New Miocene locality in Turkey with evidence on the origin of Ramapithecus and Sivapithecus.

Collections in early Middle Miocene deposits at Pasalar in Turkey have yielded a very rich fauna. Included in this are two hominoid species referred here to Sivapithecus darwini (Abel) 1902 and Ramapithecus wickeri (Leakey) 1962. These are both more primitive morphologically and earlier in time than other species of these genera, and they provide evdence that Sivapithecus and Ramapithecus are closely related and that their early diversification may have occurred not in Africa but in Eurasia.     

A new orang-utan relative from the Late Miocene of Thailand

The fossil record of the living great apes is poor. New fossils from undocumented areas, particularly the equatorial forested habitats of extant hominoids, are therefore crucial for understanding their origins and evolution. Two main competing hypotheses have been proposed for orang-utan origins: dental similarities support an origin from Lufengpithecus, a South Chinese and Thai Middle Miocene hominoid; facial and palatal similarities support an origin from Sivapithecus, a Miocene hominoid from the Siwaliks of Indo-Pakistan. However, materials other than teeth and faces do not support these hypotheses. Here we describe the lower jaw of a new hominoid from the Late Miocene of Thailand, Khoratpithecus piriyai gen. et sp. nov., which shares unique derived characters with orang-utans and supports a hypothesis of closer relationships with orang-utans than other known Miocene hominoids. It can therefore be considered as the closest known relative of orang-utans. Ancestors of this great ape were therefore evolving in Thailand under tropical conditions similar to those of today, in contrast with Southern China and Pakistan, where temperate or more seasonal climates appeared during the Late Miocene.     

Significance of enamel thickness in hominoid evolution

Enamel thickness has assumed unique importance in the debate about the hominid status of Ramapithecus, despite the fact that there is little agreement about the meaning of 'thick enamel' or the significance of enamel thickness for hominoid taxonomy. My aim here is to evaluate the usefulness of enamel thickness and microstructure as characteristics for determining the relationships of the later Miocene hominoids, based both on a quantitative study of enamel thickness in extant hominoids and four species of later Miocene Sivapithecus (including 'Ramapithecus') and on scanning electron microscope analysis of enamel microstructure. Four categories of enamel thickness are defined metrically here and have been related to enamel microstructure and developmental rates. Thin fast-formed (pattern 3) enamel represents the ancestral condition in hominoids; it increased developmentally to thick pattern 3 enamel in the great ape and human clade and that condition is primitively retained in Homo and in the fossil hominoid Sivapithecus (including 'Ramapithecus'). Enamel thickness has been secondarily reduced in the African apes and also, although at a different rate and extent, in the orang-utan. Thick enamel, previously the most important characteristic in arguments about the earliest hominid, does not therefore identify a hominid.     

New hominid skull material from the late Miocene of Macedonia in northern Greece

Miocene hominoid material is very scarce and has previously only been reported as cranial fragments in the Old World. Here we describe a new specimen of Ouranopithecus macedoniensis, which consists of the right part of the face of an adult male with a portion of the frontal bone, a portion of the left part of the face and the maxilla with complete dentition except the right third molar. The characters of this specimen are not congruent with those of Sivapithecus and the pongids, but are more primitive and plesiomorphic for the recent hominid clade (Gorilla, Pan and Homo). The dental characters differ morphologically and metrically from those of the recent great apes and fit better with Australopithecus afarensis. Ouranopithecus now seems the best candidate forerunner of the Plio-pleistocene Homininae (Australopithecus and Homo). This specimen was discovered in September 1989, in the late Miocene deposits of central Macedonia (G.K., L. de B. and G.B.), and prepared by G.K. in Thessaloniki and G. Mouchelin in Poitiers. It comes from the new locality of Xirochori in the red sandstone of the Nea Messimbria formation. The fossil is the property of the University of Thessaloniki, Greece (catalogue number XIR-1).     

