Positive strand RNA virus, virions are enveloped, spherical, and 45–60 nm in diameter.
Family: Arteriviridae; subfamilies:
Prior to 2016, Arterivirus was the sole genus. The genus was dissolved in 2016, and the family was reorganized to have five genera: Dipartevirus, Equartevirus, Nesartevirus, Porartevirus, and Simartevirus. The family was reorganized again in 2018, establishing the current subfamilies and lower taxa.