Position in a system
| system | Vitae - living organisms |
| domain | Eukaryota Whittaker & Margulis, 1978 - lifeforms with nucletic cells |
| superregnum | Unikonta |
| system | Opisthokonta Cavalier-Smith, 1987 |
| kingdom | Animalia Linnaeus, 1758 - animals |
| subregnum | Eumetazoa Butschli, 1910 |
| divisio | Bilateria Hatschek, 1888 - bilaterians |
| subdivisio | Protostomia Grobben, 1908 - protostomes |
| phylum | Bryozoa Ehrenberg, 1831 |
| class | Gymnolaemata Allman, 1856 |
| order | Cheilostomata |
| suborder | Flustrina d'Orbigny, 1852 |
| superfamily | Microporoidea |
| family | Calescharidae Cook & Bock, 2001 |
| genus | Tretosina Canu & Bassler, 1927 † |