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1.
Kolpochoerus (Mammalia: Suidae) is a suine genus represented by a number of species from Plio-Pleistocene sites in Africa. While the general trends in Kolpochoerus evolution are broadly known, gaps in the fossil record preclude an understanding of the details of its evolutionary tempo and mode. Here, we describe a new species, Kolpochoerus millensis, based on new fossil material from the Woranso-Mille and Gona sites in the Central Afar region of Ethiopia and dated to 3.5–3.8 million years ago (Ma). Third molars of K. millensis are metrically and morphologically intermediate between the early Pliocene K. deheinzelini and earliest late Pliocene K. afarensis. It appears that K. deheinzelini, K. millensis, and K. afarensis are temporally disjunct and phenetically distinguishable parts of a single evolving lineage. The recognition of these chronospecies provides additional evidence for anagenetic evolution. It demonstrates clearly the presence of transitional forms in the fossil record. The extensive and well-dated Kolpochoerus fossil record serves as one of the best documented examples of the occurrence of phyletic evolution. Moreover, K. millensis is one of the best biochronological markers in eastern Africa for the time between 3.5 and 3.8 Ma.  相似文献   

2.
We report here the discovery of madtsoiid snake remains from the early Paleocene Khadro Formation (Ranikot Group, Sindh, Southern Pakistan). These specimens consist of vertebrae and are referred to Gigantophis. This is the first report of Gigantophis from outside of Africa. The problem of the generic distinction between Gigantophis and Madtsoia is stressed. The specimens from Pakistan slightly differ from the single species (Ggarstini) referred to the genus Gigantophis, but the available material does not allow further considerations and the fossil is referred to as Gigantophis sp. However, Gigantophis sp. from the Khadro Formation is more closely related to Ggarstini, that is known only from the middle and late Eocene of northern Africa, than to any other species, thus suggesting dispersal between these two areas during the Paleocene or earlier. These results are consistent with the hypothesis of intermittent dispersals between the Indo-Pakistan Plate and Africa suggested by other fossil evidences.  相似文献   

3.
Recent fossil discoveries have demonstrated that Africa and Asia were epicentres for the origin and/or early diversification of the major living primate lineages, including both anthropoids (monkeys, apes and humans) and crown strepsirhine primates (lemurs, lorises and galagos). Competing hypotheses favouring either an African or Asian origin for anthropoids rank among the most hotly contested issues in paleoprimatology. The Afrocentric model for anthropoid origins rests heavily on the >45 Myr old fossil Algeripithecus minutus from Algeria, which is widely acknowledged to be one of the oldest known anthropoids. However, the phylogenetic position of Algeripithecus with respect to other primates has been tenuous because of the highly fragmentary fossils that have documented this primate until now. Recently recovered and more nearly complete fossils of Algeripithecus and contemporaneous relatives reveal that they are not anthropoids. New data support the idea that Algeripithecus and its sister genus Azibius are the earliest offshoots of an Afro–Arabian strepsirhine clade that embraces extant toothcombed primates and their fossil relatives. Azibius exhibits anatomical evidence for nocturnality. Algeripithecus has a long, thin and forwardly inclined lower canine alveolus, a feature that is entirely compatible with the long and procumbent lower canine included in the toothcomb of crown strepsirhines. These results strengthen an ancient African origin for crown strepsirhines and, in turn, strongly challenge the role of Africa as the ancestral homeland for anthropoids.  相似文献   

4.
A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.  相似文献   

5.
A new species of Firmiana Marsili is recognized and described based on capsules from the Late Miocene Lincang flora of Yunnan, China. Firmiana yunnanensis nov. sp. is represented by opened, dehiscent, membranous follicles with a weak, sinuous midvein, obtuse secondary veins and thick marginal vein. The follicles conform in shape and venation with those of extant species of Firmiana, a genus now distributed in eastern Africa, Indo-Malaysia, and eastern and southeastern Asia. This fossil species occurred within the native distribution of extant Firmiana species. It provides new information on fossil history, paleoecology, as well as on the plant diversity of the Lincang flora.  相似文献   

6.

