To use any of these data, please cite:Cofran, Z., Boone, M., and Petticord, M. 2021. Virtually estimated endocranial volumes of the Krapina Neandertals. American Journal of Physical Anthropology 174:117–128. https://doi.org/10.1002/ajpa.24165 S2. Endocranial volumes of Middle Pleistocene hominins from this and other studies A comma separated values (.csv) format file containing 10 ECVs for each of the Krapina hominins as determined by warping human reference endocasts, and single ECV estimates for the Sima de los Huesos hominins, pre-Würm Neandertals, and Würm Neandertals. The Sima de los Huesos data are from Poza-Rey and colleagues (2018). Würm and pre-Würm Neandertal values come mainly from DeSilva (2018), but in some cases more recent and/or virtually-estimated values were used instead (i.e., Braüer et al., 2020; Bruner & Manzi, 2008; Neubauer et al., 2018; Rougier, 2003). References Braüer, G., Pitsios, T., Säring, D., von Harling, M., Jessen, F., Kroll, A., & Groden, C. (2020). Virtual reconstruction and comparative analyses of the Middle Pleistocene Apidima 2 cranium (Greece). Anatomical Record 303: 1374–1392. doi: 10.1002/ar.24225 Bruner, E., & Manzi, G. Paleoneurology of an “Early” Neandertal: Endocranial size, shape, and features of Saccopastore 1. Journal of Human Evolution 54: 729–742. Neubauer, S., Hublin, J.-J., & Gunz, P. (2018). The evolution of modern human brain shape. Science Advances, 4: eaao5961. doi: 10.1126/sciadv.aao5961 Poza-Rey, E. M., Gómez-Robles, A., & Arsuaga, J. L. (2019). Brain size and organization in the Middle Pleistocene hominins from Sima de los Huesos. Inferences from endocranial variation. Journal of Human Evolution, 129: 67–90. doi:10.1016/j.jhevol.2019.01.006. Rougier, H. (2003). Étude descriptive et comparative de Biache-Saint-Vaast 1 (Biache-Saint-Vaast, Pas-de-Calais, France) (doctoral dissertation). Sciences de l’Homme et Société. Université de Bordeaux, Bordeaux. S3. Terry Collection endocast landmark data A comma separated values (.csv) format file containing all 441 landmarks for all 40 adult human endocasts from the Terry Collection (Copes, 2012), used in this study. Note that the original CT scan data can be downloaded from Dr. Lynn Copes’ website (http://www.lynncopes.com/human-ct-scans.html). The .csv file contains a column for individual ID, landmark name, and the x-, y-, and z-coordinates of the landmark. The ten individuals used as references to reconstruct the fossil endocasts are identified as TC 712, TC 942, TC 956, TC 1015, TC 1155, TC 1233R, TC 1293, TC 1306, TC 1323, and TC 1356. Reference Copes, L. E. (2012). Comparative and Experimental Investigations of Cranial Robusticity in Mid-Pleistocene Hominins (doctoral dissertation). Arizona State University, Tempe. S4. Fossil endocast landmark data A comma separated values (.csv) format file containing all 441 landmarks for Spy II and each of the five Krapina hominins. For each fossil, the dataset contains only the landmarks located on preserved endocranial surface, as originally digitized in Viewbox4 (dHAL Software) prior to missing data estimation as described in the Methods section of the manuscript. .csv file contains a column for individual ID, landmark name, and the x-, y-, and z-coordinates of the landmark.