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1.
A new fossil species,Hemiptelea mikii, is described on the basis of fruits from the Pleistocene of central Japan. It is distinguished fromH. davidii, the only extant species of the genus restricted to Korea and China, in having shorter fruits. Fossil woods discovered from the same horizon differ from the extant one in some anatomical characteristics, and are assigned to the new fossil species. Taken together with earlier records of fossil fruit occurrence in the early and the middle Pleistocene of central Japan, the latest finding of fossil fruits and woods from the last glacial sediments (ca. 50,000 years ago) at Kita-egota site of Tokyo suggests thatH. mikii was widespread in central Japan throughout the Pleistocene and survived until as late as the Last Glacial age.  相似文献   

2.
Fossils of Pleistocene mammals have been discovered in the southern Brazilian coastal area since the late XIX century, in two main places: the continental shelf and the Chuí Creek. Although the taxonomic composition of fossil assemblages from these areas has been the focus of most studies during the late XX century, research concerning the ages, stratigraphic position, and biostratigraphy of such assemblages remains scarce. This is due to the lack of suitable materials for age determination and the reworked nature of the fossiliferous deposits in the continental shelf. Only in recent years have new data shed light on these subjects. Taxonomic revisions, ESR ages, and biostratigraphic correlations confirm a late Pleistocene age for the fossil assemblages, although those from the shelf represent a significant time averaging, while fossils from the Chuí Creek exhibit a narrower age range. The fossil mammals found in southern Brazil represent a mixture of Brazilian and Pampean taxa, including forms that disappeared much earlier from the Argentinean pampas. Gaining an understanding of the biostratigraphic context of such assemblages in comparison to similar assemblages from Argentina and Uruguay, in conjunction with stratigraphic, geomorphological, and paleoclimatic data should provide additional tools with which to reconstruct the environmental and climatic dynamics of this portion of South America during the late Pleistocene—early Holocene and its effects on the fauna, and possibly to help address the problem of the disappearance of megamammals in the area.  相似文献   

3.
South America was isolated from other continents during most of the Cenozoic, developing a singular mammalian fauna. In contrast to North America, Europe, Asia, and Africa, up to the late Neogene, the carnivore adaptive zone in South America was populated by crocodiles (Sebecidae), large snakes (Madtsoiidae), large birds (Phorusrhacidae), and metatherian mammals (Sparassodonta). Sparassodonta were varied and comprised a wide range of body masses (≈ 2–50 kg) and food habits. Their diversity decreased towards the late Miocene (Huayquerian Stage/Age) and the group became extinct in the “middle” Pliocene (≈ 3 Ma, Chapadmalalan Stage/Age). Several authors have suggested that the cause of this decline and extinction was the ingression of carnivorans to South America (about 6–7 Ma ago), because they competed with the Sparassodonta; although this hypothesis has been criticized in recent years. With the intention of testing the hypothesis of “competitive displacement,” we review the fossil record of South American Sparassodonta and Carnivora, collect data about diversity, estimate size and diet, and determine first and last appearances. The diversity of Sparassodonta is low relative to that of Carnivora throughout the Cenozoic with the early Miocene (Santacrucian Stage/Age) showing the greatest diversity with 11 species. In the late Miocene-middle Pliocene (Huayquerian Stage/Age), the fossil record shows overlap of groups, and the Sparassodonta’s richness curve begins to decline with the first record of Carnivora. Despite this overlap, carnivorans diversity ranged from four or fewer species in the late Miocene-Pliocene to a peak of around 20 species in the early Pleistocene (Ensenadan Stage/Age). Carnivora was initially represented by small-sized, omnivorous species, with large omnivores first appearing in the Chapadmalalan Stage/Age. Over this period, Sparassodonta was represented by large and small hypercarnivores and a single large omnivorous species. From this review of the fossil record, it is suggested that factors other than competitive displacement may have caused the extinction of the Sparassodonta.  相似文献   

