Maximum likelihood tree for the M segment with 1,000 bootstrap pseudoreplications. New sequences from the present study are in bold. The state and date of collection are listed for each sequence. All clades with bootstrap support > 50% are indicated with a dot and the % of bootstrap support. The SN-Type clades 1 and 2 proposed by Rowe et al. (1995) are indicated with grey circles as is clade 3 in which all but one of the sequences in the present study arose.