Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya

Sites in eastern Africa have shed light on the emergence and early evolution of the genus Homo. The best known early hominin species, H. habilis and H. erectus, have often been interpreted as time-successive segments of a single anagenetic evolutionary lineage. The case for this was strengthened by the discovery of small early Pleistocene hominin crania from Dmanisi in Georgia that apparently provide evidence of morphological continuity between the two taxa. Here we describe two new cranial fossils from the Koobi Fora Formation, east of Lake Turkana in Kenya, that have bearing on the relationship between species of early Homo. A partial maxilla assigned to H. habilis reliably demonstrates that this species survived until later than previously recognized, making an anagenetic relationship with H. erectus unlikely. The discovery of a particularly small calvaria of H. erectus indicates that this taxon overlapped in size with H. habilis, and may have shown marked sexual dimorphism. The new fossils confirm the distinctiveness of H. habilis and H. erectus, independently of overall cranial size, and suggest that these two early taxa were living broadly sympatrically in the same lake basin for almost half a million years.     

Early Pleistocene hominid teeth recovered in Mohui cave in Bubing Basin, Guangxi,South China

Since the 1950s, researchers who examine the issue of human beginnings often turn to Africa where there is a picture of human origins and evolution based on African hominid fossils with ages that are constantly revised to be older and older. However, there are many other unsolved problems about early human origins and evolution that may be solved by looking outside Africa. Over seventy years ago, Asia was described as a dispersal center of the earliest human industry, and a key arena for huma…     

A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia

Currently, it is widely accepted that only one hominin genus, Homo, was present in Pleistocene Asia, represented by two species, Homo erectus and Homo sapiens. Both species are characterized by greater brain size, increased body height and smaller teeth relative to Pliocene Australopithecus in Africa. Here we report the discovery, from the Late Pleistocene of Flores, Indonesia, of an adult hominin with stature and endocranial volume approximating 1 m and 380 cm3, respectively--equal to the smallest-known australopithecines. The combination of primitive and derived features assigns this hominin to a new species, Homo floresiensis. The most likely explanation for its existence on Flores is long-term isolation, with subsequent endemic dwarfing, of an ancestral H. erectus population. Importantly, H. floresiensis shows that the genus Homo is morphologically more varied and flexible in its adaptive responses than previously thought.     

Stratigraphic,chronological and behavioural contexts of Pleistocene Homo sapiens from Middle Awash,Ethiopia

Clarifying the geographic, environmental and behavioural contexts in which the emergence of anatomically modern Homo sapiens occurred has proved difficult, particularly because Africa lacked adequate geochronological, palaeontological and archaeological evidence. The discovery of anatomically modern Homo sapiens fossils at Herto, Ethiopia, changes this. Here we report on stratigraphically associated Late Middle Pleistocene artefacts and fossils from fluvial and lake margin sandstones of the Upper Herto Member of the Bouri Formation, Middle Awash, Afar Rift, Ethiopia. The fossils and artefacts are dated between 160,000 and 154,000 years ago by precise age determinations using the 40Ar/39Ar method. The archaeological assemblages contain elements of both Acheulean and Middle Stone Age technocomplexes. Associated faunal remains indicate repeated, systematic butchery of hippopotamus carcasses. Contemporary adult and juvenile Homo sapiens fossil crania manifest bone modifications indicative of deliberate mortuary practices.     

斑尾榛鸡南迁及其与花尾榛鸡分布区间断成因探讨

更新世中期斑尾榛鸡的原始种群因冰川作用及相近种花尾榛鸡种群的竞争排挤南廷到青藏高原东部、东南部山地。当时这些地区的森林和适度的冰雪环境适于其生活，定居下来，经久进化。自然力和人类开发作用使东北平原，华北、黄土高原的原始森林消失，再加入类狩猎活动，致使两种榛鸡分布区间断。     

