The tree was generated from a Cobalt (NCBI) multiple fusion protein sequence alignment, by the fast minimum evolution method, and visualized using the Fig Tree program. Representative members of each genus of the Paramyxovirinae and Pneumovirinae subfamilies are shown. APIV1, avian parainfluenza virus 1; CDV, canine distemper virus; HeV, Hendra virus; HMPV, human metapneumovirus; HPIV3, human parainfluenza virus 3; HRSV, human respiratory syncytial virus; MeV, measles virus; NDV, Newcastle disease virus; NiV, Nipah virus; PIV-5, parainfluenza virus 5.