Phylogeny of quill mites of the family Syringophilidae (Acari: Prostigmata) based on their external morphology

External morphological characters were used to reconstruct a phylogeny of the mite family Syringophilidae (Acariformes: Cheyletoidea), which are permanent parasites inhabiting the quills of bird feathers. A total of 53 syringophilid genera and 79 characters were included in the data matrix; maximum parsimony (MP) and Bayesian analyses (BA) were performed to determine their phylogenetic relationships. The consensus of unweighted MP trees was weakly resolved. Only four generic groups were recognized: Aulonastus + Krantziaulonastus (i) and (Creagonycha + Kethleyana) + (Megasyringophilus + Selenonycha) (ii) - both with low Bremer support (BS 1); the subfamily Picobiinae - Picobia, Calamincola, Columbiphilus (Neopicobia + Rafapicobia) (BS 12) (iii) and Psittaciphilus generic group - (Meitingsunes + Psittaciphilus) (Peristerophila + (Neoperisterophila + (Castosyringophilus + Terratosyringophilus))) (BS 2) (iv). BA revealed a consensus tree with a topology similar to MP. The two main groups recognized by MP, the subfamily Picobiinae and Psittaciphilus, both received the highest support of 1; while two other groups recognized by MP - Aulonastus + Krantziaulonastus and (Creagonycha + Kethleyana) + (Megasyringophilus + Selenonycha) received relatively low support of 0.73-74 and 0.76-77, respectively. The consensus of re-weighted MP trees was almost fully resolved but, the majority of the generic groups, excluding the Picobiinae and Psittaciphilus were supported by just a few non-unique synapomorphies with a high probability of homoplastic origin. The most intriguing result is the paraphyly of the Syringophilinae in respect to picobiines. The pattern of the re-weighted tree demonstrates only patches of parallel evolution at the level of syringophilid genera and bird orders. Perhaps horizontal shifts on phylogenetically distant hosts and colonization of quill (calamus) types other than primaries and secondaries were also important in the evolution of the syringophilids.