Remains of Homo erectus from Bouri, Middle Awash, Ethiopia

The genesis, evolution and fate of Homo erectus have been explored palaeontologically since the taxon's recognition in the late nineteenth century. Current debate is focused on whether early representatives from Kenya and Georgia should be classified as a separate ancestral species ('H. ergaster'), and whether H. erectus was an exclusively Asian species lineage that went extinct. Lack of resolution of these issues has obscured the place of H. erectus in human evolution. A hominid calvaria and postcranial remains recently recovered from the Dakanihylo Member of the Bouri Formation, Middle Awash, Ethiopia, bear directly on these issues. These approximately 1.0-million-year (Myr)-old Pleistocene sediments contain abundant early Acheulean stone tools and a diverse vertebrate fauna that indicates a predominantly savannah environment. Here we report that the 'Daka' calvaria's metric and morphological attributes centre it firmly within H. erectus. Daka's resemblance to Asian counterparts indicates that the early African and Eurasian fossil hominids represent demes of a widespread palaeospecies. Daka's anatomical intermediacy between earlier and later African fossils provides evidence of evolutionary change. Its temporal and geographic position indicates that African H. erectus was the ancestor of Homo sapiens.     

Postcranial evidence from early Homo from Dmanisi, Georgia

The Plio-Pleistocene site of Dmanisi, Georgia, has yielded a rich fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although the craniomandibular morphology of early Homo is well known as a result of finds from Dmanisi and African localities, data about its postcranial morphology are still relatively scarce. Here we describe newly excavated postcranial material from Dmanisi comprising a partial skeleton of an adolescent individual, associated with skull D2700/D2735, and the remains from three adult individuals. This material shows that the postcranial anatomy of the Dmanisi hominins has a surprising mosaic of primitive and derived features. The primitive features include a small body size, a low encephalization quotient and absence of humeral torsion; the derived features include modern-human-like body proportions and lower limb morphology indicative of the capability for long-distance travel. Thus, the earliest known hominins to have lived outside of Africa in the temperate zones of Eurasia did not yet display the full set of derived skeletal features.     

2017年古生物学热点回眸

 2017年国际古生物研究取得了一系列重要进展。本文介绍地球早期生命研究、最古老树木生长模式、生物宏演化、琥珀中的特异保存化石、三维翼龙胚胎、最早的智人等具体成果，希望由此反映国际古生物研究领域的前沿热点及中国古生物学界所做的突出贡献。     

Rapid body size decline in Alaskan Pleistocene horses before extinction

About 70% of North American large mammal species were lost at the end of the Pleistocene epoch. The causes of this extinction--the role of humans versus that of climate--have been the focus of much controversy. Horses have figured centrally in that debate, because equid species dominated North American late Pleistocene faunas in terms of abundance, geographical distribution, and species variety, yet none survived into the Holocene epoch. The timing of these equid regional extinctions and accompanying evolutionary changes are poorly known. In an attempt to document better the decline and demise of two Alaskan Pleistocene equids, I selected a large number of fossils from the latest Pleistocene for radiocarbon dating. Here I show that horses underwent a rapid decline in body size before extinction, and I propose that the size decline and subsequent regional extinction at 12,500 radiocarbon years before present are best attributed to a coincident climatic/vegetational shift. The present data do not support human overkill and several other proposed extinction causes, and also show that large mammal species responded somewhat individualistically to climate changes at the end of the Pleistocene.     

河南灵井许昌人遗址古人类化石及相关研究进展

 2007年和2014年，河南灵井遗址出土的距今10万年左右的许昌人头骨化石引起古人类学界的广泛关注，研究显示晚更新世早期中国境内可能并存多种古人类成员，不同群体之间有杂交或者基因交流产生。许昌人为中国古人类演化的地区连续性以及与欧洲古人类之间的交流提供了一定程度的支持。本文回顾了许昌人化石的发现历史、复原和研究过程，介绍了许昌人伴生的哺乳动物化石、石制品、骨质工具的最新研究进展；讨论了灵井遗址未来工作前景。许昌人化石及伴生的文化遗物为探讨当时人类的体质特征、行为方式及中国古人类的演化模式提供了重要的参考资料。     

The brain morphology of Homo Liujiang cranium fossil by three-dimensional computed tomography

The Liujiang cranium is the most complete and well-preserved late Pleistocene human fossils ever unearthed in south China. Because the endocranial cavity is filled with hard stone matrix, earlier studies focused only on the exterior morphology of the specimen using the traditional methods. In order to derive more information for the phyletic evaluation of the Liujiang cranium, high-resolution industrial computed tomography （CT） was used to scan the fossil, and the three-dimensional （3D） brain image was reconstructed. Compared with the endocasts of the hominin fossils （Hexian, Zhoukoudian, KNM-WT 15000, Sm 3, Kabwe, Brunn 3, Predmost） and modern Chinese, most morphological features of the Liujiang brain are in common with modern humans, including a round brain shape, bulged and wide frontal lobes, an enlarged brain height, a full orbital margin and long parietal lobes. A few differences exist between Liujiang and the modern Chinese in our sample, including a strong posterior projection of the occipital lobes, and a reduced cerebellar lobe. The measurement of the virtual endocast shows that the endocranial capacity of Liujiang is 1567 cc, which is in the range of Late Homo sapiens and much beyond the mean of modern humans. The brain morphology of Liujiang is assigned to Late Homo sapiens.     

Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins.

A modern human-like sequence of dental development, as a proxy for the pace of life history, is regarded as one of the diagnostic hallmarks of our own genus Homo. Brain size, age at first reproduction, lifespan and other life-history traits correlate tightly with dental development. Here we report differences in enamel growth that show the earliest fossils attributed to Homo do not resemble modern humans in their development. We used daily incremental markings in enamel to calculate rates of enamel formation in 13 fossil hominins and identified differences in this key determinant of tooth formation time. Neither australopiths nor fossils currently attributed to early Homo shared the slow trajectory of enamel growth typical of modern humans; rather, both resembled modern and fossil African apes. We then reconstructed tooth formation times in australopiths, in the approximately 1.5-Myr-old Homo erectus skeleton from Nariokotome, Kenya, and in another Homo erectus specimen, Sangiran S7-37 from Java. These times were shorter than those in modern humans. It therefore seems likely that truly modern dental development emerged relatively late in human evolution.     

Pleistocene Homo sapiens from Middle Awash,Ethiopia

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto, Middle Awash, Ethiopia, that fill this gap and provide crucial evidence on the location, timing and contextual circumstances of the emergence of Homo sapiens. Radioisotopically dated to between 160,000 and 154,000 years ago, these new fossils predate classic Neanderthals and lack their derived features. The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa.     

The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age

One of the most hotly debated and frontal issues in paleoanthropology focuses on the origins of modern humans. Recently, an incomplete hominin mandible with a distinctly weaker mental protuberance than modern human and a great variety of coexisting fossil mammals were unearthed from the Homo sapiens Cave of Mulan Mountain, Chongzuo, Guangxi. The mammalian fauna from the Homo sapiens Cave characterized by the combination of Elephas kiangnanensis, first occurring Elephas maixmus, and Megatapirus augustus, and strikingly different from the Early Pleistocene Gigantopithecus fauna and the Middle Pleistocene Ailuropoda-Stogodon fauna of South China could be regarded as an early representive of the typical Asian elephant fauna. Faunal analysis, biostratigraphic correlation, and, most importantly, U-series dating all consistently support an estimate of ca. 110 ka for the age of the fossil Homo sapiens and coexisting mammalian fauna, that is, the early Late Pleistocene. The fauna is mainly made up of tropical-subtropical elements, but grassland elements have a much greater variety than forest elements, which probably indicates a drier climate at that time. This discovery of early Homo sapiens at the Mulan Mountain will play a significant role in the study of the origin and its environmental background of modern humans.     

On fossil remains of Early Pleistocene tapir (Perissodactyla, Mammalia) from Fanchang, Anhui

The materials of Tapirus from Renzidong,Fanchang, Anhui Province, are the best ones among the early most Pleistocene findings in China up to now, not only in richness, but also in completeness. The fossils contain complete tooth rows of both the upper and the lower, as well as most parts of the postcranial skeletons. These materials are very helpful in understanding the evolutionary level of this kind of animal. In morphology, the materials from Fanchang appear to be very similar to Tapirus sanyuanensis, and can be placed within this species. The materials from Fanchang provided sound evidence to distinguish the Early Pleistocene tapirs and the living form Tapirus indicus. As to the geological distribution, it can be tentatively concluded that Tapirus sanyuanensis and Tapirus sinensis only appeared in Early Pleistocene, Megatapirus appeared after Early Pleistocene,and lasted until Holocene. The Early Pleistocene tapirs of South China resemble Megatapirus more closely than Tapirus indicus.     

