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 |
| Protostomia incertae sedis | |
| class | Hyolitha Marek, 1963 † |
| Hyolitha incertae sedis | |
| genus | Haplophrentis Babcock & Robison, 1988 † |
| species | Haplophrentis carinatus (Matthew, 1899) † |