Preliminary Study on Phylogenetic Relationships of Cypridocopina(Ostracoda:Podocopida)Based on 18S rDNA Sequences

Nucleotide sequences for the 18S rDNA(1720 bp)of 11 ostracoda species,representing 3 su- perfamilies and 5 families,were analyzed based on maximum parsimony(MP)and neighbor joining(NJ). The topologies of phylogenetic relationships gained by two analytic methods are similar.The results shown: 1)Cypridocopina forms a monophyletic group,2)Close rationship between Pontocypridoidea and Macrocyp- ridoidea can be postulated;3)Cypridoidea is considered as a monophyletic group,but the rationships among cypridoidean families could not be resolved from 18S rDNA.