[viruses]
   Realm Riboviria
     Order Nidovirales
       1 Suborder Abnidovirineae [monotypic]
       2 Suborder Arnidovirineae [monotypic]
       3 Suborder Cornidovirineae [monotypic]
       4 Suborder Mesnidovirineae
       5 Suborder Monidovirineae [monotypic]
       6 Suborder Ronidovirineae
       7 Suborder Tornidovirineae [monotypic]