New Sivapithecus humeri from Pakistan and the relationship of Sivapithecus and Pongo

New humeri of two species of the Miocene hominoid Sivapithecus are described from near Chinji in Pakistan from between approximately 9 and 11 Myr ago. Sivapithecus, a middle and late Miocene hominoid from Turkey and Indo-Pakistan, is overall unlike any living hominoid, although facial-palatal similarities to the extant orangoutan, Pongo, have been used to support a hypothesis of close relationship. Living hominoids have postcranial similarities assumed to be shared derived, among them features of the proximal humerus. However, the new Sivapithecus proximal humeri differ from those of living hominoids, supporting an alternative hypothesis in which Sivapithecus and Pongo are not closely related. It is not clear how to choose between these incompatible hypotheses.     

A Middle Miocene hominoid from Thailand and orangutan origins

The origin of orangutans has long been debated. Sivapithecus is considered to be the closest ancestor of orangutans because of its facial-palatal similarities, but its dental characteristics and postcranial skeleton do not confirm this phylogenetic position. Here we report a new Middle Miocene hominoid, cf. Lufengpithecus chiangmuanensis n. sp. from northern Thailand. Its dental morphology relates it to the Pongo clade, which includes Lufengpithecus, Sivapithecus, Gigantopithecus, Ankarapithecus and possibly Griphopithecus. Our new species displays striking dental resemblances with living orangutans and appears as a more likely candidate to represent an ancestor of this ape. In addition, it originates from the geographic area of Pleistocene orangutans. But surprisingly, the associated flora shows strong African affinities, demonstrating the existence of a temporary floral and faunal dispersal corridor between southeast Asia and Africa during the Middle Miocene, which may have played a critical role in hominoid dispersion.     

A new hominid from the Upper Miocene of Chad,Central Africa

The search for the earliest fossil evidence of the human lineage has been concentrated in East Africa. Here we report the discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley. The fossils include a nearly complete cranium and fragmentary lower jaws. The associated fauna suggest the fossils are between 6 and 7 million years old. The fossils display a unique mosaic of primitive and derived characters, and constitute a new genus and species of hominid. The distance from the Rift Valley, and the great antiquity of the fossils, suggest that the earliest members of the hominid clade were more widely distributed than has been thought, and that the divergence between the human and chimpanzee lineages was earlier than indicated by most molecular studies.     

A complete human pelvis from the Middle Pleistocene of Spain.

The Middle Pleistocene site of Sima de los Huesos in Sierra de Atapuerca, Spain, has yielded around 2,500 fossils from at least 33 different hominid individuals. These have been dated at more than 200,000 years ago and have been classified as ancestors of Neanderthals. An almost complete human male pelvis (labelled Pelvis 1) has been found, which we associate with two fragmentary femora. Pelvis 1 is robust and very broad with a very long superior pubic ramus, marked iliac flare, and a long femoral neck. This pattern is probably the primitive condition from which modern humans departed. A modern human newborn would pass through the birth canal of Pelvis 1 and this would be even larger in a female individual. We estimate the body mass of this individual at 95 kg or more. Using the cranial capacities of three specimens from Sima de los Huesos, the encephalization quotients are substantially smaller than in Neanderthals and modern humans.     

非交换子群的共轭类为3的有限群

非交换子群的共轭类数对有限群结构有着重要的影响,关于此方面的研究已取的一定的研究成果.设G为有限群,用τ(G)表示群G中非交换子群的共轭类数.在以前的基础上,主要研究满足条件τ(G)=3的有限群的结构性质.用群论研究的方法和技巧,得到了这类群的同构分类,获得了一些比较有意义的结果.     

