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1.
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.  相似文献   

2.
D Pilbeam  M D Rose  J C Barry  S M Shah 《Nature》1990,348(6298):237-239
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.  相似文献   

3.
Extreme sexual dimorphism in a Miocene hominoid   总被引:2,自引:0,他引:2  
J Kelley  Q H Xu 《Nature》1991,352(6331):151-153
Some Miocene hominoids may have been extremely sexually dimorphic for body size, inferred from the apparent dimorphism of dental and gnathic remains. But this has never been demonstrated convincingly for any fossil species because of small sample sizes, uncertainties about the number of species in most fossil samples, and the inability to reliably sex individual specimens. Here we demonstrate a case of extreme dental dimorphism, and presumed body-size dimorphism, in a Miocene hominoid sample in which these limitations have been overcome. Lufengpithecus lufengensis from the late Miocene site of Lufeng, China, was more dimorphic than the most dimorphic living hominoid, the orangutan, and may have been more dimorphic than any living anthropoid.  相似文献   

4.
P Andrews  H Tobien 《Nature》1977,268(5622):699-701
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.  相似文献   

5.
Late Miocene hominids from the Middle Awash, Ethiopia.   总被引:8,自引:0,他引:8  
Y Haile-Selassie 《Nature》2001,412(6843):178-181
Molecular studies suggest that the lineages leading to humans and chimpanzees diverged approximately 6.5-5.5 million years (Myr) ago, in the Late Miocene. Hominid fossils from this interval, however, are fragmentary and of uncertain phylogenetic status, age, or both. Here I report new hominid specimens from the Middle Awash area of Ethiopia that date to 5.2-5.8 Myr and are associated with a wooded palaeoenvironment. These Late Miocene fossils are assigned to the hominid genus Ardipithecus and represent the earliest definitive evidence of the hominid clade. Derived dental characters are shared exclusively with all younger hominids. This indicates that the fossils probably represent a hominid taxon that postdated the divergence of lineages leading to modern chimpanzees and humans. However, the persistence of primitive dental and postcranial characters in these new fossils indicates that Ardipithecus was phylogenetically close to the common ancestor of chimpanzees and humans. These new findings raise additional questions about the claimed hominid status of Orrorin tugenensis, recently described from Kenya and dated to approximately 6 Myr.  相似文献   

6.
When, where and from which hominoid the human originated has been one of the key subjects in the study of human natural history. It is therefore very important to learn the chronological, geographical and taxonomic distribution of all hominoids. Yunnan Pr…  相似文献   

7.
Ramapithecines from China: evidence from tooth dimensions   总被引:1,自引:0,他引:1  
R K Wu  C E Oxnard 《Nature》1983,306(5940):258-260
Data obtained from ramapithecine specimens found in Asia, Africa and Europe have suggested the existence of two major subgroups, Ramapithecus and Sivapithecus, with Ramapithecus having pre-human status. Recently, however, it has been proposed that the fossils all belong to a single group, Sivapithecus, which is more closely related to the apes, in particular the orang-utan. Here we analyse data from a series of similar fossils which have been found in late Miocene coalfields in Lufeng, Yunnan Province, China. These include a number of almost complete jaws and five partial skulls which are more complete than any others so far known. A statistical analysis of the overall dimensions of the large number of teeth included in these finds shows that the differences between the groups previously assigned to Ramapithecus and Sivapithecus are greater than those found between the sexes in the most sexually dimorphic of the living great apes. Within the groups the distribution is bimodal and we suggest each group contains sex subgroups.  相似文献   

8.
L de Bonis  G Bouvrain  D Geraads  G Koufos 《Nature》1990,345(6277):712-714
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).  相似文献   

9.
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.  相似文献   

10.
Significance of enamel thickness in hominoid evolution   总被引:6,自引:0,他引:6  
L Martin 《Nature》1985,314(6008):260-263
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.  相似文献   

