The settlement of Europe could be the result of several immigration waves by a single population

The settlement of Europe could be the result of several immigration waves by a single population

The CENIEH conducts the morphological and metric analysis of the lower molars in the mandible from Montmaurin-La Niche (France) using micro-computed tomography, to study the origin of the Neanderthals.
settlement Europe immigration population
Montmaurin-La Niche mandible/M. Martínez de Pinillos

The Dental Anthropology Group of the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), in collaboration with the paleoanthropologist Amélie Vialet of the Muséum National d’Histoire Naturelle (MNHN) in Paris, has just published a detailed external and internal study of the molars in the mandible from the French site of Montmaurin-La Niche in the Journal of Human Evolution, whose results strengthen the hypothesis that the settlement of Europe could have been the result of several waves of migration at different times by a common source population.

The aim in this paper, led by the researchers Marina Martínez de Pinillos (CENIEH) and Laura Martín-Francés (CENIEH and PACEA-University of Bordeaux), is to shed light on the origin of the Neanderthals. The latest data obtained from paleontological and geomorphological studies place the Montmaurin-La Niche mandible in a chronologically intermediate position between the fossils of the Middle Pleistocene and the Neanderthals.

The micro-computed axial tomography (microCT) technique has enabled the molars in this mandible to be compared with the external and internal structures of over 400 other molars from the European, Asian and African Pleistocene and Holocene.

This exhaustive metric and morphological analysis has revealed that, while the mandible is more closely related to African and Eurasian populations from the Early and Middle Pleistocene, the enamel and dentine morphology and pulp cavity proportions are similar to those in Neanderthals. “Nevertheless, the absolute and relative enamel thickness values (2D and 3D) show greater affinity with those exhibited by certain Early Pleistocene hominins”, says Martínez de Pinillos.

Possible hybridization

Over recent decades, finds of human fossil remains from the European Middle Pleistocene have prompted the debate on the evolutionary scenario of the genus Homo on that continent to be reopened. “The great variability we find among the European Middle Pleistocene fossils cannot be ignored in studying human evolution on our continent”, states Martín-Francés.

This variability in European Middle Pleistocene populations could indicate different migrations at different times and/or fragmentation of the population, thought it might also be due to possible hybridization between residents and new settlers.

Montmaurin-La Niche mandible/M. Martínez de Pinillos

Full bibliographic information

Martínez de Pinillos, M., Martín-Francés, L., Bermúdez de Castro, J. M., García-Campos, C., Modesto-Mata, M., Martinón-Torres, M., & Vialet, A. (2020). Inner morphological and metric characterization of the molar remains from the Montmaurin-La Niche mandible: the Neanderthal signal. Journal of Human Evolution, 145, 102739. doi: 10.1016/j.jhevol.2019.102739.
Press release on the settlement of Europe due to immigration waves from a common source population from CENIEH

molars Sima de los Huesos

The molars from Sima de los Huesos site share dental tissue traits with Homo antecessor and Neanderthals

The molars from Sima de los Huesos site share dental tissue traits with Homo antecessor and Neanderthals

The Dental Anthropology Group from CENIEH publishes a paper in PLOS ONE in which microscopy and micro-computed tomography are used to study the dental tissues in molars from European Middle Pleistocene individuals found at this site in Atapuerca, and compares these with species from the fossil record and modern humans
Distribution of enamel thickness in a lower molar from Sima de los Huesos compared with H. antecessor, Tighenif specimen and modern human. Credits: Martín-Francés et al.

The Dental Anthropology Group of the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) has published a paper this week in the journal PLOS ONE which marks another step forward in characterizing the individuals from the Sima de los Huesos site (Atapuerca, Burgos, Spain) and their relationship with Neanderthals and Homo antecessor, and helps to clarify the evolutionary steps that led to the dentition characteristic of Late Pleistocene hominins.

In this paper, whose lead author is the researcher Laura Martín-Francés (CENIEH and PACEA-University of Bordeaux), the dental tissues in the molars of the European Middle Pleistocene individuals found at Sima de los Huesos are analyzed, and compared with species in the fossil record and modern humans.

