Brain and eyes of Kerygmachela reveal protocerebral ancestry of the panarthropod head

Park, Tae-Yoon S.; Kihm, Ji-Hoon; Woo, Jusun; Park, Changkun; Lee, Won Young; Smith, M. Paul; Harper, David A.T.; Young, Fletcher; Nielsen, Arne T.; Vinther, Jakob

Abstract

Recent discoveries of fossil nervous tissue in Cambrian fossils have allowed researchers to trace the origin and evolution of the complex arthropod head and brain based on stem groups close to the origin of the clade, rather than on extant, highly derived members. Here we show that Kerygmachela from Sirius Passet, North Greenland, a primitive stem-group euarthropod, exhibits a diminutive (protocerebral) brain that innervates both the eyes and frontal appendages. It has been surmised, based on developmental evidence, that the ancestor of vertebrates and arthropods had a tripartite brain, which is refuted by the fossil evidence presented here. Furthermore, based on the discovery of eyes in Kerygmachela, we suggest that the complex compound eyes in arthropods evolved from simple ocelli, present in onychophorans and tardigrades, rather than through the incorporation of a set of modified limbs.

Citation

Park, T. S., Kihm, J., Woo, J., Park, C., Lee, W. Y., Smith, M. P., …Vinther, J. (2018). Brain and eyes of Kerygmachela reveal protocerebral ancestry of the panarthropod head. Nature Communications, 9(1), Article 1019. https://doi.org/10.1038/s41467-018-03464-w

• Journal Article Type: Article
• Acceptance Date: Feb 15, 2018
• Online Publication Date: Mar 9, 2018
• Publication Date: Mar 9, 2018
• Deposit Date: Mar 9, 2018
• Publicly Available Date: Mar 9, 2018
• Journal: Nature Communications
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: 1019
• DOI: https://doi.org/10.1038/s41467-018-03464-w
• Public URL: https://durham-repository.worktribe.com/output/1338107