Get ready to rewrite the fossil record one more time. Researchers have unveiled a 12 million year old hominid fossil from Spain, with startlingly modern facial features, and it may indicate our evolutionary origins are more complicated than is commonly accepted.
The team responsible for studying the specimen is led by Salvador Moyà-Solà, director of the Institut Català de Paleontologia (ICP) at the Universitat Autònoma de Barcelona. He and his colleagues have spent five years examining the fossilized cranium since its discovery in 2004. The fragile remains, which preserve most of the face and mandible, were found in the Abocador de Can Mata area in L'Anoia, Barcelona, a locale known for its fossil-rich terrain.
The specimen has been classified Anoiapithecus brevirostris. The Anoiapithecus genus refers to its L'Anoia origins, while brevirostris is in reference to its unusually modern features. The fossil has been nicknamed "Lluc", probably in homage to the most famous hominid specimen, the Australopithecus afarensis skeleton known as Lucy.
It's the specimen's facial morphology that has really attracted interest. While most of the primates in the Hominidae family are prognathic, or marked by a protruding jaw, Anoiapithecus brevirostris has a remarkably flat face. Its facial features are comparable only to the Homo genus, of which we're the only living representative and which didn't even exist for nearly ten million years after Anoiapithecus brevirostris.
That's not to say Lluc is some sort of time-displaced missing link between modern humans and ancient apes. Instead, the researchers speculate this may be an example of evolutionary convergence, where similar environmental conditions produce similar adaptations. If nothing else, this discovery may help researchers better understand the occurrence of reduced prognathism in certain strands of the Hominidae family.
Anoiapithecus brevirostris may also help illuminate where hominids originated. Some paleontologists have pointed to the kenyapithecines as the most primitive hominoids, suggesting they are the ancestors of all other hominids. These primates, which have been found in Africa and Eurasia, date back to the Middle Miocene era, roughly the same time period as Anoiapithecus brevirostris. However, Lluc's features are a peculiar mix of those resembling modern hominids, Eurasian kenyapithecines, and afropithecids, another group of primitive hominoids found in Africa.
In trying to make sense of this muddled evolutionary genealogy, Moyà-Solà and his team have turned to the controversial "into Africa" theory. This essentially holds that kenyapithecines initially left Africa for Eurasia around 15 million years ago, at which time a number of hominid species radiated out into several regions. Anoiapithecus brevirostris, which settled in Spain, would have been one of this initial wave of hominids. Later, the ancestors of humans, gorillas, and chimpanzees returned to Africa. It's also possible the ancestors of the great apes and humans never left Africa, but the forebears of the pongines, which includes modern orangutans, did leave for Eurasia.
As always, there's only so much one can conclude from a single cranium, no matter how extraordinary it might be. Anoiapithecus brevistros complicates an evolutionary picture that was already plenty muddled, but one can only hope the continued accumulation of data will someday make the millions of years of our evolutionary history a bit clearer.