"Dragon man"prompts rethinking of Middle Pleistocene hominin systematics in Asia

Dear Editor,Chibanian(Middle Pleistocene)hominin fossils that could not be easily assigned to Homo erectus,H.neanderthalensis,or H.sapiens have traditionally been as-signed to an alinclusive group:"archaic H.sapiens."In an insightful observation of the Chibanian record almost four decades ago however,Tattersall railed against the use of the word"archaic"in this sense when referring to the human fossil record,as he justifiably noted that no other biological organism has the word"archaic"attached to it'For example,no one refers to an earlier version of Canis domesticus as"archaic"C.domesticus.The ancestor of the domestic dog is,and always has been,considered to be C.lupus.In Tattersall's opinion,it would seem that these"archaic H.sapiens"fossils should be assigned to one or more formal taxonomic names.As such,terms such as"archaic H.sapiens,""mid-Pleistocene Homo,"and"Middle Pleistocene Homo"have al-ways been considered to be wastebasket taxa that include way too much morphological variabilty for one proposed taxonomic group.Continuing to use wastebasket taxa only hinders any attempts to understand true phylogenetic and evolutionary relationships.

Lufengpithecus inner ear provides evidence of a common locomotor repertoire ancestral to human bipedalism

Various lines of evidence have been used to infer the origin of human bipedalism,but the paucity of hominoid postcranial fossils and the diversity of inferred locomotor modes have tended to confound the reconstruction of ancestral morphotypes.Examination of the bony labyrinth morphology of the inner ear of extinct and living hominoids provides independent evidence for inferring the evolution of hominoid locomotor patterns.New computed tomography data and morphometric analyses of the Late Miocene ape Lufengpithecus indicate that it and other stem great apes possess labyrinths similar to one another and show that hominoids initially evolved from a positional repertoire that included orthogrady,below-branch forelimb suspension and progression,above-branch bipedalism,climbing,clambering,and leaping(hylobatid-like)to one that comprised above-branch quadrupedalism,below-branch forelimb suspension,vertical climbing,limited leaping,terrestrial quadrupedal running and walking,possibly with knuckle walking,and short bouts of bipedalism(chimpanzee-like).The bony labyrinth morphology of Lufengpithecus indicates that it probably conforms more closely to the last common ancestors of crown hominoids and hominids in its locomotor behavior than do other Miocene hominoids.Human bipedalism evolved from this common archetypal Lufengpithecus-like locomotor repertoire.The low evolutionary rate of semicircular canal morphology suggests that Lufengpithecus experienced a relative stasis in locomotor behavior,probably due to the uplift of the Tibetan Plateau,which created a stable environment in the Miocene of southwestern China.

Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage

It has recently become clear that several human lineages coexisted with Homo sapiens during the late Middle and Late Pleistocene.Here,we report an archaic human fossil that throws new light on debates concerning the diversification of the Homo genus and the origin of H.sapiens.The fossil was recovered in Harbin city in northeastern China,with a minimum uranium-series age of 146 ka.This cranium is one of the best preserved Middle Pleistocene human fossils.Its massive size,with a large cranial capacity(
1,420 mL)falling in the range of modern humans,is combined with a mosaic of primitive and derived characters.It differs from all the other named Homo species by presenting a combination of features,such as long and low cranial vault,a wide and low face,large and almost square orbits,gently curved but massively developed supraorbital torus,flat and low cheekbones with a shallow canine fossa,and a shallow palate with thick alveolar bone supporting very large molars.The excellent preservation of the Harbin cranium advances our understanding of several less-complete late Middle Pleistocene fossils from China,which have been interpreted as local evolutionary intermediates between the earlier species Homo erectus and later H.sapiens.Phylogenetic analyses based on parsimony criteria and Bayesian tip-dating suggest that the Harbin cranium and some other Middle Pleistocene human fossils from China,such as those from Dali and Xiahe,form a third East Asian lineage,which is a part of the sister group of the H.sapiens lineage.Our analyses of such morphologically distinctive archaic human lineages from Asia,Europe,and Africa suggest that the diversification of the Homo genus may have had a much deeper timescale than previously presumed.Sympatric isolation of small populations combined with stochastic long-distance dispersals is the best fitting biogeographical model for interpreting the evolution of the Homo genus.

