19 December 2019 00:41
New 1.5 million-year-old Homo erectus maxilla from Sangiran (Central Java, Indonesia). Provenience reassessment of the 1931–1933 Ngandong Homo erectus (Java), confirmation of the bonebed origin reported by the discoverers. P. The Ngandong Fossil Hominids: A Comparative Study of a Far Eastern Homo erectus Group Yale University Publications in Anthropology 78 (Yale Peabody Museum, 1980). P. The Evolution of Homo erectus: Comparative Anatomical Studies of an Extinct Human Species (Cambridge Univ. Gamma-ray spectrometric dating of late Homo erectus skulls from Ngandong and Sambungmacan, Central Java, Indonesia.
The age of the 20 meter Solo River terrace, Java, Indonesia and the survival of Homo erectus in Asia. Rediscovery of the Homo erectus bed at Ngandong: site formation of a late Pleistocene hominin site in Asia. Mass death and lahars in the taphonomy of the Ngandong Homo erectus bonebed, and volcanism in the hominin record of eastern Java. Faunal taphonomy and biostratigraphy at Ngandong, Java, Indonesia and its implications for the late survival of Homo erectus. Paleoanthropology 2012, abstr.
It reached Java more than 1.5 million years ago, and the new dates suggest it died out at least 35,000 years before the arrival there of our own species, Homo sapiens. Professor Russell Ciochon holds a cast of a Homo erectus skull (Tim Schoon/University of Iowa via AP) Homo erectus may have been doomed on Java by climate change that turned its open woodland environment into rainforest, Mr Ciochon said. The groundbreaking discovery also confirms that Homo erectus was the most long-lived human species – thriving for at least nearly two million years. Professor Russell Ciochon of the University of Iowa said: 'This site is the last known appearance of Homo erectus found anywhere in the world. Homo erectus evolved almost two million years ago and archaeological records show they spread across Asia over an area ranging from Turkey to China.
More than 25,000 fossil specimens were buried in the river mud in an area called Ngandong, including 12 skull caps and two leg bones from a particularly intriguing human ancestor: Homo erectus. Efforts to determine the exact age of the Java fossils didn't help much, since that gave a broad range of options: Their time of death was estimated to be somewhere between 550,000 and 27,000 years ago. The results showed that the Homo erectus individuals perished in a mass death between 117,000 and 108,000 years ago. That means the bones represent the last known appearance of Homo erectus in the archaeological record. A side view of one of the Homo erectus skull caps discovered in Ngandong, Indonesia. The new timeline helps solve other puzzles as well, since it enables anthropologists to identify other ancient human species that Homo erectus overlapped with — and those it didn't. "Our research shows that Homo erectus did not survive late enough to interact with modern humans on Java," Russell Ciochon, a co-author of the new study, told Business Insider. "Ngandong is the youngest known Homo erectus site in the world." According to the study authors, the skulls caps and leg bones discovered in Ngandong represent the largest Homo erectus find at any single site. Ciochon/University of Iowa That's because the bones, along with 25,000 other fossils that were later lost during World War II, "accumulated within a log jam in the river," according to study co-author Kira Westaway. Ciochon said his team isn't sure how these particular individuals died, but one theory about why Homo erectus died out on Java overall may sound familiar: climate change. "The demise of Homo erectus on Java coincides with this rainforest expansion, and the changing environment likely contributed to the demise," Ciochon said. By correctly dating these fossils, anthropologists can now explore who Homo erectus might have interacted with before they died out. The list is large: Homo erectus could have interbred with Denisovans — another group of human ancestors found mostly in Siberia and east Asia — as well as two other early human species that lived on Pacific islands, called Homo floresiensis and Homo luzonensis. erectus," Ciochon said, given that the new date from his new study falls solidly within the time frame that Denisovans were alive. But it's not clear whether Denisovans and Homo erectus intermixed on Java in particular. "There is considerable speculation about where and when the Denisovans meet Homo erectus and what the results of those interactions were," Ciochon added. This new discovery also opens up the possibility that the two other east Asian ancestor species descended from Homo erectus. Ciochon and Westaway's new research cements Homo erectus' status as one of the longest-lived early humans. The first Homo erectus specimen was discovered in Indonesia in 1891, and fossils have been found across Africa and in China. He added that it's possible other Homo erectus populations outlived the counterparts found at the Java site. Skulls from central Java may come from the last surviving population of Homo erectus, suggests a new study dating the fossil bed and the surrounding landscape. University of Iowa anthropologist Russell Ciochon and his colleagues dated fossils and sediment layers from a site called Ngandong in a naturally terraced valley carved out of the surrounding hills by the Solo River. In a bid to make sense of it all, Ciochon and his colleagues used uranium-series dating on some newly excavated mammal fossils from the same layer as the Homo erectus skulls. To piece together the whole area's geological history and see how it might relate to the Homo erectus fossils, they also used other dating methods on sediment and rocks from Ngandong and other sites in the river valley. The results suggest that the bone bed (and therefore the collection of Homo erectus fossils) is between 117,000 and 108,000 years old. That makes Ngandong the last-known trace of Homo erectus in the world. "There is always a possibility that someone will find new Homo erectus evidence that is younger and therefore that becomes the last appearance—but this is science! At present, we make an interpretation based on the evidence that we have, and this is that Ngandong represents the last appearance of Homo erectus," Westaway told Ars. "Our work provides the age of the last-known appearance of Homo erectus, but this does not mean that it is the age of extinction," Ciochon told Ars. "Small groups of Homo erectus may have lived longer without leaving fossil evidence. The Ngandong dates also strongly suggest that Homo erectus may have gone extinct, at least in Indonesia, long before our species made it that far. "This older species is likely Homo erectus," Ciochon told Ars. Our dates support the genetic evidence that Homo erectus could have interbred with the Denisovans."