To conduct this comparative study, micro-computed tomography (mCT) and high-resolution images were used to examine the internal structure of 72 upper and lower molars from this site at Atapuerca, and these were contrasted against another 500 molars belonging to species from the genus Homo, extinct and extant, from Africa, Asia and Europe.

In the entire fossil record analyzed, only the Neanderthals present a unique structural pattern in molar tissues (enamel thickness, percentage of tissues and their distribution in the crown) which, in addition, they do not share with any other species. “In comparison with that record and with modern humans, Neanderthals had thin enamel, with a higher proportion of dentine and a more disperse distribution pattern”, says Martín-Francés.

It has been possible to determine that the molars from the Sima de los Huesos individuals had thick enamel and that, therefore, they do not share this trait with Neanderthals. Nevertheless, the two groups do share the same tissue distribution pattern.

“The results suggest that even though the complex of typically Neanderthal traits appeared later, certain aspects of the Neanderthal molar structure were already present in the hominins from Sima de los Huesos. In earlier work, we had identified this same pattern in Homo antecessor, another of the species recovered at Atapuerca”, adds Martín-Francés.

The Sima de los Huesos population, related genetically to the Neanderthals, represents a unique opportunity to study the appearance of the “typical” structural pattern of Neanderthal molar tissue.

Distribution of enamel thickness in an upper molar from Sima de los Huesos compared with H. antecessor, Neanderthal and modern human. Credits: Martín-Francés et al.

Full bibliographic information

Martín-Francés, L., Martinón-Torres, M., Martínez de Pinillos, M., García-Campos, C., Zanolli, C., Bayle, P., Modesto-Mata, M., Arsuaga, J. L., & Bermúdez de Castro, J. M. (2020). Crown tissue proportions and enamel thickness distribution in the Middle Pleistocene hominin molars from Sima de los Huesos (SH) population (Atapuerca, Spain). PLoS ONE, 15(6), e0233281. doi: 10.1371/journal.pone.0233281.
Press release from CENIEH

Cueva de los Toriles

Cueva de los Toriles site is dated to the Early-Middle Pleistocene by the presence of a primitive badger

Cueva de los Toriles site is dated to the Early-Middle Pleistocene by the presence of a primitive badger

The CENIEH has led a paper on this archaeological site located in Castilla-La Mancha (Spain), which makes clear its importance as one of the most significant enclaves with fossil remains from these chronologies in the southern Iberian plateau

Badger teeth. Credits: Daniel García Martínez

A team of researchers headed by Daniel Garcia Martínez, a paleoanthropologist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has just published a paper in the Journal of Iberian Geology on some remains of a primitive badger found in the Cueva de los Toriles (Carrizosa, Ciudad Real, Spain) which have allowed it to be dated to the Early-Middle Pleistocene: this archaeological site could potentially be a singular enclave with fossil remains from the southern Iberian plateau in these chronologies.

Even though there is currently no exact dating for the sedimentary deposits at this site in La Mancha, the finding of two lower molars of a mustelid, attributed to the species Meles cf. thorali, a primitive badger, has enabled their potential age to be checked, because this extinct mustelid is principally found in sites around 1 million years old.

As Alberto Valenciano, a specialist in mustelids from the University of Cape Town, explains: “In accordance with the presence of this badger species in the cave, we can tentatively assume an age ranging from the Late Pliocene up to the Middle Pleistocene”. In addition, as García Martínez comments: “These chronologies would be consistent with certain lithic tools recovered from the site”.

A natural corridor

Studying the southern Iberian plateau is primordial to revealing the population and movement of fauna in the Iberian Peninsula, because it functions as a natural corridor connecting the Central System and Iberian Range to the north with the Baetic Ranges to the south.

Cueva de los Toriles
Cueva de los Toriles site. Credits: Danie García Martínez

In the southern Iberian plateau, there are far fewer Pleistocene sites than in the northern plateau, where sites of world importance such as Atapuerca (Burgos) are found, because the eminently agricultural use of the land has caused many open-air sites to be altered or vanish.

