The Red Deer Cave people were a group of early humans whose bones have been dated to between about 17,830 and 11,500 years ago. These remains were found in Red Deer Cave (also called Maludong) and Longlin Cave in Yunnan and Guangxi Provinces in Southwest China.
The bones show a mix of features that are both ancient and modern. Scientists have suggested different possibilities for their origins, including that they might be a late group of an older human species, a mix of Denisovans and modern humans, or that their features were misinterpreted. A study of their DNA in 2022 found they were likely modern humans related to people living in East and Southeast Asia today, as well as in the Americas. However, this finding was later questioned because the DNA might have been contaminated by modern human DNA. A response in 2025 argued against this possibility.
Evidence shows that large deer were cooked in the Red Deer Cave, which is how this group got their name.
Discovery and dating
In 1979, a petroleum geologist named Li Changqing found a block of fine-grained sediments with human remains, animal fossils, charcoal, and burnt clay in a cave near De'e, Longlin County, Guangxi Province, China. These remains were classified as a single specimen called LL-1. He quickly sent them to Kunming, Yunnan Province, for further study. There, scientists removed a mandible (lower jawbone) and some body bones. In 1989, human remains were also found during an excavation at the Red Deer Cave near Mengzi City, Yunnan Province. Researchers did not fully understand the importance of these discoveries until 2008, when Darren Curnoe, Ji Xueping, and their team began studying and dating East Asian human fossils to better understand the poorly documented Asian archaeological record. They found that the Red Deer Cave and Longlin people had a mix of modern and ancient traits, yet lived much more recently than expected. Charcoal inside the braincase of Red Deer Cave specimens was dated using uranium–thorium dating to between 17,830 and 13,290 years ago, and LL-1 was dated to about 11,510 years ago. Scientists restarted excavations at Longlin Cave in 2008, finding a few more fossils, but most of the material from the cave was already recovered during the first dig. In 2010, they successfully removed the rest of the skull and body fossils from the Red Deer Cave block.
The dating of these bones has caused confusion among scientists. Before DNA testing, the anatomy of the bones suggested they were archaic humans, like early Homo erectus or Homo habilis, who lived around 1.5 million years ago in Africa. In 2013, Curnoe, Ji, and their team proposed that the cave people might represent a new species. In 2015, they suggested the Red Deer Cave people may be a hybrid group, combining traits of early modern humans and one or more unknown ancient species. This mix of features is not seen in any other known specimen. Modern humans may have arrived in China as early as 130,000 years ago, as shown by the Zhirendong remains, but the classification of such early remains is debated due to their unusual anatomy. Later that year, they concluded the femur (thigh bone) of the Red Deer Cave people is far outside the range of variation seen in modern humans, suggesting they were archaic. They proposed they might be related to the Denisovans, a poorly understood group of ancient humans in Asia, or a long-lost lineage from an early human migration out of Africa that had not developed a typical human body structure, like the Dmanisi hominins. This possibility has also been suggested for Homo floresiensis, a small human species that survived recently on the island of Flores. Scientists speculated the Red Deer Cave people may have survived for a similar reason, remaining isolated in mountainous regions.
Anatomy
The fossils of the Red Deer Cave dwellers are relatively young but show features that are similar to early humans. These people had unique characteristics that differ from modern humans, such as a flat face, wide nose, a jaw that sticks out without a chin, large molars, thick eyebrows, strong skull bones, and a brain that was medium in size. Their body size was also smaller than that of modern humans, with an estimated weight of 50 kg (110 lb). These traits were unusual compared to the range of variation seen in other human fossils from the Late Pleistocene era.
Earlier research by Curnoe showed that the bones and teeth of these individuals were very similar to those of early humans. The height of the mandibular symphysis (the middle part of the lower jaw) measured 27.7 mm (1.09 in), which is within the range of modern humans. The thickness of this area was 12.5 mm (0.49 in), a measurement found in Neanderthals and Middle Palaeolithic modern humans. The mental foramina (holes in the jawbone) were located lower than usual, at 26.9 mm (1.06 in) from the base, compared to modern humans and Neanderthals, which are typically above 30 mm (1.2 in). The height and thickness of the first two molars were nearly identical to those of Upper Palaeolithic Asians, but the molars themselves were broader, similar to those of Neanderthals or Middle Palaeolithic humans.
