Molecules reject an opheliid affinity for Travisia (Annelida).

The phylogenetic position of the polychaete genus Travisia within Annelida is a matter of ongoing debate. Travisia is usually placed within Opheliidae, but morphological similarities with Scalibregmatidae, such as a rugose epidermis, are obvious. To further examine placement of this enigmatic group, we examined 28 annelid species from a range of families, but with special emphasis on Scalibregmatidae and Opheliidae. Our data set consisted of four genes: 16S rDNA, 18S rDNA, 28S rDNA and Histone 3. By combining genes and conducting Maximum Likelihood, Maximum Parsimony and Bayesian analysis, our results strongly support a sister-group relationship of Travisia and Scalibregmatidae. None of the phylogenetic analyses clustered Travisia with or within Opheliidae and such placements are also significantly rejected by hypothesis testing. Moreover, we obtained new insights on relationships within Opheliidae and Scalibregmatidae. Within Opheliidae, the traditional classification into Opheliinae and Ophelininae received strong support. [ABSTRACT FROM AUTHOR]