First discovery of fossil Diplothrix (Muridae, Rodentia) outside the Ryukyu Islands, Japan

The first Diplothrix (Muridae, Rodentia) fossils of the early Early Pleistocene are described as D. yangziensis sp. nov., which were collected from the Renzidong Cave deposits in Anhui Province, Eastern China. Diplothrix was previously represented by a single species, D. legata, whose geographical distribution during the Late Pleistocene is restricted to the Ryukyu Islands, Japan. With straight chevrons on M1, distinct t3 and t9 on upper molars, primitive M3, mlc on m1, and developed a-lab on m2 and m3, the new species is morphologically distinct from other large murids in East Asia, and should belong to the genus Diplothrix. There are also differences in molar morphology between the new species and D. legata, the type species of Diplothrix, as well as other known fossils. For example, D. yangziensis sp. nov. has a smaller size, a more elongated crown, developed precingulum and pc on M1, more primitive M3, weaker mlc and more primitive pc on m1, and stronger plc and pc on m3. In short, Diplothrix yangziensis sp. nov. is evidently more primitive than D. legata, suggesting that the former is likely the ancestor of the latter. Diplothrix yangziensis sp. nov. is the first discovery of the genus outside the Ryukyu Islands, Japan and is also the earliest and most primitive species of the genus in Eurasia. Its discovery has significant implications for reconstructing the evolution and dispersal pattern of Diplothrix, as well as for discussing its palaeoecological variation.     

An Asian perspective on early human dispersal from Africa

The past decade has seen the Pliocene and Pleistocene fossil hominin record enriched by the addition of at least ten new taxa, including the Early Pleistocene, small-brained hominins from Dmanisi, Georgia, and the diminutive Late Pleistocene Homo floresiensis from Flores, Indonesia. At the same time, Asia's earliest hominin presence has been extended up to 1.8 Myr ago, hundreds of thousands of years earlier than previously envisaged. Nevertheless, the preferred explanation for the first appearance of hominins outside Africa has remained virtually unchanged. We show here that it is time to develop alternatives to one of palaeoanthropology's most basic paradigms: 'Out of Africa 1'.     

Evidence that humans evolved from a knuckle-walking ancestor

Bipedalism has traditionally been regarded as the fundamental adaptation that sets hominids apart from other primates. Fossil evidence demonstrates that by 4.1 million years ago, and perhaps earlier, hominids exhibited adaptations to bipedal walking. At present, however, the fossil record offers little information about the origin of bipedalism, and despite nearly a century of research on existing fossils and comparative anatomy, there is still no consensus concerning the mode of locomotion that preceded bipedalism. Here we present evidence that fossils attributed to Australopithecus anamensis (KNM-ER 20419) and A. afarensis (AL 288-1) retain specialized wrist morphology associated with knuckle-walking. This distal radial morphology differs from that of later hominids and non-knuckle-walking anthropoid primates, suggesting that knuckle-walking is a derived feature of the African ape and human clade. This removes key morphological evidence for a Pan-Gorilla clade, and suggests that bipedal hominids evolved from a knuckle-walking ancestor that was already partly terrestrial.     

A new hominin foot from Ethiopia shows multiple Pliocene bipedal adaptations

A newly discovered partial hominin foot skeleton from eastern Africa indicates the presence of more than one hominin locomotor adaptation at the beginning of the Late Pliocene epoch. Here we show that new pedal elements, dated to about 3.4 million years ago, belong to a species that does not match the contemporaneous Australopithecus afarensis in its morphology and inferred locomotor adaptations, but instead are more similar to the earlier Ardipithecus ramidus in possessing an opposable great toe. This not only indicates the presence of more than one hominin species at the beginning of the Late Pliocene of eastern Africa, but also indicates the persistence of a species with Ar. ramidus-like locomotor adaptation into the Late Pliocene.     

Archaeology and age of a new hominin from Flores in eastern Indonesia

Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominins, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis. The finds comprise the cranial and some post-cranial remains of one individual, as well as a premolar from another individual in older deposits. Here we describe their context, implications and the remaining archaeological uncertainties. Dating by radiocarbon (14C), luminescence, uranium-series and electron spin resonance (ESR) methods indicates that H. floresiensis existed from before 38,000 years ago (kyr) until at least 18 kyr. Associated deposits contain stone artefacts and animal remains, including Komodo dragon and an endemic, dwarfed species of Stegodon. H. floresiensis originated from an early dispersal of Homo erectus (including specimens referred to as Homo ergaster and Homo georgicus) that reached Flores, and then survived on this island refuge until relatively recently. It overlapped significantly in time with Homo sapiens in the region, but we do not know if or how the two species interacted.