Complex sentence: The sister species to "A. macrodactylum", "A. laterale", is distributed in eastern North America, but the species phylogeny for Ambystomatidae is tentative and in need of further testing.
Split into simpler sentences: The sister species to "A. macrodactylum" is "A. laterale", which is distributed in eastern North America. However, the species level phylogeny for Ambystomatidae is tentative and in need of further testing.