Molecular phylogeny supports S-chaetae as a key character better than jumping organs and body scales in classification of Entomobryoidea (Collembola)

• DOI: 10.1038/srep12471
• Publication Date: 2015-07-27T09:52:33Z
• Authors: Feng Zhang; Dan-Dan Sun; Dao-Yuan Yu; Bei-Xin Wang
• Keywords: Chaeta; Polyphyly; Convergent evolution; Morphology; Parallel evolution; Molecular Phylogenetics

The jumping organ (furcula) is the most characteristic structure among collembolans, and it of great taxonomical values at higher levels. largest superfamily Entomobryoidea traditionally classified into four families only by morphology furcula. Actually, many taxa these are strikingly similar in without considering phylogeny was reconstructed here based on mitochondrial ribosomal fragments. This indicated that both Paronellidae Cyphoderidae were ingroups within Entomobryidae with former polyphyletic. Topology tests, which used likelihood Bayesian approaches, also rejected traditional hypotheses relying furcula morphology. Further ancestral state reconstructions have revealed characters, i.e., body scales, had multiple independent origins whereas tergal specialized chaetae (S-chaetae) exhibited strong phylogenetic signals. By integrating molecular morphological evidence, results this study drastically undermine present classification Entomobryoidea. Tergal S-chaetotaxic pattern combination other characters more reasonable taxonomy suprageneric levels than convergent provides new insights organ, could be adaptively modified during evolution Collembola.