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1.
First middle Miocene sivaladapid primate from Thailand   总被引:1,自引:0,他引:1  
Sivaladapids are a group of Asian adapiform primates that were previously documented from deposits dating to the middle Eocene through the late Miocene in Pakistan, India, Myanmar, Thailand, and China. The group is notable for the persistence of three genera, Sivaladapis, Indraloris and Sinoadapis, into the late Miocene. In Thailand, sivaladapids were previously documented only from late Eocene deposits of the Krabi mine. Here, we describe the first Southeast Asian Miocene sivaladapid, Siamoadapis maemohensis gen. et sp. nov. from a 13.3 to 13.1 Ma lignite layer from the Mae Moh coal mine, Thailand. It differs from other Miocene sivaladapids by its distinctly smaller size and in features of the dentition. This discovery enhances the paleoecological diversity of the middle Miocene primate fauna of Thailand, which now includes sivaladapids, a loris, tarsiids, and hominoids. In this respect, the fossil primate community from the middle Miocene of Thailand is similar in its composition to roughly contemporaneous assemblages from southern China, India, and Pakistan. However, the Thai fossils represent a distinct genus, suggesting a different biogeographic province with distinctive paleoenvironments.  相似文献   

2.
The primate family, Amphipithecidae, lived during the early Cenozoic in South Asia. In this study, the diet of late middle Eocene amphipithecids from the Pondaung Formation (Central Myanmar) is characterized using three different approaches: body mass estimation, shearing quotient quantification and dental microwear analysis. Our results are compared with other Paleogene amphipithecids from Thailand and Pakistan, and to the other members of the primate community from the Pondaung Formation. Our results indicate a majority of frugivores within this primate community. Pondaungia and “Amphipithecus” included hard objects, such as seeds and nuts, in their diet. Folivory is secondary for these taxa. Myanmarpithecus probably had a mixed diet based on fruit and leaves. Contrasting results and a unique dental morphology distinguish Ganlea from other amphipithecids. These render interpretation difficult but nevertheless indicate a diet tending towards leaves and fruit. However, the anterior dentition of Ganlea suggests that this taxon engaged in seed predation, using its protruding canine as a tool to husk hard fruits and obtain the soft seeds inside. Bahinia and Paukkaungia, two other Pondaung primates, are small (<500 g) and therefore would have depended on insects as their source of protein. As such, they occupied a very different ecological niche from Pondaung amphipithecids. This primate community is then compared with the Eocene-Oligocene primate communities of the Fayum from North Africa. Similarities between the late middle Eocene Pondaung primate community and extant equatorial and tropical South American primate communities are noted.  相似文献   

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The muroid Cricetops Matthew and Granger, 1923 commonly occurred in the Oligocene terrestrial deposits in central and northern Asia. Here we report the first record of Cricetops in the southern part of Asia. Isolated rodent molars named as a new species, Cricetops auster sp. nov., were discovered from the early Oligocene sediments at the Lijiawa locality in Yunnan Province in southwestern China. Compared to previously known Cricetops, C. auster is smaller than Cricetops dormitor Matthew and Granger, 1923 and Cricetops aeneus Shevyreva, 1965, but larger than Cricetops minor Wang, 1987. The cusps of C. auster are less conical. The ridges and crests are longer, higher and thicker. Relatively long and high crests, ridges and arms extending from the main cusps in the new species make those cusps more crescent in appearance than in C. dormitor, C. aeneus and C. minor. C. auster is a rare species in the Lijiawa mammalian fauna. Well-developed shearing tooth crests and ridges of C. auster probably suggest a different diet from the Cricetops from the northern part of Asia.  相似文献   

5.
A fifth anthropoid (= anthropoidean, simian or simiiform) genus and species from the late Eocene Fayum Quarry L-41, Abuqatrania basiodontos gen. et sp. nov., further augments the already remarkable primate diversity from this locality and provides the first convincing extension of the enigmatic family Parapithecidae into the oldest productive vertebrate fossil-bearing stratum of the Jebel Qatrani Formation. A. basiodontos exhibits no clear autapomorphies nor any apomorphies that are shared exclusively with any other parapithecid species, and it is most parsimoniously interpreted as the sister taxon of a Qatrania-Parapithecus-Apidium clade. Reevaluation of two contemporaries of A. basiodontos, Serapia and Arsinoea, suggests that neither genus should be ranked as a basal parapithecid. Serapia is more derived than primitive parapithecids in the morphology of the lower fourth premolar and exhibits greater overall similarity to Proteopithecus in cusp placement and the shape and proportions of its lower teeth; accordingly, we place Serapia in the family Proteopithecidae. Arsinoea is much more problematic and does not fit well with any hitherto known Afro-Arabian anthropoid group; we place this genus in a new anthropoid family, Arsinoeidae.  相似文献   

