Hominin fossils from Morocco may be close ancestors of modern humans
The jawbones and vertebrae of a hominin that lived 773,000 years ago have been found in North Africa and could represent a common ancestor of Homo sapiens, Neanderthals and Denisovans
The jawbone of an ancient hominin found at Grotte à Hominidés in Morocco
Hamza Mehimdate, Programme Préhistoire de Casablanca
Fossils nearly three-quarters of a million years old, discovered in North Africa, may belong to a common ancestor of Neanderthals, Denisovans and modern humans that lived shortly before the three hominin lineages split.
It is thought that the last common ancestor of modern humans, Neanderthals and Denisovans lived sometime between 765,000 and 550,000 years ago. But exactly when and where it lived remain two of the great questions of human evolution.
The new fossils may not be the last common ancestor of the three human species, says Jean-Jacques Hublin at the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, but they are certainly close to the point at which ancient human lineages diverged.
Hublin and his colleagues analysed several fossils found in a cave called Grotte à Hominidés on the outskirts of Casablanca, Morocco, including two adult jawbones, a child’s jawbone and several vertebrae. One of the adult jawbones was reported in a previous study in 1969, but the rest have been described for the first time.
The fossilised molars are similar to those of early Homo sapiens and Neanderthals, but the jaw shape resembles older African humans, like Homo erectus.
Fortuitously for the scientists, the Moroccan hominins lived at around the same time as a shift in the Earth’s magnetic field, which is recorded in the geological layer in which the fossils were found, allowing them to be dated to around 773,000 years ago.
Hublin says the discoveries fill a “major gap” in the African hominin record between 1 million and 600,000 years ago. Paleogenetic studies indicate that this is when the ancestors of Neandertals and Denisovans branched off the lineage that led to H. sapiens. Neanderthals went on to dominate Europe for hundreds of thousands of years. Denisovans travelled as far as East Asia, and H. sapiens are thought to have continued to evolve in Africa.
The newly described fossils were near contemporaries of a Spanish population of hominins called Homo antecessor, which has previously been considered as a possible common ancestor between and Neanderthals.