“And while it is true that certain sites well-known to archaeologists are found in Ciudad Real, such as Albalá or El Sotillo, these are rich in lithic remains but poor in fossils, something which does not happen at Cueva de los Toriles where remains of macromammals have also been found, which could help to fill the gaps in our knowledge about this region”, states García Martínez.

“This cave is also an important site because of the enduring human presence stretching back to prehistory which we are seeing in our first investigations. A major milestone in the archaeology of Castilla-La Mancha and the southern sub-plateau", says Pedro R. Moya Maleno, from the Universidad Complutense de Madrid.

 

Full bibliographic information

 

García-Martínez, D., Valenciano, A., Suárez-Bilbao, A., Palancar, C. A., Megía García, I., Moreno, D., Campaña, I., & Moya-Maleno, P. R. (2020). New remains of a primitive badger from Cueva de los Toriles (Carrizosa, Castilla-La Mancha, Iberian Peninsula) suggest a new quaternary locality in the southern Iberian plateau. Journal of Iberian Geology (0). doi: 10.1007/s41513-020-00127-y

Press release from CENIEH


Dentition enables the sex of the youngest individuals from Sima de los Huesos to be estimated

Dentition enables the sex of the youngest individuals from Sima de los Huesos to be estimated

In a new study of sexual dimorphism carried out by the Dental Anthropology Group at the CENIEH, where a total of 32 dental pieces were analyzed, it has been possible to determine the sex of the immature specimens found at this site situated in the Sierra de Atapuerca

dentition Sima de los Huesos sexual dimorphism
Teeth from Sima de los Huesos. Credits: Cecilia García Campos

Today the Journal of Human Evolution publishes a study on sexual dimorphism led by Cecilia García Campos, a researcher in the Dental Anthropology Group at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) in which, thanks to the analysis of 32 dental pieces using micro-computed tomography, it has been possible to rise to the challenge posed, by estimating the sex of at least 15 individuals from the population of Sima de los Huesos site in the Sierra de Atapuerca (Burgos, Spain).

The extraordinary fossil collection recovered at this Middle Pleistocene site offers a unique opportunity for conducting demographic studies of the populations inhabiting Europe during that period. Nevertheless, many of the individuals in the Sima de los Huesos population are sub-adults or young adults who had not completed their development, so that their skeletons do not present clear secondary sexual traits that could help to determine their sex.

By contrast, these traits can be detected in their dentition, as the lead author of this work explains: “The teeth form early, allowing us to suggest a sex assignment even in those individuals who have not come through adolescence, so that dental anthropology turns out to be a very useful tool when endeavoring to study past populations with demographic structures similar to that in Sima de los Huesos”.

Dental histology

By studying the dentition of modern populations, in 2018 the CENIEH Dental Anthropology Group managed to identify a characteristic histological pattern to distinguish the canines belonging to male individuals from those of female individuals, and which offers an efficacy of 92.3%.

The application of this pattern at Sima de los Huesos has not only enabled the sex estimations proposed in earlier studies to be ratified, but also to suggest a sex assignment for the youngest individuals in the sample, something which had not been possible in previous work. All of this, therefore, has made clear the usefulness of dental histology for the assessment of sexual dimorphism and estimating sex in modern and past human populations.

“Specifically, this tool is especially useful in paleoanthropological settings, in which the other bone structures usually appear fragmented or are absent, and above all in those where sub-adults are better represented in their demographic structures”, comments García Campos.

 

Full bibliographic information

 

García-Campos, C., Modesto-Mata, M., Martinón-Torres, M., Martínez de Pinillos, M., Martín-Francés, L., Arsuaga, J.L., Bermúdez de Castro, J. M. 2020. Sexual dimorphism of the enamel and dentine dimensions of the permanent canines of the Middle Pleistocene hominins from Sima de los Huesos (Burgos, Spain). Journal of Human Evolution

 

Press release from CENIEH


The African affinities of the southwestern European Acheulean

A study highlights the African affinities of the southwestern European Acheulean

The CENIEH is the co-leader of a paper published in the Journal of Paleolithic Archaeology which presents a synthesis of human occupation in the Iberian Peninsula Atlantic margin during the Early and Middle Paleolithic
African Acheulean
Porto Maior site (As Neves, Pontevedra). Credits: Eduardo Méndez

The Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) is the co-leader of a study published this week in the Journal of Paleolithic Archaeology which presents a synthesis of human occupation in the Iberian Peninsula Atlantic margin during the Early and Middle Paleolithic, and highlights the African affinities of Acheulean industry in southwestern Europe.

