Jebel Irhoud Moroccan Arabic: It is noted for the hominin fossils that have been found there since the site's discovery in Originally thought to be Neanderthalsthe specimens have since been assigned to Homo sapiens and have been dated atyears old.
Ennouchi's team identified the remains of around 30 species of mammals, some of which are associated with the Middle Pleistocenebut the stratigraphic provenance is unknown. Another excavation was carried out by Earliest dating of homo sapiens fossils Tixier and Roger de Bayle des Hermens in and in which "Earliest dating of homo sapiens fossils" layers were identified in the cave.
The lower 13 layers were found to contain signs of human habitation including an industry classified as Levallois Mousterian. The site is particularly noted for the hominin fossils found there.
Ennouchi discovered a skull which he termed Irhoud 1 and 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, 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 in the s and by a team led by Jean-Jacques Hublin from It was quite different to the present and probably represented a dry, open and perhaps steppe -like environment roamed by equidsbovidsgazellesrhinoceros and various predators.
The finds were initially interpreted as Neanderthalas the stone tools found with them were believed to be associated exclusively with Neanderthals. They were thought to be around 40, years old, but this was thrown into doubt by faunal evidence suggesting a Middle Pleistocene date, aroundyears ago.
The fossils were reappraised as representing an archaic form of Homo sapiens or perhaps a population of Homo sapiens that had interbred with Neanderthals. 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. The finds included part of a skull, a jawbone, teeth and limb bones which had come from three adults, a juvenile, and a child aged about seven and a half years old.
They have similar features to the Florisbad Skull dating toyears ago found at the other end of the continent, in FlorisbadSouth Africa, which has been attributed to Homo sapiens on the basis of the Jebel Irhoud finds.
The tools were found alongside gazelle bones and lumps of charcoal, indicating the presence of fire and probably of cooking in the cave. The gazelle bones showed characteristic signs of butchery and cooking, such as cut marks, notches consistent with marrow extraction, and charring.
This enabled the researchers to use thermoluminescence dating to ascertain when the burning had happened, and by proxy the age of the fossil bones, which were found in the same deposit layer. The burnt tools were dated to aroundyears ago, indicating that the fossils are of about the same age. This "Earliest dating of homo sapiens fossils" was confirmed by recalculating the age of the Irhoud 3 mandible, which produced an age range compatible with that of the tools at roughlytoyears old.
If they hold up, these dates would make the remains by far the earliest known examples of Homo sapiens. This suggests that, rather than arising in East Africa aroundyears ago, modern humans may already have been present across the length of Africayears earlier. According to study author Jean-Jacques Hublin, "The idea is that early Homo sapiens dispersed around the continent and elements of human modernity appeared in different places, and so different parts of Africa contributed to the emergence of what we call modern humans today.
The rise of modern humans Earliest dating of homo sapiens fossils thus have taken place on a continental scale rather than being confined to a particular corner of Africa. Hublin and his team also attempted to obtain Earliest dating of homo sapiens fossils DNA sample from these fossils, but these attempts were unsuccessful. Genomic analysis would have provided necessary evidence supporting the conclusion that these fossils are representative of the main lineage leading up to modern humanity, and that Homo sapiens had dispersed and developed all across Africa.
Because of the unclear boundaries between different species of the Homo genus, and the lack of genomic evidence from these fossils, some doubt the classification of these fossils as Homo sapiens.
Questions remain over the classification of these fossils. When comparing the fossils with those of modern humans, the main difference is the elongated shape of the fossil braincase.
According to the researchers, this indicates that brain shape, and possibly brain functions, evolved within the Homo sapiens lineage and relatively recently. Teeth crowns took a longer time to form than in modern humans.
Overall, Jebel Irhoud specimens were similar to later Aterian and Iberomaurusian specimens.