6.
The species Proconsul (Xenopithecus) hamiltoni was based on two weathered molars in a maxillary fragment from the Erageleit beds, Lothidok, Turkana District, Kenya. New fossils from Lothidok show a unique suite of features indicating generic distinction of this taxon from other known large early catarrhines. A new generic diagnosis is given. The new genus, although still poorly known, may be the first Oligocene hominoid from East Africa. It retains many primitive features, but the few derived ones hint that it may be related to the Afropithecus group.  相似文献   

7.
We report the discovery of two new primates from the late Eocene Krabi Basin, southern Thailand. One isolated upper molar displays morphological features (protocone united with hypocone by the prehypocrista, postprotocrista extended distobuccally) suggesting possible phylogenetic relationships with Amphipithecidae, while an isolated lower molar is tentatively referred to as a new tarsiiform, mainly on the basis of its paraconid and entoconid morphology. Although very scarce, these remains expand the record of Paleogene primates in Southeast Asia, and testify to their successful radiation in that area.  相似文献   

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Frontal and lateral intraoral photographs of 19 baboons from the Awash National Park, Ethiopia and 37 baboons from Amboseli National Park, Kenya, were used to assess periodontal health. The Awash baboons, and two groups (Alto's and Hook's) at Amboseli, fed entirely from natural sources, but baboons from the third Amboseli group (Lodge) fed largely on food refuse from one of the park's lodges. Juveniles and adults were evaluated separately. Intraoral photographs were seriated based on visual appraisals of periodontal health. In both age groups, the best periodontal health was seen in Awash animals; Alto's and Hook's animals were intermediate, and the poorest health was seen in the Lodge sample. The periodontal health decreased with age in adult baboons, as reported in humans. Geochemistry, genetics, age, and diet (particularly variations in bacterial flora) were considered as factors contributing to the intergroup differences. Although it is not possible at present to exclude any of these as a contributing cause, we consider that diet in the broad sense (including food, water, and contamination by oral bacteria of human origin) probably plays a major role. © 1993 Wiley-Liss, Inc.  相似文献   

12.
An isolated petrosal bone belonging to a diminutive primate is reported from Middle Eocene fissure-fills near Shanghuang (southern Jiangsu Province, People's Republic of China), the type locality of several newly described primates (Eosimias sinensis, a basal anthropoid; Adapoides troglodytes, a basal adapinan; Tarsius eocaenus, a congener of extant tarsiers; and Macrotarsius macrorhysis, the first Asian representative of an otherwise exclusively North American genus). Because of its fragmentary condition and unique combination of characters, the Shanghuang petrosal cannot be assigned unambiguously to any of the Shanghuang primate taxa known from dental remains. However, the possibility that the petrosal represents either an adapid or a tarsiid can be dismissed because it lacks defining basicranial apomorphines of these groups. By contrast, the element does present arterial features consistent with its being haplorhine. Deciding between the likeliest candidates for its allocation—Omomyidae and Eosimiidae—is difficult, in part because it is not known what (or even whether) basicranial characters can be used to distinguish these clades. If the Shanghuang petrosal is that of an cosimiid, as both direct and indirect evidence appears to indicate, the following implications emerge: (1) as long suspected on other grounds, anthropoids share a closer evolutionary history with Omomyidae (and Tarsiiformes) than they do with Adapidae (and Strepsirhini); (2) the specialised basicranial anatomy of extant anthropoids and their immediate cladistic relatives is derived from a primitive precursor whose otic morphology was like that of omomyids in most known respects; (3) the evolution of the defining dental and basicranial apomorphies of extant Anthropoidea has been distinctly mosaic in pattern.  相似文献   

13.
From 1980–1985, the Turkana District of Kenya experienced both drought and above average rainfall. The effects of a 2-year drought on the livestock population of the nomadic pastoral Ngisonyoka are discussed. Detailed data on mortality rates and offtake are presented for the animals of four herd owners, and the recovery process is followed for the 5-year period for one herd owner. It is concluded that during the drought, 63% of the cattle, 45% of the camels, and 55% of the small stock left the sample herds. The livestock population of one herd had recovered to pre-drought levels 3 years after the drought.  相似文献   