Over recent years, a team whose members include the CENIEH archaeologist Manuel Santonja, and Eduardo Méndez, leading author of the study trained at the CENIEH, has excavated and interpreted important archaeological sites on the banks of the Miño River, on both the Portuguese and Spanish shores, with singular Acheulean and Mousterian assemblages.

The chronology attributed to these sites, the second half of the Middle Pleistocene and the first part of the Late Pleistocene (between 50,000 and 400,000 years ago), and the characteristics of the knapped utensils recovered allow close parallels to be drawn with other regions of the Iberian Peninsula, and rule out any kind of time mismatch in these stages in the northwestern area, as had been proposed earlier.

Some of the sites excavated, and in particular the Acheulean one at Porto Maior (As Neves, Pontevedra), have produced unusual assemblages of large utensils, handaxes and cleavers, which make a decisive contribution to underlining the African affinities of that industry in the Iberian Peninsula and southwestern Europe, in contrast to Acheulean assemblages identified in the northernmost areas of the continent, where the distinctive technological features of the African Acheulean arrive less crisply defined.

 

Full bibliographic information

Méndez-Quintas, E., Santonja, M., Arnold, L. J., Cunha-Ribeiro, J. P., Xavier da Silva, P., Demuro, M., Duval, M., Gomes, A., Meireles, J., Monteiro-Rodrigues, S., & Pérez-González, A. (2020). The Acheulean technocomplex of the Iberian Atlantic margin as an example of technology continuity through the Middle Pleistocene. Journal of Paleolithic Archaeology (0). doi: 10.1007/s41982-020-00057-2.
Press release from CENIEH

Neanderthals and modern humans diverged at least 800,000 years ago

Neanderthals and modern humans diverged at least 800,000 years ago

Neanderthals and modern humans diverged at least 800,000 years ago, substantially earlier than indicated by most DNA-based estimates, according to new research by a UCL academic.

Neanderthals diverged teeth
Dental morphology. Credit: Aida Gómez-Robles

The research, published in Science Advances, analysed dental evolutionary rates across different hominin species, focusing on early Neanderthals. It shows that the teeth of hominins from Sima de los Huesos, Spain - ancestors of the Neanderthals - diverged from the modern human lineage earlier than previously assumed.

Sima de los Huesos is a cave site in Atapuerca Mountains, Spain, where archaeologists have recovered fossils of almost 30 people. Previous studies date the site to around 430,000 years ago (Middle Pleistocene), making it one of the oldest and largest collections of human remains discovered to date.

Dr Aida Gomez-Robles (UCL Anthropology), said: "Any divergence time between Neanderthals and modern humans younger than 800,000 years ago would have entailed an unexpectedly fast dental evolution in the early Neanderthals from Sima de los Huesos."

"There are different factors that could potentially explain these results, including strong selection to change the teeth of these hominins or their isolation from other Neanderthals found in mainland Europe. However, the simplest explanation is that the divergence between Neanderthals and modern humans was older than 800,000 years. This would make the evolutionary rates of the early Neanderthals from Sima de los Huesos roughly comparable to those found in other species."

Modern humans share a common ancestor with Neanderthals, the extinct species that were our closest prehistoric relatives. However, the details on when and how they diverged are a matter of intense debate within the anthropological community.

Ancient DNA analyses have generally indicated that both lineages diverged around 300,000 to 500,000 years ago, which has strongly influenced the interpretation of the hominin fossil record.

This divergence time, however, is not compatible with the anatomical and genetic Neanderthal similarities observed in the hominins from Sima de los Huesos. The Sima fossils are considered likely Neanderthal ancestors based on both anatomical features and DNA analysis.