4.
周口店更新世鸟类化石   总被引:3,自引:0,他引:3  
<正> 北京市房山县周口店更新世洞穴,尤其北京猿人产地的第一地点(Loc.1)富含鸟类化石。自1927年开始至1980年采获的鸟类化石多达万件。同北京猿人相伴生的周口店脊椎动物群,是我国北方第四纪动物群的主要代表。近半个世纪来,中外学者,除对周口店人类化石、文化遗迹等进行过不少详细的研究,也对脊椎动物化石,主要是哺  相似文献   

5.
Providing an underutilized source of information for paleoenvironmental reconstructions, birds are rarely used to infer paleoenvironments despite their well-known ecology and extensive Quaternary fossil record. Here, we use the avian fossil record to investigate how Western Palearctic bird assemblages and species ranges have changed across the latter part of the Pleistocene, with focus on the links to climate and the implications for vegetation structure. As a key issue we address the full-glacial presence of trees in Europe north of the Mediterranean region, a widely debated issue with evidence for and against emerging from several research fields and data sources. We compiled and analyzed a database of bird fossil occurrences from archaeological sites throughout the Western Palearctic and spanning the Saalian-Eemian-Weichselian stages, i.e. 190,000–10,000 years BP. In general, cold and dry-adapted species dominated these late Middle Pleistocene and Late Pleistocene fossil assemblages, with clear shifts of northern species southwards during glacials, as well as northwards and westwards shifts of open-vegetation species from the south and east, respectively and downwards shifts of alpine species. A direct link to climate was clear in Northwestern Europe. However, in general, bird assemblages more strongly reflected vegetation changes, underscoring their usefulness for inferring the vegetation structure of past landscapes. Forest-adapted birds were found in continuous high proportions throughout the study period, providing support for the presence of trees north of the Alps, even during full-glacial stages. Furthermore, the results suggest forest-dominated but partially open Eemian landscapes in the Western Palearctic, including the Northwestern European subregion.  相似文献   

6.
《Geobios》1986,19(6):755-772
To date very little is known of the history of birds in China, Japan and all of Southeast Asia (Brodkorb 1963, 1964, 1967, 1971, 1978; Kurotchkin 1976; Young 1932, 1975). Early Cretaceous birds have been recovered from Gansu Province in western China. A single bird bone has also been recovered marine Cretaceous sediments in Japan. Most of the early Cenozoic records are of gruiform birds, while late Cenozoic records constitute a variety of taxa, including some forms closely related to, or congeneric with, Struthio, as well as ducks (Anatidae), game birds (Galliformes), a few birds of prey (Falconiformes) and doves (Columbidae), so the length of the record is long, though not particularly rich.Recently work by Hou has vastly increased thediversity of Pleistocene birds from China, particularly from the Peking Man Site (Zhoukoudian) in North China. Yeh's analysis of four nearly complete avian skeletons from Miocene-aged caldera lake deposits of Shandong Province in central China, has given a better idea of whole animal biology of several groups of birds in the Oriental Realm, especially for the game birds. Hasegawa's, Ono's, and Olson's work on Japanese fossil birds is rapidly adding to knowledge from that area as well. Because of the current increased field activity, refined field techniques, and developing interest in fossil birds in both China and Japan, the quality of the record has increased markedly in the last five years.Fossil birds are extremely rare in the remainder ofSoutheast Asia and most are of Pleistocene age. Reanalysis of Protoplotus beauforti from early to mid-Cenozoic lacustrine sediments of Sumatra, by, van Tets, Rich, & Marino, suggests that it belongs in a family of its own within the Pelecaniformes.  相似文献   

7.
Pleistocene rhinoceroses are poorly documented in Turkey where they have been reported only from the late early Pleistocene (1.3–1.1 Ma) travertine deposits of the Denizli Basin. In this work, new rhinoceros remains collected from this basin are assigned to a relatively large-sized Stephanorhinus hundsheimensis on the basis of their morphology and morphometry. The first Turkish record of this species is approximately coeval with the first appearance of Shundsheimensis in Europe, chronologically referred to the late early Pleistocene, ca. 1.2 Ma. During that time, Setruscus still survived in Iberian Peninsula, central Italy and Dacian Basin. The presence of two successive evolutionary morphs for Shundsheimensis during the Pleistocene is not confirmed.  相似文献   

