Jebel Irhoud or Adrar n Ighoud (; , Moroccan Arabic: ), is an archaeological site located just north of the locality known as Tlet Ighoud, approximately south-east of the city of Safi in Morocco. It is noted for the hominin fossils that have been found there since the discovery of the site in 1960. Originally thought to be Neanderthals, the specimens have since been assigned to Homo sapiens and, as reported in 2017, have been dated to roughly 300,000 years ago ( for the Irhoud 3 mandible, based on other fossils and the flint artefacts found nearby).
Site
The site is the remnant of a solutional cave filled with of deposits from the Pleistocene era, located on the eastern side of a karstic outcrop of limestone at an elevation of . It was discovered in 1961 when the area was being mined for the mineral baryte. A miner discovered a skull in the wall of the cave, extracted it, and gave it to an engineer, who kept it as a souvenir for a time. Eventually, it was handed over to the University of Rabat, which organized a joint French-Moroccan expedition to the site that was headed by anthropologist Émile Ennouchi.
Ennouchi's team identified the remains of approximately 30 species of mammals, some of which are associated with the Middle Pleistocene, but the stratigraphic provenance is unknown. Another excavation was carried out by Jacques Tixier and Roger de Bayle des Hermens in 1967 and 1969, during which 22 layers were identified in the cave. The lower 13 layers were found to contain signs of human habitation including a tool industry classified as Levallois Mousterian.
Human remains
The site is particularly noted for the hominin fossils found there. Ennouchi discovered a skull that he termed Irhoud 1. It is now on display in the Rabat Archaeological Museum. He discovered part of another skull, designated Irhoud 2, the following year and subsequently uncovered the lower mandible of a child, designated Irhoud 3. Tixier's excavation found 1,267 recorded objects including skulls, a humerus designated Irhoud 4, and a hip bone recorded as Irhoud 5.
Further excavations were carried out by American researchers during the 1990s as well as by a team led by Jean-Jacques Hublin from 2004. Animal remains found at the site have enabled the ancient ecology of the area to be reconstructed. It was quite different to the present and probably represented a dry, open, and perhaps, steppe-like environment roamed by equids, bovids, gazelles, rhinoceros, and various predators.
Dating
Initially, the finds were interpreted as Neanderthal, as the stone tools found with them were believed to be associated exclusively with Neanderthals. They also had archaic phenotypical features believed to be representative of the Neanderthals, rather than Homo sapiens. They were thought to be approximately 40,000 years old, but this was thrown into doubt by faunal evidence suggesting a Middle Pleistocene date, approximately 160,000 years ago. Because of that, the fossils were reappraised as representing an archaic form of Homo sapiens or perhaps a population of Homo sapiens that had interbred with Neanderthals. This was consistent with the concept that the then-oldest-known remains of a Homo sapiens, dated to approximately 195,000 years ago and found in Omo Kibish, Ethiopia, indicated an eastern African origin for humans at approximately 200,000 years ago. The Ethiopian Omo remains were more recently dated to about 233,000 years old.
However, dating carried out by the Max Planck Institute for Evolutionary Anthropology in Leipzig revealed that the Jebel Irhoud site was far older than first thought. Fresh excavations carried out in 2004 by the Hublin team revealed more than 20 new bones from the remains of at least five people, and a number of stone tools. The finds included part of a skull, a jawbone, teeth, and limb bones that had come from three adults, a juvenile, and a child aged about seven-and-a-half years old. The facial bones resembled those of humans today, but had much larger lower jaws and more elongated posterior braincases. They have similar features to the Florisbad Skull dating to 260,000 years ago found at the other end of the continent, in Florisbad, South Africa, which now has been attributed to Homo sapiens on the basis of the Jebel Irhoud finds.