Ancient Face Fragment Rewrites Early Human History in Europe

A groundbreaking discovery in northern Spain has unearthed a partial human face belonging to a primitive archaic human, pushing back the timeline of known hominin presence in Western Europe by hundreds of thousands of years. This facial fragment, estimated to be between 1.1 million and 1.4 million years old, predates previously discovered remains of Homo antecessor at the same site and suggests a more complex picture of early human occupation in the region. The finding, published in the journal Nature, introduces Homo affinis erectus as a significant player in the story of human evolution in Europe.

The fossil, nicknamed "Pink" by the research team, was recovered in 2022 from the Sima del Elefante site. Its significance lies in its age, making it the oldest human fossil ever found in Western Europe. This discovery challenges the long-held belief that Homo antecessor, whose remains were dated around 900,000 years ago, was the first hominin species to inhabit this part of the continent.

"This paper introduces a new actor in the story of human evolution in Europe, Homo affinis erectus," stated Rosa Huguet, a paleoanthropologist at the Institut Català de Paleoecologia Humana i Evolució Social and co-author of the study, during a press briefing. "This finding allows us to accept that during the early Pleistocene, more than one early human species lived in Europe, and that the first hominid to inhabit western Europe was not Homo antecessor, as we previously believed.”

The designation "Homo aff. erectus" is crucial. The "aff." stands for affinis, a Latin term meaning "related to." In taxonomic usage, it indicates that the discovered species shares similarities with another known species – in this case, Homo erectus – but may not be definitively classified as the same. Homo erectus was a widespread and long-lived human species, existing from approximately 2 million to 100,000 years ago and considered a direct ancestor of modern humans. The discovered fossil exhibits enough similarities to Homo erectus to warrant the "affinis" designation, implying a close relationship but leaving open the possibility that it represents a distinct, previously unknown species.

The team’s decision to nickname the fossil "Pink" carries a delightful double meaning. Beyond the obvious reference to the band Pink Floyd and their iconic album "The Dark Side of the Moon" (La Cara Oculta de la Luna in Spanish, where Cara can mean "face"), it’s also a playful nod to Rosa Huguet, the study’s lead author, as "Rosa" translates to "pink" in Spanish.

The facial fragment was discovered among a vast collection of approximately 6,000 fossil remains, including animal bones bearing cut marks. The location of the Homo aff. erectus fossil is less than 820 feet (250 meters) from the site where Homo antecessor remains were found. However, the Homo aff. erectus fragment predates the Homo antecessor remains by roughly half a million years. This significant temporal gap suggests that the face fragment belonged to an early human that predated the Homo antecessor remains. This temporal separation provides vital insights into the patterns of hominin migration and evolution.

José María Bermúdez de Castro, a paleoanthropologist at CENIEH and another co-author of the paper, highlighted the implications of this discovery for our understanding of European population dynamics. “It’s evident that about one million years ago there was a replacement in the European population,” he explained. "A species, possibly related to Homo erectus, would have given way to Homo antecessor."

Comparative analysis of the facial features of Homo aff. erectus and Homo antecessor reveals significant differences. María Martinón-Torres, a researcher at Centro Nacional de Investigacíon sobre la Evolución Humana, noted that Homo aff. erectus possesses more primitive facial features, particularly in the cheek region, compared to Homo antecessor. The mid-face region of Homo antecessor, in contrast, exhibits characteristics that more closely resemble those of modern humans (Homo sapiens). Specifically, while the faces of Homo sapiens and Homo antecessor are relatively vertical and flat, the face of Homo aff. erectus projects forward, a trait reminiscent of Homo erectus specimens. This difference in facial structure further supports the classification of the fossil as related to, but potentially distinct from, Homo erectus. The team emphasizes their caution in definitively labeling the individual Homo erectus due to the possibility that it might represent an entirely new species.

The discovery raises numerous questions that the research team hopes to answer through further investigation. Their immediate priority is to unearth more fossils that can shed light on the identity of Homo aff. erectus, its relationship to other hominin species, and the reasons why this population was eventually replaced by Homo antecessor. According to Martinón-Torres, the population represents a "snapshot" of the human groups that entered Europe during periods of favorable climatic conditions.

Martinón-Torres also emphasized the significance of the find in the broader context of hominin evolution, stating that the populations documented are "different from the earliest hominins that have been documented outside Africa." She drew a comparison to the Dmanisi hominins from Georgia, suggesting that the newly identified human group occupies "somewhere in an evolutionary space in between the earliest hominins found outside Africa – represented by the Dmanisi hominins – and Homo antecessor." Although the team cannot confirm the specimen is Homo erectus, it is the closest discovery to Homo erectus yet found in Europe.

Beyond this discovery, recent advancements in paleoanthropology continue to reshape our understanding of human origins. Parallel research has uncovered evidence of similar behaviors in Neanderthal and early modern human groups inhabiting the Levant approximately 100,000 years ago, long after the disappearance of both Homo aff. erectus and Homo antecessor. The interbreeding between Neanderthals and Homo sapiens has left a lasting legacy in the form of Neanderthal DNA present in our genomes.

The team is now planning to excavate deeper into the lower layers of the Sima del Elefante site, where the Homo aff. erectus face was found. This discovery underscores the extraordinary diversity of hominin species that inhabited even a relatively small region like Western Europe during the Pleistocene epoch. Despite the vast time spans separating these groups, their presence highlights the intricate and dynamic nature of human evolution.

While this discovery doesn’t definitively answer all the questions surrounding our evolutionary origins, it adds another layer of complexity to the ever-evolving narrative of our species. The emergence of Homo sapiens is a result of a complex story involving multiple hominin groups, each contributing to the development of our species and its eventual global dominance.