Obelisk (biology)

An obelisk is a "viroid-like element" of a type first described in a January 2024 preprint, whose authors say that "Obelisks form their own distinct phylogenetic group", as their RNA sequences, discovered by computer-aided metatranscriptomics, are not homologous with the genetic code of any other life form.

With their relationship to other organisms being unknown, they are an example of the incertae sedis.