Georg Mayer, Paul M. Whitington, Paul Sunnucks, Hans-Joachim Pflüger (2010): A revision of brain composition in Onychophora (velvet worms) suggests that the tritocerebrum evolved in arthropods. BMC Evolutionary Biology 10: 255. http://www.biomedcentral.com/1471-2148/10/255
Georg Mayer (2006): Structure and development of onychophoran eyes: What is the ancestral visual organ in arthropods? Arthropod Structure & Development Volume 35, Issue 4: 231–245. doi:10.1016/j.asd.2006.06.003
Jennifer K. Grenier, Theodore L. Garber, Robert Warren, Paul M. Whitington, Sean Carroll (1997): Evolution of the entire arthropod Hox gene set predated the origin and radiation of the onychophoran/arthropod clade. Current Biology 7: 547–553. doi:10.1016/S0960-9822(06)00253-3
Janssen, R., Eriksson, B. J., Budd, G. E., Akam, M., Prpic, N.-M. (2010): Gene expression patterns in an onychophoran reveal that regionalization predates limb segmentation in panarthropods. Evolution & Development 12: 363–372. doi:10.1111/j.1525-142X.2010.00423.x
Lars Podsiadlowski, Anke Braband, Georg Mayer(2008): The complete mitochondrial genome of the Onychophoran Epiperipatus biolleyi reveals a unique transfer RNA set and provides further support for the Ecdysozoa hypothesis. Molecular Biology and Evolution 25 (1): 42-51. doi:10.1093/molbev/msm223
