A new syringophilid mite species, Stibarokris nielseni sp. nov., from Manx Shearwater Puffinus puffinus is described. This finding is the third record of quill mite species for Iceland and the first one outside Galliformes. The new species differs from all other species of this genus in the following characters: tarsal claws of legs III and IV are distinctly more massive and strongly curved in comparison to claws of legs I and II (vs. tarsal claws are similar in shape and size in other Stibarokris species); the hysteronotal teeth are replaced ventrally (vs. situated laterally). The distribution of the quill mites of the genus Stibarokris on birds strongly corresponds to avian lineages grouped in the recently established clade Feraequornithes comprising the orders Pelecaniformes, Suliformes, Ciconiiformes, and Procelariiformes. Of these orders, quill mites were not confirmed only on representatives of Sphenisciformes. Probable explanation could be their highly specialized way of life and/or insufficient sampling efforts. Additionally, considering the recent reconstructions of avian phylogeny, the presence of Stibarokris on flamingos (Phoenicopteriformes), which are distant from Feraequornithes, is most likely the result of successful host switching.