Homo Antecessor

Homo antecessor is the designation given a fossil hominid from the Lower Pleistocene of Atapuerca, Spain, defined in 1997 by Bermúdez de Castro, Arsuaga, Carbonell, Rosas,Martínez, and Mosquera, in Sciencemagazine. The name antecessor is the Latin word meaning “explorer,” “pioneer,” or “early settler.” Assigning this name, they emphasized that these hominids belong to the first population as yet known in the European continent. The fully modern mid-facial morphology of the fossils antedates other evidence of this feature by about 650,000 years. The midfacial and subnasal morphology of modern humans may be a retention of a juvenile pattern that was not yet present in Homo ergaster. Consequently, Homo antecessor may represent the last common ancestor for Neandertals and modern humans.

From 1994 to 1996, nearly 80 human fossil remains were recovered from level six (Aurora stratum) of the Pleistocene cave site of Gran Dolina (TD), Sierra de Atapuerca, Burgos, Spain. These remains were found in sediments located about 1 m below the Matuyama-Brunhes boundary. In 1997, Bermúdez de Castro and his colleagues described the TD6 fossils and defined a new species, which exhibits a unique combination of cranial, mandibular, and dental traits. Midfacial topography shows a modern pattern and infraorbital surface with true canine fossa. The supraorbital torus is double-arched. The superior border of the temporal squama is convex, and there is the presence of a styloid process. The mylohyoid groove extends anteriorly nearly horizontal and courses into the mandibular body, the thickness of which is clearly less than that of H. ergasterand Homo habilis s.s. There is an absence of alveolar prominence at the M1 level. The extramolar sulcus is narrow. The lateral prominentia is smooth and restricted to the level of M2. The design of the inner aspect of the corpus is similar to that of European Middle Pleistocene fossils. Mandibular incisors are buccolingually expanded with respect to H. habilis s.s., but postcanine teeth are smaller and within the range of H. ergaster, Homo erectus, and Homo heidelbergensis. The maxillary incisors are shovel-shaped. The mandibular canine is mesiodistally short.

Source: Photo by Eustoquio Molina.

The holotype is a fragment of right mandibular body with M1, M2, and M3 (ATD6–5) and an associated set of teeth from the same individual. Holotype and paratypes are provisionally housed in the Museo Nacional de Ciencias Naturales, Madrid, Spain. The final repository of the fossils is the Museo de Burgos, Spain.