Archaeologists have discovered a new human rib specimen in the White Cliff Cave, one of two sites known to have been inhabited by Denisovans. Dating from 48,000 to 32,000 years ago, the specimen also belongs to the Denisovan lineage and indicates that the caves were present into the Late Pleistocene.
Portrait of a young Denisovan woman based on a skeletal profile reconstructed from an ancient DNA methylation map. Image courtesy of Maayan Harel.
The Denisovans are an extinct human group first identified from a genome sequence determined from a finger bone fragment found in the Denisova Cave in the Altai Mountains of southern Siberia.
Subsequent genomic analyses revealed that the Denisovans diverged from Neanderthals 400,000 years ago, and that at least two distinct Denisovan populations interbred with the ancestors of modern Asians.
In 2019, a 160,000-year-old jawbone discovered in Baishiyi Cave, a limestone cave on the northeastern edge of the Tibetan Plateau, was identified as being of Denisovan origin.
In 2020, archaeologists found Denisovan mtDNA in deposits from the cave, suggesting they were present around 100,000 years ago, 60,000 years ago, and possibly 45,000 years ago.
The new Denisovan rib, discovered in the Baishigai Karst Cave, dates to approximately 48,000 to 32,000 years ago.
“The combined fossil and molecular evidence indicates that the Amaka Basin, where the Baishiqai Cave is located, was a relatively stable environment for the Denisovans, despite its high altitude,” said Dr Frid Welker, an archaeologist at the University of Copenhagen.
“The question now is, when and why did the Denisovans on the Tibetan Plateau become extinct?”
In their study, Dr Welcker and his colleagues examined more than 2,500 bones discovered in the White Cliff Cave.
“We know that the Denisovans hunted, butchered and ate a wide range of animal species,” said Dr Geoff Smith, a zooarchaeologist at the University of Reading.
“Our study reveals new information about Denisovan behavior and adaptation to high-altitude environments and a changing climate.”
“We are only just beginning to understand the behavior of this incredible human species.”
The bone remains found in the Baixa Karst caves were broken into many fragments, making them difficult to identify.
The researchers used a new scientific technique that uses differences in bone collagen between animals to determine which species the bone remains belong to.
“Zooarchaeology by mass spectrometry (ZooMS) allows us to extract valuable information from bone fragments that are often overlooked, providing deeper insights into human activities,” said Dr Huan Xia, a researcher from Lanzhou University.
Scientists have determined that most of the bones belong to blue sheep called bharals, as well as wild yaks, horses, the extinct woolly rhinoceros and spotted hyenas.
Bones from small mammals, such as marmots, and birds were also identified.
“Current evidence suggests that it was the Denisovans, and not other human groups, who lived in caves and made effective use of all available animal resources during their occupation,” said Dr Jiang Wang, also from Lanzhou University.
“Detailed surface analysis of the bone fragments shows that the Denisovans removed the meat and marrow from the bones, but also suggests that humans used them as raw material for making tools.”
This study paper In the journal Nature.
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H. Shea othersMiddle and Late Pleistocene Denisovan life in the Baishi Cliff karst caves. NaturePublished online July 3, 2024; doi: 10.1038/s41586-024-07612-9
Source: www.sci.news