甘肃临夏盆地中新世地层及哺乳动物化石

甘肃临夏地区中新世哺乳动物化石引起学术界的重视。经过考察、发掘,哪现了大量的化石标本。由于发表的文章多为单篇,较分散,笔者收集整理,对材料进行了研究,认为甘肃临夏地区在近直余年来是全国发现中新世材料最多的地区,且有极高的研究价值,填补了我国中新世哺乳动物化石中的部分空白。     

湘西凤凰大马地区中、晚寒武世三叶虫

我国湘西大马-亥冲口-峨梨塘地区有大量三叶虫化石产出，它是我国南方已知含丰富化石产地之一．此地同样也是我国寒武系地层出露最完整的地区之一．特别是黔东和湘西交界处，寒武系岩石出露相当好，未变形，易辩认．部分产自亥冲口剖面的多节类三叶虫由现作者近年出版在别处，本文重点介绍几个近年新发现产自大马剖面的三叶虫．     

极小子群与有限群的结构研究

首先利用极小子群的中心化子和正规化子对若干有限群的结构进行了刻画，其次给出了非平凡交换子群个数≤4的有限群的完全分类．     

Juvenile hominoid cranium from the terminal Miocene of Yunnan, China

Fossil apes are known from several late Miocene localities in Yunnan Province, southwestern China, principally from Shihuiba (Lufeng) and the Yuanmou Basin, and represent three species of Lufengpithecus. They mostly comprise large samples of isolated teeth, but there are also several partial or complete adult crania from Shihuiba and a single juvenile cranium from Yuanmou. Here we describe a new, relatively complete and largely undistorted juvenile cranium from the terminal Miocene locality of Shuitangba, also in Yunnan. It is only the second ape juvenile cranium recovered from the Miocene of Eurasia and it is provisionally assigned to the species present at Shihuiba, Lufengpithecus lufengensis. Lufengpithecus has most often been linked to the extant orangutan, Pongo pygmaeus, but recent studies of the crania from Shihuiba and Yuanmou have demonstrated that this is unlikely. The new cranium reinforces the view that Lufengpithecus represents a distinct, late surviving lineage of large apes in the late Miocene of East Asia that does not appear to be closely affiliated with any extant ape lineage. It substantially increases knowledge of cranial morphology in Lufengpithecus and demonstrates that species of this genus represent a morphologically diverse radiation of apes, which is consistent with the dynamic tectonic and biotic milieu of southwestern China in the late Miocene.     

Vermicular fossils in the Early Cambrian Xidashan Formation in the Quruqtagh region of Xinjiang, China

Large amounts of vermicular fossils and a minor amount of sponge animal fossils have been found in the Early Cambrian Xidashan Formation in the region of Quruqtagh, Xinjiang. Vermicular fossils are generally more than 50 mm long and 0.3?1.4 mm wide; their wrinkled lamellae are microfine with 3?10 pieces within the length of every each millimeter. The fossils are considered to be Sabellidites cambriensis Sokolov (1965). The Xidashan Formation is the highest stratum in which Sabellidites occur, as has been so far reported.     

An exceptionally preserved vermiform mollusc from the Silurian of England

Studies of the origin and radiation of the molluscs have yet to resolve many issues regarding their nearest relatives, phylogeny and ancestral characters. The Polyplacophora (chitons) and the Aplacophora are widely interpreted as the most primitive extant molluscs, but Lower Palaeozoic fossils of the former lack soft parts, and the latter were hitherto unrecognized as fossils. The Herefordshire Lagerst?tte is a Silurian (about 425 Myr bp) deposit that preserves a marine biota in remarkable three-dimensional detail. The external surface of even non-biomineralized cuticle was preserved by entombment in volcanic ash, subsequent incorporation into concretions, and infilling of the fossils with sparry calcite. Here we describe, from this deposit, a complete vermiform mollusc, which we interpret as a plated aplacophoran. Serial grinding at intervals of tens of micrometres, combined with computer-based reconstruction methods, renders the fossils in the round.     

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.     

