The greater Basque Country comprises the Autonomous Communities of the Basque Country and Navarre in Spain and the Northern Basque Country in France. The Prehistory of the region begins with the arrival of the first hominin settlers during the Paleolithic and lasts until the conquest and colonisation of Hispania by the Romans after the Second Punic War, who introduced comprehensive administration, writing and regular recordings. Basque people are the only Western Europeans that speak a non-Indo-European language - Euskera - without having any known contemporary European ethnic or linguistic relatives. A 2015 DNA study supports the idea that the Basques descend from Neolithic farmers who mixed with local hunters and were subsequently isolated for millennia. Lower and Middle Paleolithic The earliest Homo erectus migration events into Western Europe and the Basque Country had very little impact on history, culture and settlement forms. Notable is nonetheless the Atapuerca Mountains complex in northern Spain, that was inhabited in sizable communities by Homo antecessor (or Homo erectus antecessor), Homo heidelbergensis and Neanderthals for many generations. The first substantial settler groups have arrived during the Riss-Würm interglacial period, between 150,000 and 75,000 BP, who left traces of Acheulean culture and technology. These groups usually settled in the riverine lowlands, near the rivers Ebro and Adour in the regions of Araba, Navarre, Labourd and Lower Navarre. Homo neanderthalensis Mousterian culture is introduced during the Middle Paleolithic. Neanderthals left a rather rich and long cultural sequence in northern Spain, who in the Basque Country populated the high coastal lands of Biscay and Gipuzkoa. Neanderthal remains have also been found in the Lezetxiki and Axlor caves. Upper Paleolithic Homo sapiens first arrived on the Iberian peninsula during the Upper Paleolithic period that starts the process of replacement of Mousterian industries by the Aurignacian culture. A number of researchers suggest that the Ebro river functioned for extended periods of time as a major biological/cultural frontier that separated the anatomically modern humans in the Franco-Cantabrian region to the north from the rest of the Iberian peninsula which is occupied by Neandertals for several thousand years longer. As modern humans settled in the northern territories from around 40,000 years BCE, earliest evidence from the south dates to between 34,000 and 32,000 years BCE. The term Vasco-Cantabrian is now often used for the coastal area of the modern Basque Country and neighbouring Cantabria. Châtelperronian culture Whether Homo sapiens or Neanderthal are