Postnatal endocranial volume (ECV) growth in Neanderthals, rAMHS, and chimpanzees. (A) Growth as a percentage of neonate taxon-specific mean ECV values (Neanderthals: 400 ccm, rAMHS: 400 ccm, chimpanzees: 155 ccm). (B) Growth as a percentage of adult taxon-specific mean ECV values (1,500 ccm, 1,350 ccm, 386 ccm). Solid lines: rAMHS mean ± SD; dashed lines: chimpanzee mean ± SD (data from refs. , , and ). Circles: Neanderthal individuals (from left to right and bottom to top: Mezmaiskaya, Dederiyeh 1 and 2, Pech de l'Azé, Subalyuk 2, Roc de Marsal, Gibraltar 2, Engis 2, La Quina 18, Teshik Tash, Le Moustier 1, Tabun 1, Gibraltar 1, La Ferrassie 1, Amud 1); horizontal bars: estimated range of individual age. In A, note that Neanderthals are at the upper range of the rAMHS distribution. In B, note complete overlap between Neanderthal and rAMHS trajectories, and overlap between chimpanzee and hominin trajectories after an age of 2 years.