Non-Traditional Characters in the Assessment of Caecilian Phylogenetic Relationships

Phylogenetic relationships among caecilians and of caecilians to other amphibians are not well understood. A generally accepted hypothesis of relationships exists for families of caecilians, but relationships among genera and among species remain unresolved for the most part. Current hypotheses of relationships are based largely on morphological characters, primarily external features and some osteology; molecular data are accruing. However, I contend that morphology has not been explored adequately in the search for characters of systematic utility. I present a summary of work in progress on the examination of aspects of the neuroanatomy and reproductive morphology of caecilians and a discussion of the possible contribution of such characters to phylogenetic analysis. I conclude that morphologists should, whenever possible, both place their work in a phylogenetic context, and use their data to contribute to phylogenetic hypotheses.