Fig. 1 Virtual cranial endocast of Chilecebus based on high-resolution CT scanning images. Virtual cranial endocast of Chilecebus based on high-resolution CT scanning images. Gray shadows indicate reconstructed portions. (A) Dorsal. (B) Ventral. (C) Left lateral. (D) Right lateral. (E) Anterior. (F) Posterior. as, arcuate sulcus; cg, cavernous groove; cs, central sulcus; fos, fronto-orbital sulcus; fr, foramen rotundum; hf, hypoglossal foramen; iam, internal acoustic meatus; icc, internal carotid canal; ips, inferior petrosal sinus; jf, jugular foramen; ob, olfactory bulb; of, optic foramen; pf, paraflocculus; pgf, postglenoid foramen; pss, petrosquamous sinus; rs, rhinal sulcus; sf, sagittal fissure; sof, superior orbital fissure; Ss, Sylvian sulcus; ss, sigmoid sinus; st, sella turcica; sts, superior temporal sulcus; ts, transverse sulcus; v, vermis. Xijun Ni et al. Sci Adv 2019;5:eaav7913 Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).