8.
The fossil record of vertebrate tracks in Mexico is taxonomically rich and geographically diverse, and ranges in age from Middle Jurassic to Pleistocene and possibly Holocene. Middle Jurassic saurischian dinosaur tracks from Oaxaca represent the oldest record of vertebrate tracks in Mexico. Tracks attributed to Late Jurassic theropods and ornithopods are known from Michoacán. Theropod tracks of supposed Jurassic age are known from Durango. Lower Cretaceous Saurischian and ornithopod tracks are known from southern Puebla. Central Mexico has yielded Late Cretaceous hadrosaurid and sauropod tracks (Puebla), and tracks belonging to Theropoda and Ornithopoda (El Aguaje, Michoacan). In Coahuila several tracksites occur within the Cerro del Pueblo Formation and include tracks of mesoreptiles, pterosaurs, small to large theropods, bipedal and quadrupedal ornithopods, birds and possibly a mammal. A tracksite in the Olmos Formation includes tracks of turtles, crocodilians, medium-sized theropods, small ornithopods, and birds. Bird tracks of supposed Eocene age are known from Sinaloa. Two important Pleistocene ichnofaunas occur in the states of Puebla (Tepexi de Rodríguez) and Jalisco (San Juan de los Lagos), and include tracks of camelids, artiodactyls, small ungulates, elephants, large felids and birds. Pleistocene human tracks occur in Coahuila and Jalisco. Mexico's track record provides important insights into vertebrate diversity, paleoecology, and paleoenvironments. Given the rate of new discoveries since 1998, there is no doubt that new sites await to be found.  相似文献   

9.
Jablonski and Tyler (1999) announced a new subspecies of colobine monkey based on a fossil partial maxilla from the Sangiran dome. The specimen is easily assigned to a living leaf monkey species—most extant Southeast Asian catarrhines differ only subspecifically from their Middle Pleistocene earliest local fossil ancestors. Yet Jablonski and Tyler (1999) reported an improbable provenance for the specimen; a mass-flow volcanic breccia generally considered late Pliocene in age. We show that the Lower Lahar was laid down amidst a range of paludal habitats and that its deposition predates the appearance of all-but-now extinct, water-tolerant mammals on emergent Java. No other catarrhine fossil has been ascribed to the Lower Lahar, not even hominins, which are the most gregarious members of the group. More probable provenance lies in the upper Sangiran or the lower Bapang formations. Either alternative would associate the specimen with other catarrhine fossils in more tenable Pleistocene environments. We also unravel errors and inconsistencies in the contextual report and in the discussion of dome geochronology. The various radiometric, paleomagnetic, and paleontologic studies cited show a discordance of about 300 Ka (thousand years) across the lithostratigraphic sequence. Plio-Pleistocene biogeographic hypotheses for Java must work with short and long chronologies.  相似文献   

10.
The age and geographical distribution of fossil cercopithecids in China   总被引:2,自引:0,他引:2  
Cercopithecids did not arrive in China until the latest Tertiary, relatively late in their evolutionary history. Cercopithecines are represented in the Chinese fossil record by two genera,Procynocephalus andMacaca, both of which made their appearance in the Late Pliocene or Early Pleistocene, but only one of which,Macaca, was widely distributed throughout the Quaternary and remains in the country today. The much less well known genusProcynocephalus disappeared from China in the late Early Pleistocene, but is of considerable interest because it appears to have been part of a radiation of large terrestrial cercopithecines that extended throughout portions of southern and eastern Asia. Colobines are poorly represented in the fossil record of China. Aside from a few scattered occurrences ofRhinopithecus in the Middle and Late Pleistocene records of southern China, the subfamily is represented by only one other intriguing specimen. This is the large and nearly complete mandible now classified as «Megamacaca lantianensis» from the Gongwangling locality of Lantian, Shaanxi Province. The specimen was retrieved from sediments of late Early Pleistocene age and was associated with elements of a typical southern,Ailuropoda — Stegodon fauna. The distribution of cercopithecids, especiallyMacaca, in China followed the southern and eastern retreat of subtropical habitats during the course of the Pleistocene.  相似文献   

