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 | Brachiopoda Duméril, 1806 - lamp shells |
| subphylum | Rhynchonelliformea |
| class | Rhynchonellata |
| order | Athyridida Boucot, Johnson & Staton, 1964 † |
| suborder | Dayiidina Johnson, 1974 † |
| superfamily | Dayioidea Waagen, 1883 † |
| family | Dayiidae Waagen, 1883 † |
| genus | Dayia Davidson, 1881 † |
| species | Dayia barrandei (Schuchert & Cooper, 1930) † |