The analysis of morphological variation   in this group is complicated due to low character variation and nondiscrete   differentiation. We hence conducted comprehensive DNA sequencing across the   geographic range of Rivacindela to   provide the scaffold for assigning species membership. We find that the   various existing procedures for DNA-based species delimitation identify   biologically meaningful groups. The new likelihood method for analyzing   branching rate produced results closely similar to those obtained with   character-based methods but does not require prior assumption of population   boundaries and can provide a statistical measure of confidence to the   assessment of species limits.

由于性状变异小，分化不明显，这一群体的形态变异分析比较复杂。因此，我们在Rivacidela属分布的地理范围内进行了全面的DNA测序，以提供评估其物种成员的框架。我们发现，现有的各种基于DNA的物种界定程序确定了具有生物学意义的类群。分析分枝率的新似然方法产生的结果与基于特征的方法得到的结果非常相似，但不需要预先假设种群边界，并且可以为物种界限的评估提供一个统计的置信度度量。