Dr Gomez-Robles said: "Sima de los Huesos hominins are characterised by very small posterior teeth (premolars and molars) that show multiple similarities with classic Neanderthals. It is likely that the small and Neanderthal-looking teeth of these hominins evolved from the larger and more primitive teeth present in the last common ancestor of Neanderthals and modern humans."

Dental shape has evolved at very similar rates across all hominin species, including those with very expanded and very reduced teeth. This new study examined the time at which Neanderthals and modern humans should have diverged to make the evolutionary rate of the early Neanderthals from Sima de los Huesos similar to those observed in other hominins.

The research used quantitative data to measure the evolution of dental shape across hominin species assuming different divergent times between Neanderthals and modern humans, and accounting for the uncertainty about the evolutionary relationships between different hominin species.

"The Sima people's teeth are very different from those that we would expect to find in their last common ancestral species with modern humans, suggesting that they evolved separately over a long period of time to develop such stark differences."

The study has significant implications for the identification of Homo sapiens last common ancestral species with Neanderthals, as it allows ruling out all the groups postdating 800,000 year ago.

Neanderthals diverged teeth
Hominin teeth. Credit: Aida Gómez-Robles

Press release from University College London


Denisovans Tibetan Plateau Baishiya Karst Cave Xiahe mandible

First hominins on the Tibetan Plateau were Denisovans

First hominins on the Tibetan Plateau were Denisovans

Denisovan mandible likely represents the earliest hominin fossil on the Tibetan Plateau

Denisovans Tibetan Plateau Baishiya Karst Cave Xiahe mandible
The Xiahe mandible, only represented by its right half, was found in 1980 in Baishiya Karst Cave. Credit: © Dongju Zhang, Lanzhou University

So far Denisovans were only known from a small collection of fossil fragments from Denisova Cave in Siberia. A research team led by Fahu Chen from the Institute of Tibetan Plateau Research, CAS, Dongju Zhang from Lanzhou University and Jean-Jacques Hublin from the Max Planck Institute for Evolutionary Anthropology now describes a 160,000-year-old hominin mandible from Xiahe in China. Using ancient protein analysis the researchers found that the mandible’s owner belonged to a population that was closely related to the Denisovans from Siberia. This population occupied the Tibetan Plateau in the Middle Pleistocene and was adapted to this low-oxygen environment long before Homo sapiens arrived in the region.

Denisovans - an extinct sister group of Neandertals - were discovered in 2010, when a research team led by Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) sequenced the genome of a fossil finger bone found at Denisova Cave in Russia and showed that it belonged to a hominin group that was genetically distinct from Neandertals. "Traces of Denisovan DNA are found in present-day Asian, Australian and Melanesian populations, suggesting that these ancient hominins may have once been widespread," says Jean-Jacques Hublin, director of the Department of Human Evolution at the MPI-EVA. "Yet so far the only fossils representing this ancient hominin group were identified at Denisova Cave."

Mandible from Baishiya Karst Cave

In their new study, the researchers now describe a hominin lower mandible that was found on the Tibetan Plateau in Baishiya Karst Cave in Xiahe, China. The fossil was originally discovered in 1980 by a local monk who donated it to the 6th Gung-Thang Living Buddha who then passed it on to Lanzhou University. Since 2010, researchers Fahu Chen and Dongju Zhang from Lanzhou University have been studying the area of the discovery and the cave site from where the mandible originated. In 2016, they initiated a collaboration with the Department of Human Evolution at the MPI-EVA and have since been jointly analysing the fossil.

While the researchers could not find any traces of DNA preserved in this fossil, they managed to extract proteins from one of the molars, which they then analysed applying ancient protein analysis. "The ancient proteins in the mandible are highly degraded and clearly distinguishable from modern proteins that may contaminate a sample," says Frido Welker of the MPI-EVA and the University of Copenhagen. "Our protein analysis shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave."

Primitive shape and large molars

The researchers found the mandible to be well-preserved. Its robust primitive shape and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neandertals and specimens from the Denisova Cave. Attached to the mandible was a heavy carbonate crust, and by applying U-series dating to the crust the researchers found that the Xiahe mandible is at least 160,000 years old. Chuan-Chou Shen from the Department of Geosciences at National Taiwan University, who conducted the dating, says: "This minimum age equals that of the oldest specimens from the Denisova Cave".

