Phylogenetic analysis of Phalangida (Arachnida, Opiliones) using two nuclear protein-encoding genes supports monophyly of Palpatores

Recent phylogenetic studies of Opiliones have shown that Cyphophthalmi and Phalangida (= Palpatores + Laniatores) are sister groups, but higher relati onships within Phalangida remain controversial. Current debate focuses on w hether Palpatores (= Caddoidea + Phalangioidea + Ischyropsalidoidea + Trogu loidea) is monophyletic or paraphyletic, with Ischyropsalidoidea + Troguloi dea (= Dyspnoi) being more closely related to Laniatores. The latter hypoth esis was favored in recent combined studies of ribosomal DNA and morphology . Here higher relationships within Phalangida are examined using two nuclea r protein-encoding genes, elongation factor-1 alpha (EF-1 alpha) and RNA po lymerase II (Pol II), from 27 opilion species representing seven superfamil ies. Cyphophthalmi was used as the outgroup. Nucleotide and inferred amino acid sequences were analyzed using maximum-parsimony and maximum-likelihood methods. All analyses recovered Palpatores as the monophyletic sister grou p to Laniatores with moderate to strong empirical support. Most palpatorean superfamilies were also recovered, but relationships among them were ambig uous or weakly supported. A monophyletic Palpatores was also obtained when EF-1 alpha and Pol II sequences were analyzed together with 18S and 28S rDN A sequences.