Phylogenetic inference was conducted on the multiple sequence alignment of full-length NS1 and VP1/2 sequences of the partetraviruses. The phylogenetic trees ( Fig. 1 and 2) showed a common topology, and placed the presently identified viruses in the same clade as known partetraviruses. Bovine partetraviruses HK4 and HK5 formed a cluster with known bovine partetraviruses, although the genetic distance between HK5 and the other bovine partetraviruses suggested that it should be considered as a different genotype of bovine partetravirus. The 4 identical strains of ovine parvovirus are clearly shown to be distinct from the other known partetraviruses, and are most closely related to bovine partetraviruses. Based on these results, we recognize these ovine parvoviruses as a new member of the partetraviruses and propose to describe them as ovine partetraviruses. The phylogeny is consistent with the hypothesis of virus-host co-evolution, as the sheep and cattle are both ruminants and are evolutionarily closer to each other than to the other hosts like pigs, chimpanzee and humans.