The Phylogeny of the order Pseudoscorpiones

Abstract

Pseudoscorpiones is an order of arachnids, members of which are commonly known as book scorpions or false scorpions. Since they first appeared in the Middle Devonian period, they have acted as important predators in microhabitats. The order’s placement within Arachnida and its internal evolutionary relationships remains contentious. Furthermore, the fossil record of Pseudoscorpiones contains several extinct families as well as extinct genera within extant families, with a total of 49 fossil species across the Phanerozoic. The last morphological pseudoscorpion phylogeny was published by Harvey (1992), but this lacked the fossil record. I analysed the matrix with a different software and a range of extinct species. In this thesis, the literature review compares the foundations of Harvey (1992) alongside to more recent analyses of Psuedoscorpiones phylogeny to reflect upon the strengths, limitations, results, and the discussed hypotheses. I then update Harvey (1992) with the addition of fossils to the matrix. The addition of fossils does not significantly alter the relationships between extant families. There is evidence to both support the original placement of species (i.e. Pseudocheirium insulae etc.) and to contradict it (i.e. Geogarypus gorskii etc.). I also support hypotheses of Harvey (1992) (e.g. Dracochelidae is found within Chthonioidea, Epiocheirata and Iocheirata.) The addition of fossil taxa to a morphological analysis of Pseudoscorpiones is novel. This matrix provides an opportunity for newly discovered species (extant or fossil) to be placed within a cladistics framework. Future studies should focus on including more details to profiles of genera to reduce unknown or incorrect past interpretations, and thus to progress to a more reliable phylogenetic analysis.

Date of Award	31 Dec 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	David Legg (Supervisor) & Russell Garwood (Supervisor)