Researchers in Spain have unearthed a fragmented hominin face, believed to be over 1.4 million years old, at the Sima del Elefante cave site in Atapuerca. This fossil, consisting of a maxilla (upper jawbone) and cheekbone, represents the oldest known hominin fossil found in Europe and potentially pushes back the earliest evidence of human ancestors on the continent by 200,000 years. The discovery provides crucial insight into the early evolution of the human face and the dispersal of hominins across Eurasia, although its specific lineage remains to be determined through further study. The researchers suggest this finding might be related to a hominin jawbone found at the same site in 2007 and dated to 1.2 million years ago, potentially representing a single evolutionary lineage.
Giant tunnels known as "paleoburrows" in South America, some exceeding a meter in diameter and tens of meters long, were likely dug by giant extinct ground sloths (specifically, scelidotheriines and mylodontines). Researchers used a variety of evidence, including claw marks, sediment analysis, and the burrows' size and shape, to rule out other potential excavators such as armadillos or humans. These immense burrows, which represent the largest ichnofossils (trace fossils) on the continent, provide insight into the behavior and ecology of these megafauna and demonstrate a unique adaptation not seen in extant sloths.
HN commenters discuss the likelihood of the giant paleoburrows being created by giant ground sloths, expressing skepticism due to the sheer size and complexity of some tunnels. Several suggest the possibility of multiple generations of sloths expanding the burrows over time, while others question the practicality of such large burrows for creatures needing to escape predators. The lack of claw marks in some sections is noted, prompting speculation about other unknown extinct creatures or even geological processes. Some commenters focus on the implications for understanding megafauna and past ecosystems, highlighting the surprising scale of these ancient burrows and the need for further investigation. One commenter humorously links the lack of clear answers to the enduring mysteries of Göbekli Tepe.
Summary of Comments ( 35 )
https://news.ycombinator.com/item?id=43455251
Hacker News users discuss the discovery of a million-year-old human facial fragment, expressing excitement about the implications for understanding human evolution. Some question the certainty with which the researchers assign the fossil to Homo erectus, highlighting the fragmented nature of the find and suggesting alternative hominin species as possibilities. Several commenters also discuss the significance of Dmanisi, Georgia, as a key location for paleoanthropological discoveries, and the potential for future finds in the region. Others focus on the methodology, including the use of 3D reconstruction, and the challenges of accurately dating such ancient specimens. A few highlight the persistent difficulty of defining "species" in the context of evolving lineages, and the limitations of relying on morphology alone for classification.
The Hacker News post titled "Fragment of a human face aged over one million years discovered" (linking to a Science Daily article about a hominin facial fragment found in Spain) has several comments discussing the discovery's significance and implications.
Several commenters express excitement and wonder at the find, highlighting the vast timescale involved and the implications for understanding human evolution. One commenter reflects on the sheer length of time represented by a million years, emphasizing the numerous generations and evolutionary changes that have occurred since. Another notes the remarkable preservation of the fossil, considering its age.
A recurring theme in the comments is the ongoing debate and changing understanding of human lineage. Commenters discuss the complexity of the hominin family tree and how this new discovery might fit into it. Some highlight the difficulty of definitively placing such fragments within specific species, acknowledging the ongoing research and revisions within paleoanthropology. One user points out the fragmented nature of the fossil record and how each new discovery adds a piece to the puzzle but also potentially raises new questions.
Several commenters discuss the specific characteristics of the fossil, including its robust features, and speculate about the environment and lifestyle of the hominin it belonged to. There's discussion around the features that distinguish it from other known hominins of the period. Some comments delve into the possible relationship of this find to other hominin species found in the region, suggesting potential ancestral connections.
Some comments also touch on the methodology of paleoanthropology, including dating techniques and the process of reconstructing facial features from fragmented remains. There's a brief exchange about the reliability of such reconstructions and the potential for artistic interpretation.
Finally, a few commenters express hope for future discoveries and further research that could shed more light on this period of human evolution. The overall sentiment in the comments is one of fascination and curiosity about the deep history of humanity and the ongoing quest to understand our origins.