sedis, Pavlovophyceae, Rappephyceae
—No subordinate taxa
Subphylum: Centroheliozoa
Class: Centrohelea
—No subordinate taxa
Statistics
| Conservation status | Number of taxa (in percentage) |
| Extinct | 0 |
| Missing | 0 |
| Extinct in the Wild | 0 |
| Possibly Extinct in the Wild | 0 |
| Globally Rediscovered | 1 (100%) |
| Rediscovered in the Wild | 0 |
| Reintroduced | 0 |
| Uncertain status | 0 |
| Hypothetical | 0 |
| Total | 1 (100%) |
| Erroneously listed | 0 |
| Invalid | 0 |
| Grand total | 1 (100%) |