Ovaliviridae
Ovaliviridae is a family of viruses of archaea that is not assigned to any higher taxonomic ranks. The family contains a single genus, Alphaovalivirus, which contains a single species, Sulfolobus ellipsoid virus 1. The linear genome of dsDNA is 23,219 bp with 172 bp inverted terminal repeats. "Sulfolobus ellipsoid virus 1" was isolated from an acidic hot spring (86−106oC, pH 2.2−2.5) in Laguna Fumarólica, Costa Rica; the only known host is "Sulfolobus" sp. A20.