[viruses]
   Realm Riboviria
     Order Nidovirales
       Suborder Cornidovirineae [monotypic]
         Family Coronaviridae
           Subfamily Orthocoronavirinae
             1 Genus Alphacoronavirus
             2 Genus Betacoronavirus
             3 Genus Deltacoronavirus
             4 Genus Gammacoronavirus