ML trees were derived using a general time-reversible model employing estimates of the proportion of invariable sites and the Gamma distribution. Significant bootstrap support (> 50%) from 1,000 replicates of the ML and the maximum parsimony (MP) method are shown above each node in the order ML/MP. Support for a node of less than 50% is indicated by an asterisk. Underlined samples are those sequenced in this study. The scale bar represents the distance in substitutions per nucleotide. GenBank accession numbers are shown in parentheses.