11.
广西柳江土博出土的人牙化石及共生的哺乳动物群   总被引:6,自引:2,他引:4  
在广西柳江县土博公社发现一洞穴,地层中含有人类化石和哺乳动物化石。其时代初步定为更新世晚期。人类化石仅是牙齿九枚,根据其形态特征,这些材料的系统地位似应与柳江人相当,分类上可归属晚期智人。  相似文献   

12.
A better understanding of the evolutionary relationship between modern humans and Neanderthals is essential for improving the resolution of hominin phylogenetic hypotheses. Currently, four distinct chronologies for the timing of population divergence are available, ranging from the late Middle Pleistocene to the late Early Pleistocene, each based on different interpretations of hominin taxonomy. Genetic data can present an independent estimate of the evolutionary timescale involved, making it possible to distinguish between these competing models of hominin evolution. We analysed five dated Neanderthal mitochondrial genomes, together with those of 54 modern humans, and inferred a genetic chronology using multiple age calibrations. Our mean date estimates are consistent with a process of genetic divergence within an ancestral population, commencing approximately 410-440 ka. These results suggest that a reappraisal of key elements in the Pleistocene hominin fossil record may now be required.  相似文献   

13.
14.
Diversification patterns and demography of montane species are affected by Pleistocene climate fluctuations. Empirical cases from the Qinling Mountains (QM) region, which is a major biogeographic divider of East Asia, are few. We used DNA sequence data of the complete mitochondrial ND2 gene to detect effects of the Pleistocene glaciations on phylogeographic profiles of a frog species, Feirana taihangnica, which is endemic to the QM. Four distinct lineages consisting of seven sublineages were revealed. The strongest signal of biogeographical structure (F ct = 0.971, P < 0.01) was found when populations were grouped according to these seven sublineages. One narrow secondary contact zone was detected in the middle QM between the lineage from middle QM and the lineage from eastern QM. Coalescent simulations indicated that this species colonized the QM region by a stepping-stone model. Divergences among lineages had likely been influenced by the uplift of the Tibetan Plateau during the late Miocene-to-late Pleistocene, as well as by the Pleistocene climatic cycles. Coalescent simulations also suggested that F. taihangnica populations have persisted through the Pleistocene glacial periods in multiple refugia across the QM region. Demographic analyses indicated that all lineages, except the lineage in the Funiu Mountains, have been experienced postglacial expansion of population size and distribution range. In conclusion, Pleistocene climate fluctuations and tectonic changes during the late Miocene-late Pleistocene have profoundly influenced the phylogeography and historical demography of F. taihangnica.  相似文献   

15.
Catagonus wagneri has the most restricted geographical distribution among extant Tayassuidae and inhabited semi-arid thorny forests of dry Chaco in Paraguay, Bolivia and Argentina. Until now, C. wagneri has only been recorded in archaeological, pre-Hispanic deposits from the Santiago del Estero Province, Argentina. A new partially complete skull from the Sopas Formation (Late Pleistocene; Uruguay) is identified as C. wagneri. This is the only fossil record of the species which extends its biochron until the late Pleistocene, and the first one substantially far from its current range; the first fossil record of the species in Uruguay; the most complete fossil material of the species; and it provides relevant ecological and climatic information. According to the ecological and climatic available information of C. wagneri, the presence of this mammal in the late Pleistocene of northern Uruguay indicates a warm climate and arid to semi-arid environments. Even though not associated with the fossil remains of C. wagneri, some mammals included in the sedimentary levels of the Sopas Formation also suggest arid to semi-arid environments. Climatic changes, in particular in the late Pleistocene and Holocene, could be invoked to explain modifications of its geographic range.http://zoobank.org/ECF04BCF-8246-4F11-AAB8-5FAA9F437BDA  相似文献   