Geochemical provenancing and direct dating of the Harbin archaic human cranium

As one of the most complete archaic human fossils,the Harbin cranium provides critical evidence for studying the diversification of the Homo genus and the origin of Homo sapiens.However,the unsystematic recovery of this cranium and a long and confused history since the discovery impede its accurate dating.Here,we carried out a series of geochemical analyses,including non-destructive X-ray fluorescence(XRF),rare earth elements(REE),and the Sr isotopes,to test the reported provenance of the Harbin cranium and get better stratigraphic constraints.The results show that the Harbin cranium has very similar XRF element distribution patterns,REE concentration patterns,and Sr isotopic compositions to those of the Middle Pleistocene-Holocene mammalian and human fossils recently recovered from the Harbin area.The sediments adhered in the nasal cavity of the Harbin cranium have a 87Sr/86Sr ratio of 0.711898,falling in the variation range measured in a core drilled near the Dongjiang Bridge,where the cranium was discovered during its reconstruction.The regional stratigraphic correlations indicate that the Harbin cranium was probably from the upper part of the Upper Huangshan Formation of the Harbin area,which has an optically stimulated luminescence dating constraint between 138 and 309 ka.U-series disequilibrium dating(n=10)directly on the cranium suggests that the cranium is older than 146 ka.The multiple lines of evidence from our experiments consistently support the theory that the Harbin cranium is from the late Middle Pleistocene of the Harbin area.Our study also shows that geochemical approaches can provide reliable evidence for locating and dating unsystematically recovered human fossils,and potentially can be applied to other human fossils without clear provenance and stratigraphy records.

Late Middle Pleistocene Harbin cranium represents a new Homo species

In eastern Asia,several Middle-Late Pleistocene human fossils,such as the Dali,Jinniushan,Hualongdong,and Harbin crania,evidently resemble each other and are phylogenetically closer to H.sapiens than to H.neanderthalensis or other archaic humans.1 The Harbin cranium is the best preserved of this group.It shows a mosaic combination of plesiomorphic and apomorphic features.Here,we suggest that the Harbin skull should be recognized as a new species of Homo.

Latest Middle Miocene fauna and flora from Kumkol Basin of northern Qinghai-Xizang Plateau and paleoenvironment

We report 7 mammalian and 16 pollen species from the top of the Shimagou Formation in Kumkol Basin of northern Qinghai-Xizang Plateau, whose age is latest Middle Miocene(about 12.5 Ma). We erect a new species of fossil rodent,Spermophilinus kumkolensis sp. nov. The micromammalian fauna from the Kumkol Basin shares high similarities with contemporary faunas from Europe and northern China, indicating the existence of active zoogeographic exchange between Europe and northern Asia. Trees are dominant in pollen fossils, and herbs and shrubs are minorities. Broadleaved Quercus and Fagus predominate in tree pollens. The flora reconstructed by pollens displays a mixture of evergreen broadleaved forest and dry and warm steppe landscape. Compared to the modern vegetation in Yunnan region, the latest Middle Miocene flora in the Kumkol Basin represents a distinct vertical distribution. The ecotypes of the latest Middle Miocene fauna and flora in the Kumkol Basin,as a whole, are markedly different from those of modern animals and vegetation, the past climate being more suitable than today.

Paleogene mammalian fauna exchanges and the paleogeographic pattern in Asia

Mammals are the most important elements in Cenozoic terrestrial ecosystem. The composition and the character of a mammalian fauna are controlled by evolution time and evolutionary rate. Here we took 50 Asian Paleogene mammalian faunas as representatives and applied Bayesian Tip-dating method to infer the relationships and divergence times among these faunas.Based on the results of Bayesian Tip-dating analyses, we discussed the correlation between the paleogeographic changes and the mammalian fauna turn-overs. Compared with the traditional fauna correlation and sorting, Bayesian Tip-dating analyses revealed more detailed similarities reflected via the divergence times among the 50 faunas. We discovered that the early Eocene mammalian fauna, which firstly appeared in India subcontinent, is similar to the faunas of the same age in other parts of Asia. It is likely that a passage for the mammalian dispersal was formed before early Eocene. Bayesian inferring suggests that the first appearance of the dispersal passage is during 64.8–61.3 Ma. This time window is close to the time estimation for the initial time of India-Asia collision. During 57.1–47.2 Ma, India subcontinent probably had a habitat different from the main part of Asia, as it was reflected from the composition of the mammalian faunas. It is probably correlated with the uplifted Gangdese Mountain and shallow seas and lowlands on both sides of the collision region. The very remote divergence time(64.8 Ma) estimated by Bayesian inferring reflects the mammalian fauna turnover during the Eocene-Oligocene transition, obviously affected by the global cooling. Till the end of Oligocene, the Arabic Peninsula and Asian mainland remained separated and the mammalian faunas did not show clear connection.