"The Xiahe mandible likely represents the earliest hominin fossil on the Tibetan Plateau," says Fahu Chen, director of the Institute of Tibetan Research, CAS. These people had already adapted to living in this high-altitude low-oxygen environment long before Homo sapiens even arrived in the region. Previous genetic studies found present-day Himalayan populations to carry the EPAS1 allele in their genome, passed on to them by Denisovans, which helps them to adapt to their specific environment.

"Archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene and successfully adapted to high-altitude low-oxygen environments long before the regional arrival of modern Homo sapiens," says Dongju Zhang. According to Hublin, similarities with other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. "Our analyses pave the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia."

 

 

Press release from the Max Planck Institute for Evolutionary Anthropology / Max-Planck-Institut für evolutionäre Anthropologie in Leipzig 

Tibetan plateau first occupied by middle Pleistocene Denisovans

Baishiya Karst Cave
Fieldwork in the Baishiya Karst Cave and surrounding regions. Credit: ITP

The Tibetan Plateau, as Earth's "Third Pole," was reported to be first occupied by modern humans probably armed with blade technology as early as 40 ka BP. However, no earlier hominin groups had been found or reported on the Tibetan Plateau until a recent study was published by Chinese researchers.

A joint research team led by CHEN Fahu from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences and ZHANG Dongju from the Lanzhou University reported their studies on a human mandible found in Xiahe, on the Northeastern Tibetan Plateau. The findings were published in Nature.

The researchers found that the mandible came from an individual who belonged to a population closely related to the Denisovans first found in Siberia. This population occupied the Tibetan Plateau in the Middle Pleistocene and adapted to this low-oxygen environment long before the arrival of modern Homo sapiens in the region.

So far, Denisovans are only known from a small collection of fossil fragments from Denisova Cave in Siberia. Traces of Denisovan DNA are found in present-day Asian, Australian and Melanesian populations, suggesting that these ancient hominins may have once been widespread.

This study confirms for the first time that Denisovans not only lived in East Asia but also on the high-altitude Tibetan Plateau. It also indicates that the previously found possible introgression of Denisovan DNA (EPAS1) into modern Tibetans and Sherpas, who mainly live on the high-altitude Tibetan Plateau and surrounding regions today, is probably derived or inherited locally on Tibetan Plateau from Xiahe hominin represented by this Xiahe mandible.

The reported Xiahe mandible was found on the Tibetan Plateau in the Baishiya Karst Cave in Xiahe, China. Researchers managed to extract collagen from one of the molars, which they then analysed using ancient protein analysis. Ancient protein data showed that the Xiahe mandible belonged to a hominin population closely related to the Denisovans from Denisova Cave.

The robust primitive shape of the mandible and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neandertals and specimens from the Denisova Cave.

Attached to the mandible was a heavy carbonate crust. By applying U-series dating to the crust, the researchers found that the Xiahe mandible is at least 160,000 years old, representing a minimum age of human presence on the Tibetan Plateau.

The similarities between the Xiahe mandible and other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. The current study paves the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia.

 

Press release from the Chinese Academy of Sciences


Middle Pleistocene asian Hualongdong Hualong cave

Middle Pleistocene human skull reveals variation and continuity in early Asian humans

Middle Pleistocene human skull reveals variation and continuity in early Asian humans

Middle Pleistocene asian Hualongdong
The Hualongdong Middle Pleistocene human skull and the collapsed cave site, with the fossil-bearing breccia in beige aournd the limestone blocks. Credit: WU Xiujie and Erik Trinkaus

A team of scientists led by LIU Wu and WU Xiujie from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences reported the first ever Middle Pleistocene human skull found in southeastern China, revealing the variation and continuity in early Asian humans. Their findings were published on April 30 in Proceedings of the National Academy of Sciences (PNAS).

