The study of human evolution continues to uncover new insights into the development of early humans and their migration patterns across the globe. A recent paper published in the Journal of Human Evolution on November 20, 2024, has revealed that the age of a pivotal Homo erectus cranium found at Gongwangling, Lantian County, Shaanxi Province, China, is likely much older than previously thought. This discovery, made by a collaborative team of Chinese and British scientists, has important implications for understanding human evolution, particularly the movement and dispersal of early hominins in Asia.
The fossil in question, the Lantian Homo erectus cranium, was first discovered in 1964, and for many years, its age was estimated to be around 1.15 million years ago. However, the new research suggests that the cranium is actually about 1.63 million years old, making it the oldest known hominin cranium in northeast Asia. This new dating not only places the cranium as the second-oldest known cranial remains outside of Africa but also offers important evidence about the migration of early hominins into Asia.
The new age estimate for the Lantian cranium significantly alters our understanding of the timeline for the movement of hominins out of Africa. The research team, which included scientists from the Guangzhou Institute of Geochemistry at the Chinese Academy of Sciences, the University of Exeter in the United Kingdom, and the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, used a variety of advanced techniques to refine the age of the fossil. These methods included loess-palaeosol stratigraphy, sedimentology, geochemistry, palaeomagnetism, and rock magnetic methods. Over a period of 12 years, from 2001 to 2013, the team carefully investigated key geological sections from the Gongwangling and Jiacun sites in the Lantian Basin of North China. By measuring thousands of samples and analyzing the geological context, the team was able to provide compelling evidence that the fossil is older than originally thought.
One of the key findings that led to the revised age estimate was the recognition that the fossil horizon could not be attributed to the previously assumed 15th loess unit (L15). Instead, the fossil was found to lie below L15, beneath an underlying erosional surface, indicating that there is a stratigraphic break between L15 and the hominin horizon. This change in the stratigraphic understanding was one of the first pieces of evidence that pointed to a significantly older age for the fossil.
In addition to the revised stratigraphy, the researchers also identified other factors that support the new age of 1.63 million years. For example, the fossil horizon corresponds to the time period between the Gilsa Event (around 1.62 million years ago) and the Olduvai Subchron (which ends at approximately 1.77 million years ago) in the geomagnetic time scale. The researchers also discovered that the same type of subtropical faunal assemblage found at the Gongwangling site was present in the Jiacun site, positioned in the same stratigraphic layers (S22–S23), further supporting the revised dating. Finally, the researchers used the Chinese loess-palaeosol sequence, which has a known relationship with the marine oxygen isotope stages, to place the fossil’s age at approximately 1.63 million years, a period of warm climatic conditions.
This new age for the Lantian cranium has profound implications for our understanding of the migration and dispersal of early humans. The revised dating suggests that small-brained hominins, such as the Homo erectus from Lantian, rapidly moved eastward from Africa during a warm period shortly after 1.75 million years ago. This aligns with other fossil evidence from sites much further south, such as in Indonesia, where fossils dating to around 1.5 to 1.6 million years ago have been found. This evidence suggests that early hominins may have followed both northern and southern dispersal routes into Asia, expanding our understanding of the routes taken by Homo erectus as they spread out of Africa.
The implications of this study are not limited to the Lantian cranium alone. The new dating of the Gongwangling site also provides valuable insight into the broader context of early human evolution, particularly the migration patterns of early hominins in Asia. As Robin Dennell, one of the lead researchers from the University of Exeter, points out, the revised age of the Lantian cranium establishes the Gongwangling site as a crucial benchmark for understanding the origin, migration, and dispersal of early humans in the Old World. This new knowledge encourages further re-evaluation of other early and controversial human fossils in China and Java, as their dating and significance might now need to be reassessed in light of the new findings at Gongwangling.
Another important aspect of the research is the role of the Chinese loess-palaeosol sequence in understanding early human evolution and global climate change during the Quaternary period. The loess-palaeosol sequence, which spans a period of 2.5 million years, provides a valuable archive for reconstructing past climates and the environments in which early hominins lived. The Gongwangling fossil’s new age, supported by the fine correlation between the loess strata and marine oxygen isotope stages, underscores the importance of this geological record in studies of both human evolution and global climate change during the last two million years.
The new findings at Gongwangling are significant not only for their contribution to the understanding of early human evolution but also for the way in which they enhance our understanding of the broader history of hominin dispersal across the globe. With this updated dating, the Lantian Homo erectus cranium becomes a critical piece of the puzzle in our understanding of how early humans migrated, adapted, and evolved over time. The research emphasizes the need for continued interdisciplinary collaboration and the application of advanced techniques to refine our understanding of human origins.
The collaborative nature of the study is also worth noting. The research team’s expertise, combining paleontological, geological, and geochemical methods, illustrates how scientific advances in one field can provide new insights into another. By combining knowledge from various disciplines, the team was able to approach the Lantian fossil from multiple angles and uncover a more accurate picture of its age and significance.
As Professor Huang Weiwen from the IVPP in Beijing explains, the revised age of the Gongwangling cranium is consistent with the geological context and the subtropical fossil fauna found at the site. The small brain size of the Lantian Homo erectus, similar to other early hominins from Georgia and Indonesia, also reinforces the idea that this population of Homo erectus was part of an early wave of human dispersal across Asia. The fossil provides further evidence that early humans were capable of adapting to diverse environments as they spread out of Africa and into other parts of the world.
The revised dating of the Gongwangling cranium is part of a broader effort to rewrite the history of human evolution. As more fossils are discovered and more advanced techniques are employed to analyze them, our understanding of the migration, adaptation, and development of early humans continues to evolve. The Lantian fossil, with its new age estimate, will undoubtedly continue to serve as a vital reference point in this ongoing effort, helping to refine the timeline of human evolution and offer new insights into the early history of our species.