11.
Discoveries in Chad by the Mission Paleoanthropologique Franco-Tchadienne have substantially changed our understanding of early human evolution in Africa. In particular, the TM 266 locality in the Toros-Menalla fossiliferous area yielded a nearly complete cranium (TM 266-01-60-1), a mandible, and several isolated teeth assigned to Sahelanthropus tchadensis and biochronologically dated to the late Miocene epoch (about 7 million years ago). Despite the relative completeness of the TM 266 cranium, there has been some controversy about its morphology and its status in the hominid clade. Here we describe new dental and mandibular specimens from three Toros-Menalla (Chad) fossiliferous localities (TM 247, TM 266 and TM 292) of the same age. This new material, including a lower canine consistent with a non-honing C/P3 complex, post-canine teeth with primitive root morphology and intermediate radial enamel thickness, is attributed to S. tchadensis. It expands the hypodigm of the species and provides additional anatomical characters that confirm the morphological differences between S. tchadensis and African apes. S. tchadensis presents several key derived features consistent with its position in the hominid clade close to the last common ancestor of chimpanzees and humans.  相似文献   

12.
Lieberman E  Michel JB  Jackson J  Tang T  Nowak MA 《Nature》2007,449(7163):713-716
Human language is based on grammatical rules. Cultural evolution allows these rules to change over time. Rules compete with each other: as new rules rise to prominence, old ones die away. To quantify the dynamics of language evolution, we studied the regularization of English verbs over the past 1,200 years. Although an elaborate system of productive conjugations existed in English's proto-Germanic ancestor, Modern English uses the dental suffix, '-ed', to signify past tense. Here we describe the emergence of this linguistic rule amidst the evolutionary decay of its exceptions, known to us as irregular verbs. We have generated a data set of verbs whose conjugations have been evolving for more than a millennium, tracking inflectional changes to 177 Old-English irregular verbs. Of these irregular verbs, 145 remained irregular in Middle English and 98 are still irregular today. We study how the rate of regularization depends on the frequency of word usage. The half-life of an irregular verb scales as the square root of its usage frequency: a verb that is 100 times less frequent regularizes 10 times as fast. Our study provides a quantitative analysis of the regularization process by which ancestral forms gradually yield to an emerging linguistic rule.  相似文献   

13.
 南海碳酸盐台地分布自早中新世开始发育,至中中新世达到鼎盛,再到晚中新世大量台地被淹没而逐渐消亡。从分布看,南海碳酸盐台地具有南早北晚、东早西晚的发育规律;从堆积速率看,中中新统速率最大。控制这些台地的诞生、发育演化和消亡的因素十分复杂,可能包括构造活动、相对海平面的变化、陆源碎屑物质输入变化、古海洋环境变化。  相似文献   

14.
阿尔金山北麓晚新生代沉积物磁组构特征及其地质意义   总被引:1,自引:0,他引:1  
阿尔金山北麓晚新生代沉积物比较敏感地记录了阿尔金山构造活动的历史.通过对若羌米兰河口剖面晚新生代沉积物沉积学和磁组构特征分析,发现中新世晚期以来该区地层沉积变化明显,岩石磁化率椭球体以压扁为主,磁面理发育,磁化率椭球体最小轴方向为NNE-SSW和NNW-SSE,推测阿尔金山晚新生代以来可能至少经历了中新世末-上新世初、晚上新世和中更新世三次重大构造活动历史.根据磁化率各向异性最小轴方向的变化,结合地层不整合关系、沉积物砾石成分和古水流方向变化以及区域研究成果,表明若羌一带地块晚上新世以来发生阶段性逆时针旋转,推断阿尔金断裂构造带的左走滑特征可能形成于晚上新世以后.  相似文献   