14.
Plio-Pleistocene East African grassland expansion and faunal macroevolution, including that of our own lineage, are attributed to global climate change. To further understand environmental factors of early hominin evolution, we reconstruct the paleogeographic distribution of vegetation (C(3)-C(4) pathways) by stable carbon isotope (delta(13)C) analysis of pedogenic carbonates from the Plio-Pleistocene Koobi Fora region, northeast Lake Turkana Basin, Kenya. We analyzed 202 nodules (530 measurements) from ten paleontological/archaeological collecting areas spanning environments over a 50-km(2) area. We compared results across subregions in evolving fluviolacustrine depositional environments in the Koobi Fora Formation from 2.0-1.5 Ma, a stratigraphic interval that temporally brackets grassland ascendancy in East Africa. Significant differences in delta(13)C values between subregions are explained by paleogeographic controls on floral composition and distribution. Our results indicate grassland expansion between 2.0 and 1.75 Ma, coincident with major shifts in basin-wide sedimentation and hydrology. Hypotheses may be correct in linking Plio-Pleistocene hominin evolution to environmental changes from global climate; however, based on our results, we interpret complexity from proximate forces that mitigated basin evolution. An approximately 2.5 Ma tectonic event in southern Ethiopia and northern Kenya exerted strong effects on paleography in the Turkana Basin from 2.0-1.5 Ma, contributing to the shift from a closed, lacustrine basin to one dominated by open, fluvial conditions. We propose basin transformation decreased residence time for Omo River water and expanded subaerial floodplain landscapes, ultimately leading to reduced proportions of wooded floras and the establishment of habitats suitable for grassland communities.  相似文献   

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Tropodiaptomus turkanae sp. nov. is described from Lake Turkana (formerly Lake Rudolph), Kenya. After years of confusion with T. banforanus , the identity of this taxon as an endemic of Lake Turkana is established. The species is described, and its relationship with other Tropodiaptomus species discussed.  相似文献   

17.
Summary Presented here is a record of a piciform bird from a late Oligocene fissure filling from Germany. This is the earliest known fossil record of a modern-type piciform bird and the only one from deposits earlier than Miocene. The specimen, an isolated tarsometatarsus, is similar in size and proportions to the tarsometatarsus of the recent Cardinal-Woodpecker (Dendropicos fuscescens, Picidae). However, owing to its fragmented state a reliable assignment to any of the recent piciform families is not possible.
Der älteste Nachweis eines modernen Spechtvogels aus dem späten Oligozän Deutschlands
Zusammenfassung Ein Nachweis eines Spechtvogels wird aus einer spätoligozänen Spaltenfüllung Deutschlands beschrieben. Es ist der bisher älteste Nachweis eines modernen Spechtvogels und der einzige aus vor-miozänen Ablagerungen. Das Exemplar, ein isolierter Tarsometatarsus, ähnelt in Größe und Proportionen dem Tarsometatarsus des rezenten Kardinalspechts (Dendropicos fuscescens, Picidae). Aufgrund seiner fragmentarischen Erhaltung ist jedoch keine zuverlässige Zuordnung zu einer der rezenten Familien spechtartiger Vögel möglich.
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Craspedacusta sowerbyi Lankester is confined mainly to the Holarctic region and Limnocnida tanganyicae Gunther to the Afrotropical region. In the summer of 1978, C. sowerbyi appeared in large numbers in the plankton of an isolation column which had been established in Lake Midmar, an oligotrophic warm-temperate lake in the Natal midlands, South Africa. A review of the literature indicates that since 1930, C. sowerbyi has extended its range into the southern hemisphere where it occurs sporadically.  相似文献   

20.
The incidence of agenesis and polygenesis in the primate dentition   总被引:1,自引:0,他引:1  
The incidence of dental agenesis and polygenesis was demonstrated in 978 Old World monkeys, 390 great apes, 194 lesser apes and 5,000 humans of Caucasoid and Negroid stock. The frequency of agenesis was highest in the human sample, particularly in the Negroids, that of polygenesis was highest in the great apes. Within both groups, the polymorphism was commonest in the molar (predominantly third molar) region. Despite numerous difficulties in the interpretation of such data, on the basis of the differences between man, apes and monkeys, it is suggested that the high incidence of agenesis seen in man is a phylogenetic accompaniment of the shortening of the maxillomandibular skeleton, which is such a marked feature of human evolution.  相似文献   

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