Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD-2300 specimen

[EN] The chapter of the dissertation: Paleoneurología comparada de los linajes Neandertal y Sapiens. Nuevos evidencias aportadas por los fósiles de El Sidrón (Asturias), reproduces entirely the manuscript of: Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD-2300 specimen.Journal of Anatomy 233: 33-45 (2018). [ES] El capítulo de la tesis doctoral: Paleoneurología comparada de los linajes Neandertal y Sapiens. Nuevos evidencias aportadas por los fósiles de El Sidrón (Asturias), reproduce íntegramente la información del artículo: Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD-2300 specimen.Journal of Anatomy 233: 33-45 (2018).The comparative analysis of the endocranial surface of the El Sidrón new occipital fragment SD-2300 shows meaningful differences in the configuration of the occipital pole region between neandertals and anatomically modern humans (AMH). The particular asymmetries found in neandertals in the venous sinus drainage and the petalial patterns are recognizable in this new specimen as well. In addition, the supra- and infracalcarine fossae of the occipital pole region appear to deviate obliquely from the mid-line when compared with sapiens. Due to the excellent preservation conditions of SD-2300, the main sulci and gyri of the occipital pole area have been identified, this degree of detail being uncommon in a fossil specimen; in general, the gyrification pattern is similar to AMH, but with some notable differences. Particularly interesting is the description of the lunate and the calcarine sulci. The lunate sulcus is located close to the occipital pole, in a similar posterior position to in other Homo species. Regarding the calcarine sulcus, there are significant differences in the primary visual cortex, with the V1 area, or Brodmann area 17, being larger in Homo neanderthalensis than in Homo sapiens. This may lead to greater visual acuity in neandertals than in sapiens.This work was supported by the MINECO projects CGL2012-36682 and CGL2016-75109-P and by the Convenio CSIC-Principado de Asturias 201130E019Peer reviewe