Correction to: Cambrian origin of the arachnid brain (Current Biology, (2025), 35, 15, (3777-3785.e2), (S096098222500822X), 10.1016/j.cub.2025.06.063)

(Current Biology 35, 3777–3785.e1–e2; August 4, 2025) In the version of this article initially published, the described position of Mollisonia symmetrica was as sister to Xiphosura and Pycnogonida, and Fuxianhuia protensa was described as a stem—instead of crown—mandibulate. Based on the presented phylogenetic trees, the respective sentences have been corrected online: M. symmetrica is now described as resolved at the base of Arachnida in all phylogenetic analyses, and F. protensa is described as a crown mandibulate with close affinities to Myriapoda.