These files contain tomographic data, segmentation masks (both contained in .mcs file), and surface meshes (in .ply format) for the Carboniferous fish fossil NMMNH P-80347 type 5 palaeonisciform/“elonichthyid” indeterminate 1. The .mcs file can only be opened in the proprietary software Materialise Mimics; meshes can be opened in several programs (e.g., MeshLab; https://www.meshlab.net/).