The subfamily is defined on the basis of phylogenetic relationships of complete large (L) protein amino acid sequences (Rima et al., 2018).
Genus demarcation criteria
See discussion under family description.
Members of all species of the subfamily Avulavirinae have hemagglutinin and neuraminidase activities. They share greater sequence relatedness within the genus than with members of other genera. A major feature that distinguishes avulaviruses and rubulaviruses from the other subfamilies is that the exact copy of the P/V mRNA encodes a phosphoprotein (P) and the edited form encodes a Zn2+-binding cysteine-rich protein (V). However, there are some exceptions indicated in the data bank entries. The avulaviruses have the canonical 6 gene order 3′-N-P/V-M-F-RBP-L-5′ of the family. The intergenic sequences are of variable length. All members lack a non-structural protein (C) ORF. The avulavirus P protein is substantially smaller than that of the respiroviruses or morbilliviruses.