The femur (thigh bone) of the Red Deer Cave dwellers shows very old traits that are not found in modern humans. The subtrochanteric region (the area just below the lesser trochanter) is circular in shape and has less bone material, making it weaker against straight-down forces. The middle part of the femur is narrow, which may suggest the individual was short-statured. The femur also has a moderate pilaster value index (a measure of the strength of the femur's ridge), which is much lower than that of modern humans. Overall, the femur is similar to those of much older Lower Pleistocene Homo fossils.
The reconstruction of the Maludong femur confirmed it was very small. The outer layer or walls of the femur are very thin. The areas of the femur that experience high stress and the femur neck are longer than usual. The part of the femur where the primary hip flexor muscle (the lesser trochanter) attaches is strong and faces strongly backward.
Classification and archaeogenetics
Scientists initially thought the Red Deer Cave people might be a very old group of humans, but they were hesitant to call them a completely new or unknown species. The remains found in Red Deer Cave show physical similarities to older human groups like Homo erectus and Homo habilis. In particular, the Red Deer Cave specimen (RDC) was most similar to a 1.89-million-year-old Homo erectus individual called KNM-ER 1481, who lived in Africa. Some features of the RDC remains also resemble those of Australopithecus, a group older than the Homo genus. Researchers also considered the possibility that the remains resulted from mixing between Denisovans and modern humans, or that they belonged to a group of modern humans with unusual physical traits.
One theory suggested that the Red Deer Cave people lived in the region over 100,000 years ago and became isolated due to the area’s geography. High mountains and deep valleys can separate species, allowing them to develop unique traits over time. The environment in Southwest China is also unique because of the uplift of the Qinghai-Tibetan Plateau.
In July 2022, scientists successfully sequenced ancient DNA from the skull of the Red Deer Cave specimen, known as Mengzi Ren (MZR). This DNA showed that the individual was part of a group of anatomically modern humans closely related to ancient Southern East Asians. The MZR specimen also shared genetic similarities with modern East Asians and, to a lesser extent, with Indigenous peoples of the Americas. This suggests that genetic traits similar to MZR may have been passed to the ancestors of Native Americans before they became isolated in Beringia. The MZR individual belonged to a genetic group called haplogroup M9, which originated in South Asia about 47,000–50,000 years ago. Later studies, however, questioned the connection between MZR and Native American populations.
Remains from the Longlin Cave in Guangxi belong to a different group called the "Longlin lineage" or "Guangxi ancestry." This group is distinct from the MZR specimen. The Longlin lineage is closely related to both ancient northern and southern East Asian groups but is more closely connected to them than to older East Asian groups like the Tianyuan, Hoabinhian, and Andamanese populations. The Longlin lineage also shares genetic similarities with the Jōmon people of Japan, who are similarly related to both northern and southern East Asian groups. This suggests the Longlin and Jōmon lineages separated from the main East Asian group around the same time. However, the Longlin and Jōmon lineages have different genetic relationships with other groups. A 2025 study found that the Longlin lineage likely formed from a mix of two groups: one related to an older Asian population (Xingyi_EN) and another related to southern East Asians (Qihe3-like).
Although the Longlin lineage does not appear to be present in modern populations, a 9,000-year-old individual from the Dushan Cave had about 17% genetic traits from the Longlin lineage, with the rest coming from a group similar to ancient people from Fujian. This "Dushan ancestry" was also found in people from Mainland Southeast Asia 8,300 to 6,400 years ago, who had about 72% Dushan traits and 28% from a group linked to the Hoabinhian culture. This ancestry may be connected to early speakers of the Austroasiatic language. More recently, Austroasiatic speakers have been linked to a newly discovered genetic group from Central Yunnan (Xingyi_LN), which is closely related to both ancient northern and southern East Asians but is distinct from them.