15.
Shallow marine sequences of the northern South China Sea (SCS) are uplifted and exposed by plate convergence in the Taiwan mountain belt. These deposits provide detailed geological information about the rifting event, stratigraphy, sedimentology, paleoclimate and paleoceanography of the shallow SCS to compare with what are recorded in the ODP 1148 deep-sea core. Seismic surveys and marine micropalentological studies show that Eocene sequences in the offshore Taiwan Strait and onland Taiwan mountain belt are all deposited in rifting basins and are covered unconformably by the Late Oligocene-Neogene post-rifting strata. Between syn-rifting and post-rifting sequences, there is a regional break-up unconformity throughout the island. Early Oligocene and Late Eocene strata are missing along the break-up unconformity equivalent to the T7 unconformity in the Pearl River Mouth Basin off south China. This may suggest that the SCS oceanic crust could have initiated between 33 and 39 Ma. Neither obvious stratigraphic gap nor slumping features are found in the Oligocene-Miocene transition interval of Taiwan. This observation highly contrasts with what has been documented from the ODP 1148 deep-sea core. This suggests that the stratigraphic gap and slumping features could only be recorded in the SCS deep sea region, but not in the shallow shelf near Taiwan. Compared to the Middle Miocene paleoceanographic re-organization events in the SCS deep sea, the geological history of the Taiwan shallow sequence shows changes of in sedimentation and faunal composition. Due to the Antarctic glacial expansion at~14 Ma, Middle to late Miocene strata of the Western Foothills show progressive regression sedimentations associated with a decrease of benthic foraminif-eral abundance and a sharp faunal turnover event. Many Early-Middle Miocene endemic benthic foraminifers were extinct in 14-13 Ma and new benthic foraminifers of the Kuroshio Current fauna appeared from 10.2 Ma, comparable with new occurrence of Modern benthic foraminifers at 9 Ma in the Java Sea area. This reveals that the Western Boundary Kuroshio Current in the North Pacific could initiate from 10-9 Ma due to closures of the Indo-Pacific seaways by convergent tectonics between the Australian Continent and the Indonesian Arc in 12-8 Ma. Subduction of the SCS oceanic lithosphere since the Middle Miocene resulted in formation of the Hengchun Ridge accretionary prism and the North Luzon Arc. Occurrence of these two bathymetric highs ( 2400 m) since the Middle Miocene and closures of the inter-arc passages in the North Luzon arc in the last 3.5 Ma would control the water exchanges between the West Pacific and the deep SCS. Accordingly, the tectonic evolution in the Central Range-Hengchun Peninsula accretionary prism and the arc-forearc Coastal Range not only control directly the route for water exchanges between the West Pacific and the SCS, but also indirectly shows a great influence on the geochemistry of deep SCS waters. The latter is best shown by much negative carbon isotope values of benthic foraminifers in the ODP 1148 deep-sea core than the West Pacific records in the last 14 Ma.  相似文献   

16.
通过分析维也纳盆地的地层和断裂发育特征, 总结该盆地的石油地质特征, 并对该盆地的勘探潜力进行探讨。维也纳盆地是位于东阿尔卑斯与西喀尔巴阡褶皱带之间的走滑拉分盆地, 具有波西米亚和古生界至中生界双重基底, 构造演化分为侏罗纪伸展断陷、白垩纪至早中新世逆冲推覆和中新世中期盆地拉分3 个阶段。维也纳盆地自下而上形成3 个构造层, 分别为侏罗系至白垩系原地沉积层、二叠系至古近系外来推覆体沉积层和新近系沉积层。维也纳盆地发育上侏罗统泥灰岩和古近系页岩两套烃源岩, 上侏罗统启莫里阶Malmian 组泥灰岩是主要的烃源岩。储层分布于三叠系至新近系中新统的各个层段, 其中最重要的储层为中新统浅水三角洲相砂岩, 其油气储量占总储量的 76%, 其次为三叠系亮晶白云岩。区域盖层为新近系页岩。综合评价认为, 中生界外来推覆体(复理石浊积岩和三叠系白云岩)和原地中生界沉积物(即第二、第三构造层)是最重要的勘探潜力区。  相似文献   

