Independent lineages from five zoogeographic realms: the mitochondrial genome of Ornithodoros (Pavlovskyella) gurneyi Warburton, 1926 (Acari: Argasidae) confirms paraphyly of the subgenus Pavlovskyella Pospelova-Shtrom, 1950

Abstract

Mitochondrial (mt) genomes have played a major role in elucidating evolutionary relationships in ticks (Ixodida), especially in soft ticks (Argasidae). Mitochondrial genomes have been sequenced for representatives of most of the genera and other major lineages. This includes members of the Afrotropical, Nearctic, Neotropical and Palearctic Pavlovskyella Pospelova-Shtrom, 1950, which is a subgenus of Ornithodoros Koch, 1844. These continent-associated lineages do not form a monophyletic group: rather, the subgenus Pavlovskyella is paraphyletic. The only zoogeographic region for which mt genomes are not available is the Australasian region. Here we report the first mt genome of an Australasian Pavlovskyella: Ornithodoros (Pavlovskyella) gurneyi Warburton, 1926, the kangaroo soft tick. [The companion paper to the present work, Barker et al. (2025), presents the mt genome, 18S and 28S rRNA of the only other known Australasian Pavlovskyella, McMillans Australian tree-hollow argasid, Ornithodoros (Pavlovskyella) macmillani Hoogstraal & Kohls, 1966.] Our phylogenetic trees reveal that the two Australasian Pavlovskyella have their own clade (i.e. are sister-taxa) which does not have a sister-group relationship with species of Pavlovskyella from any of the four other zoogeographic regions. We propose that the Pavlovskyella from the Afrotropical, Australasian, Nearctic, Neotropical and Palearctic zoogeographic regions have independent evolutionary histories and thus are best considered different genera. Molecular dating leads us to propose that continental drift may have caused the evolution of five different lineages of Pavlovskyella, each in a different zoogeographic region of the world.

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