Moroccan cave fossils yield a missing link in human origins

The new finding has a potential to revise theories on early human evolution

- FRANZ LIDZ

RESEARCHERS ON WEDNESDAY announced that fossils discovered in a Moroccan quarry are about 773,000 years old, filling a critical gap in the understanding how of human beings came to be. The find has the potential to revise theories on early human evolution.

The bones of hominins, primates leading up through the human lineage that branched off from chimpanzees and walked upright, are described in a study published in the journal Nature. The fossils come from Grotte a Hominidés, a cave site in Casablanca that may have been a den of prehistoric carnivores.

The site offers a window into a prehistoric coastal ecosystem, where the Atlantic meets a varied terrain of sand dunes, karsts and marine terraces. The region once was a vibrant habitat of wetlands and swamps that supported abundant wildlife, with panthers prowling the savannas and hippos, crocodiles, hyenas and jackals all sharing the muddy shores and surrounding areas.

The assemblage of hominin remains featured in the study includes a nearly complete adult jawbone, half an adult jawbone, the jawbone of a child, several vertebrae and isolated teeth. These remains are distinct from the fossils of the nearby Jebel Irhoud site, which at 300,000 years of age are currently the oldest known evidence of our species, Homo sapiens. These rare, precisely dated bones are significant because they come from a period in the African fossil record from 600,000 to one million years ago from which similar specimens are yet to be found. This time frame is crucial, as it is when the African lineage leading to Homo sapiens is thought to have diverged from Eurasian hominins that produced Neanderthals and Denisovans.