Excavations in Middle Pleistocene cave deposits in southeastern China yielded a largely complete skull that exhibits morphological similarities to other East Asian Middle and Late Pleistocene archaic human remains, but also foreshadows later modern human forms.

Fossil evidence for human evolution in East Asia during the Pleistocene is often fragmentary and scattered, which makes evaluating the pattern of archaic human evolution and modern human emergence in the region complicated.

Middle Pleistocene asian Hualongdong Hualong cave
The virtual reconstruction of the Hualongdong 6 human skull, with mirror-imaged portions in gray, plus two of the few stone tools from the site. Credit: WU Xiujie

WU Xiujie and his colleagues reported the recent discovery of most of a skull and associated remains dating to around 300,000 years ago in Hualong Cave (Hualongdong). The features of the Hualongdong fossils complement those of other East Asian remains in indicating a continuity of form through the Middle Pleistocene and into the Late Pleistocene.

In particular, the skull features a low and wide braincase with a projecting brow but a less prominent midface, as well as an incipient chin. The teeth are simple in form, contrasting with other archaic East Asian fossils, and its third molar is either reduced in size or absent.

According to the authors, the remains not only add to the expected variation of these Middle Pleistocene humans, recombining features present in other individuals from the same time period, but also foreshadow developments in modern humans, providing evidence for regional continuity.

 

Press release from the Chinese Academy of Sciences


Tongzi hominids China Late Middle Pleistocene

Tongzi hominids are potentially a new human ancestor in Asia

Tongzi hominids are potentially a new human ancestor in Asia

Tongzi hominids China Late Middle Pleistocene
Tongzi teeth. Credit: Song Xing

The CENIEH has been participating in a comparative research about human teeth discovered in this Southern China site which has revealed that Tongzi's teeth do not fit the morphological pattern of traditional Homo erectus.

The Researchers María Martinón-Torres and José María Bermúdez de Castro have co-authored a research about the hominids from Tongzi which was published in the Journal of Human Evolution from the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) which reveals that Tongzi teeth do not fit the morphological pattern of traditional Homo erectus and that these teeth could potentially represent the highly targeted "Denisovans".

Between 1972 and 1983, the four teeth were discovered in the Yanhui Cave in Tongzi, Southern China. Their chronology is between 172,000 and 240,000 years old and they were originally identified as late Homo erectus or ancient Homo sapiens.

This research was led by Song Xing from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing (IVVP). The morphology of hominid teeth has been reassessed by geometric morphometrical analysis and Micro-Computed Tomography (micro-CT) as well as through morphological standard comparisons.

Tongzi teeth have been primarily compared with hominids during the same chronological period (Late Middle Pleistocene) and/or in the same geographical region (East Asia). However, the comparative sample includes a wide range of hominids.

More generally, the results indicate the existence of more than one human population in East Asia during this period: one which may be taxonomically classified as Homo erectus (exemplified by fossils such as Zhoukoudian, Hexian and Yiyuan); and a second which may be characterized by the existence of derived traits more commonly observed in recent species of the Homo genus, such as crown symmetry, tongue thrusting and the simplified dentine surface of the third premolar.

"More genetic and fossil discoveries would be necessary to evaluate the taxonomy of the "non-erectus" populations of the Middle Pleistocene, such as the Tongzi hominids, which could be good candidates for the Denisovan ancestry," says María Martinón-Torres.

The Denisovans

These populations are related to the Neanderthals who lived in Asia during the Late Middle Pleistocene and the Upper Pleistocene period which was discovered in 2010 from the genetic analysis of a phalanx and a tooth found in the Denisova cave in the Altai massif (Russia). An abundant amount of genetic information has been collected from the Denisovans but there are very few fossil remains. Therefore, both their physical appearance and their identification in the fossil record remain a mystery.

 

Full bibliographic information

Xing, S., Martinón-Torres, M., & Bermúdez de Castro, J. M. (2019). Late Middle Pleistocene hominin teeth from Tongzi, southern China. Journal of Human Evolution, 130, 96-108. doi: 10.1016/j.jhevol.2019.03.001.

 

Press release from Centro Nacional de Investigación sobre la Evolución Humana CENIEH/ (ES)