16.
Two macaque fossil teeth from the Japanese Pleistocene   总被引:3,自引:3,他引:0  
Two fossil teeth of the Pleistocene macaque of Japan are stated to be those ofMacaca cf.fuscata. One of them is a lower canine tooth found in the Shiriya mine in northern Japan. It has been thought that the fossil assemblage of the Shiriya mine is of the late Pleistocene. The canine concerned is not distinguishable from the lower right one of the living female Japanese monkey. The other is a lower molar taken from the Ando quarry in western Japan. The fossil assemblage from the Ando quarry or from sites neighbouring the quarry indicates that the age of the molar can be traced back to the middle Pleistocene. The molar concerned has a somewhat buccolingually depressed crown as compared with that of the living Japanese monkey (Macaca fuscata).  相似文献   

17.
四川盐源盆地哺乳类化石及其意义   总被引:5,自引:0,他引:5  
本文简述盐源盆地上新世和更新世晚期两个不同时代的哺乳动物化石十余种,据之修正了该盆地晚新生代沉积的时代和对比关系.  相似文献   

18.
This article discusses the results of a taxonomic and ecological investigation of diatoms from polygonal ponds and Quaternary permafrost deposits of Bol’shoy Lyakhovsky Island (New Siberian Archipelago) and the reconstruction of climatic changes on the Island during late Pleistocene/Holocene transition using fossil diatom assemblages from the permafrost deposits. The taxonomic list of diatoms includes 159 diatom species. The main ecological factors that determine the distribution of diatoms in the investigated data set are mean July air temperature, рН, electrical conductivity, water depth, and concentrations of Si4+ and Al3+. An increase in water depth and stable lacustrine conditions in the Lateglacial–Holocene in the ancient thermokarst lake relate to Lateglacial warming before 11860 ± 160 years BP and during the early Holocene between 11210 ± 160 and 7095 ± 60 years BP.  相似文献   

19.
The rhinoceros remains collected during the past century in the lower levels XII (= K) and XI (= I) of the famous Pleistocene locality of Grotta Romanelli (Lecce, southern Italy) are described and compared in detail for the first time. Some remains are referred to Stephanorhinus sp. and others are assigned here to the late early-middle Pleistocene European species Stephanorhinus hundsheimensis based on several morphological characters. Based on its olivine-bearing texture, the volcanoclastic ash sampled from some rhinoceros bones can be referred to the first phase of the Monte Vulture activity (around 630 ka). The results of the stable isotope analyses suggest that the climate in the lowest levels of Grotta Romanelli could have been more arid than it was at the time of the upper level IX, which is generally referred to the late Pleistocene. In addition, both recent day δ18Oppt values and MAT are very similar to values calculated for levels X and XII, suggesting that the climate at those times may have been close to the Present one, whereas climate in level IX may have been somewhat cooler. The presence of Stephanorhinus hundsheimensis suggests a middle Pleistocene age for the lower levels of Grotta Romanelli, in agreement with the results obtained from the volcanoclastic material.  相似文献   

20.
湖南省西北部新发现的哺乳动物化石及其意义   总被引:9,自引:2,他引:7  
本文记述了在慈利县发现的金丝猴下颌骨化石标本。报道了吉首县螺丝旋山洞出土的可能是更新世晚期的哺乳动物化石及其地层的情况;比较详细地研究了早更新世晚期的保靖县洞泡山动物群。并描述了大熊猫的一个新亚种——武陵山亚种。进一步证实在华南存在一个从柳城巨猿洞动物群向狭义的“大熊猫-剑齿象动物群”过渡类型的动物群。以上新发现的更新世哺乳动物化石及其地层对于湖南(尤其是湘西)第四纪的研究提供了重要资料  相似文献   

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