17.
Fossil records indicate orangutan-like hominoids have been widely distributed in south China during Pleistocene, although currently only surviving in the tropical forests of Kalimantan and Sumatra in Indonesia. This paper describes the recently discovered hominoid fossil teeth from human site of Mulanshan cave in Chongzuo of Guangxi, whose geological age is the Late Pleistocene, about 11000 yeas age based on associated mammal fauna and U-series dating. Compared with those of modern and subfossil orangutans from Indonesia, other fossil great apes from China, the hominoid teeth from Mulanshan cave are orangutan-like, but show somehow different from Indonesia's orangutans, the average sizes of cheek teeth larger and occlusal enamel wrinkles less and simpler. They are classified temporarily as the subspecies of Pongo pygmaeus weidenreichi. Concerning the variations of morphological features and dental sizes of orangutan-like teeth from southern China and neighboring northern Vietnam, different subspecies or species or genus possibly, but the key evidence is necessary to be identified.  相似文献   

18.
The Middle Awash study area of Ethiopia's Afar rift has yielded abundant vertebrate fossils (approximately 10,000), including several hominid taxa. The study area contains a long sedimentary record spanning Late Miocene (5.3-11.2 Myr ago) to Holocene times. Exposed in a unique tectonic and volcanic transition zone between the main Ethiopian rift (MER) and the Afar rift, sediments along the western Afar rift margin in the Middle Awash provide a unique window on the Late Miocene of Ethiopia. These deposits have now yielded the earliest hominids, described in an accompanying paper and dated here to between 5.54 and 5.77 Myr. These geological and palaeobiological data from the Middle Awash provide fresh perspectives on hominid origins and early evolution. Here we show that these earliest hominids derive from relatively wet and wooded environments that were modulated by tectonic, volcanic, climatic and geomorphic processes. A similar wooded habitat also has been suggested for the 6.0 Myr hominoid fossils recently recovered from Lukeino, Kenya. These findings require fundamental reassessment of models that invoke a significant role for global climatic change and/or savannah habitat in the origin of hominids.  相似文献   

19.
本文基于北京平谷马坊地区Zk09钻孔新生代地层岩性岩相分析和沉积物古地磁等测试,建立了北京平原泃河水系中下游冲洪积区完整新生代地层格架。其中,0m~180m为中更新世-全新世陆相辫状河和曲流河沉积,180m~240.5m为中新世-上新世残坡积、湖积和三角洲前缘沉积。Zk09钻孔新生代不连续地层揭示了北京平原区两次重要的抬升构造事件:第一期构造事件发生于中新世,而不是前人研究认定的早更新世或上新世末,其最终结束了大渤海湾盆地古近纪盆-岭构造系统演化;第二次构造事件发生于中更新世早期,其可能是目前以走滑运动为主的最新构造变动形式起始时间。  相似文献   

20.
The Tertiary deposits of the Yongdeng section, the Lanzhou Basin were studied by means of magnetostrati-graphy. The magnetostratigraphic sequences from Paleocene to Miocene were established, and the time scale for the corresponding stratigraphy and mammalian faunas was also established by referring to their correlation to the GPTS of BKSA95 (The geomagnetic polarity time scale which was thoroughly revised and updated by Berggreen et al. in 1995). In the end the paleoenvironmental records and their relationship with the uplifting of the Tibetan Plateau were discussed. The results are as follows. The top boundary of the Xiliugou Formation is dated to be 51 Ma, i.e. Eocene. TheYehucheng Formation covers the time span of 51-31.5 Ma, i.e. from late Early Eocene to early Early Oligocene. The Xianshuihe Formation covers the time span of 31.5-15 Ma, i.e. from Early Oligocene to Middle Miocene. The lower member of the Xianshuihe Formation spans from 31.5 to 20.0 Ma, i.e. from Early Oligocene to early Early Miocene. The middle member is from 20.0 to 16.5 Ma, i.e. in the middle Early Miocene.  相似文献   

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