哈密翼龙及其3D胚胎化石研究

 翼龙是地球上第一类飞向天空也是唯一绝灭的飞行脊椎动物，人类对其产卵繁殖、生长发育和生活习性等方面的了解还十分有限。本文介绍了一件超过200枚哈密翼龙蛋、胚胎和骨骼化石三位一体保存的重要标本，包括16枚翼龙蛋含有三维立体的胚胎化石。针对这件全世界首次发现的3D翼龙胚胎，研究提出哈密翼龙具有相对早熟的胚胎发育模式，其后肢发育速度较前肢快，孵化之后只能走不能飞；胚胎发育期间牙齿尚未萌出，出生后还需要父母照料；从胚胎到亚成年都具有快速生长的骨骼结构；显示哈密翼龙具有群居的生活习性，白垩纪的湖泊风暴导致其集群死亡并快速埋藏。     

Periodicity of Retzius lines in fossil <Emphasis Type="Italic">Pongo</Emphasis> from South China

Periodicity of Retzius lines is a key factor in dental development. In this study, we examined the periodicity of Retzius lines in fossil Pongo from South China using polarized light microscope observation of dental ground sections. The periodicities all of the 15 teeth were 9 d. Comparisons of periodicity were made with extant primates, fossil apes and hominins. Periodicity of fossil Pongo from South China was relatively long but fell within the variation of extant Pongo, Gorilla and modern human, and longer than periodicity of Pan and other extant primates. Fossil Pongo from South China was similar to Lufengpithecus and Sivapithecus, shorter than Gigantopithecus and longer than European and African fossil apes and most early hominins in periodicity. Generally, the periodicities of Asian large-body fossil apes were longer than the periodicities of European and African large-body fossil apes in Miocene. Difference among species and trend of evolution in periodicity were analyzed and discussed. We found that periodicity might gradually increase from Proconsul in early Miocene to several fossil apes in Miocene and then Gigantopithecus in Pleistocene. In addition, this study made correlate analysis between periodicity and body mass respectively in males and females of six extant apes and five fossil apes, and found that periodicity positively correlated with body mass.     

A palaeontological solution to the arthropod head problem

The composition of the arthropod head has been one of the most controversial topics in zoology, with a large number of theories being proposed to account for it over the last century. Although fossils have been recognized as being of potential importance in resolving the issue, a lack of consensus over their systematics has obscured their contribution. Here, I show that a group of previously problematic Cambrian arthropods from the Burgess Shale and Chengjiang faunas form a clade close to crown-group euarthropods, the group containing myriapods, chelicerates, insects and crustaceans. They are characterized by modified or even absent endopods, and two pre-oral appendages. Comparison with reconstructions of the crown-group euarthropod ground plan and recent investigations into onychophorans demonstrates that these two appendages are the first antenna (of extant crustaceans) and a more anterior appendage associated with an ocular segment. The latter appendage has been reduced in all crown-group euarthropods. Its most likely relic is as a component of the labrum. These fossils thus tie together results from disparate living groups (onychophorans and euarthropods).     

Asa Issie, Aramis and the origin of Australopithecus

The origin of Australopithecus, the genus widely interpreted as ancestral to Homo, is a central problem in human evolutionary studies. Australopithecus species differ markedly from extant African apes and candidate ancestral hominids such as Ardipithecus, Orrorin and Sahelanthropus. The earliest described Australopithecus species is Au. anamensis, the probable chronospecies ancestor of Au. afarensis. Here we describe newly discovered fossils from the Middle Awash study area that extend the known Au. anamensis range into northeastern Ethiopia. The new fossils are from chronometrically controlled stratigraphic sequences and date to about 4.1-4.2 million years ago. They include diagnostic craniodental remains, the largest hominid canine yet recovered, and the earliest Australopithecus femur. These new fossils are sampled from a woodland context. Temporal and anatomical intermediacy between Ar. ramidus and Au. afarensis suggest a relatively rapid shift from Ardipithecus to Australopithecus in this region of Africa, involving either replacement or accelerated phyletic evolution.