Stockwell , S. A. 1990. University Microfilms International, Ann Arbor, Michigan. The pages are printed front and back and the color photos are not included. Overall, I was not happy with the way it turned out. Click on the dissertation's title above for further information.
Emphasis is on the relationships among Recent genera, but major fossil groups are considered.
The position of the Scorpionida among the major chelicerates is also analyzed. All currently recognized non-buthid genera are incorporated into the analysis with some genera being further divided into subgenera or species groups. The Buthidae are treated only at the family level. Seven fossil groups at various taxonomic levels are also included. The Arachnida, Eurypterida, and Xiphosura are utilized as outgroups.