Background

The family Phyllanthaceae has a predominantly pantropical distribution. Of its several genera, Bridelia Willd. is of a special interest because it has disjunct equally distributed species in Africa and tropical Asia i.e. 18–20 species in Africa-Madagascar (all endemic) and 18 species in tropical Asia (some shared with Australia). On the basis of molecular phylogenetic study on Bridelia, it has been suggested that the genus evolved in Southeast Asia around 33±5 Ma, while speciation and migration to other parts of the world occurred at 10±2 Ma. Fossil records of Bridelia are equally important to support the molecular phylogenetic studies and plate tectonic models.

Results

We describe a new fossil leaf of Bridelia from the late Oligocene (Chattian, 28.4–23 Ma) sediments of Assam, India. The detailed venation pattern of the fossil suggests its affinities with the extant B. ovata, B. retusa and B. stipularis. Based on the present fossil evidence and the known fossil records of Bridelia from the Tertiary sediments of Nepal and India, we infer that the genus evolved in India during the late Oligocene (Chattian, 28.4–23 Ma) and speciation occurred during the Miocene. The stem lineage of the genus migrated to Africa via “Iranian route” and again speciosed in Africa-Madagascar during the late Neogene resulting in the emergence of African endemic clades. Similarly, the genus also migrated to Southeast Asia via Myanmar after the complete suturing of Indian and Eurasian plates. The emergence and speciation of the genus in Asia and Africa is the result of climate change during the Cenozoic.

Conclusions

On the basis of present and known fossil records of Bridelia, we have concluded that the genus evolved during the late Oligocene in northeast India. During the Neogene, the genus diversified and migrated to Southeast Asia via Myanmar and Africa via “Iranian Route”.  相似文献   

7.
This study presents the discovery of a right cercopithecine calcaneus from the site of ‘Ubeidiya, Israel, dated to ca. 1.6 Ma. The fossil is described and statistically compared to bones of modern and fossil cercopithecids. The specimen can be attributed to a large-bodied cercopithecine and represents a new primate taxon previously unidentified in the Early Pleistocene of the Southern Levant. Among extant genera, it is most clearly similar to calcanei of Theropithecus. However, it could also represent Paradolichopithecus, but this alternative is unlikely due to the morphological uniqueness of the latter taxon.The finding of an African taxon in the Levant suggests a circum-Mediterranean dispersal route for the taxon out of Africa, and emphasizes the importance of the Levantine corridor as a biogeographic dispersal route between Africa and Eurasia during the Early Pleistocene. Evidence for the biogeography of large-bodied primates is essential for the understanding of the dispersal routes of “Out of Africa I” taxa and can help elucidate Homo dispersal patterns in the Early Pleistocene.  相似文献   

8.
A silicified wood belonging to the Lauraceae family discovered in Africa (Cameroon) is referred to the new genus Beilschmiedioxylon. The important literature concerning the woods of this family shows some difficulties in characterizing the woods of recent genera and, consequently, the fossil ones. So, an inventory of all the Lauracean fossil woods with new precisions and discussions seems to be necessary. This study completes the important work published by Herbert Süss in 1958.  相似文献   

9.
In this article we describe the microscopic structures of a silicified piece of wood collected in the Middle Awash Valley (Ethiopia). The fossil wood was extracted from sediment precisely dated 4.4 Ma. Its attribution to the Ficoxylon species is based upon detailed comparison with published data and with comparisons of some modern species of the genus Ficus and similar characters encountered in fossil woods from West Africa, Egypt, Libya and Ethiopia previously described and attributed to this taxon.  相似文献   

10.
《Palaeoworld》2023,32(3):367-372
The afrosoricids are an endemic order exclusively from Africa with a very scarce fossil record. In this work, we present the first record outside this continent. The “otter shrew” Europotamogale melkarti n. gen. n. sp. was found in the Moreda 3 karstic fill site in Granada (Spain), of MN15 age (mid-Pliocene). This new taxon confirms the semiaquatic faunal interchange between Europe and Africa. We hypothesize that this tenrecid, representative of a family frequently present in the Central African faunas, migrated to the north of the continent via the Sahabi river system that connected North and Central Africa. Europotamogale n. gen. is the first known afrosoricid that migrated between the two continents. It was present in Europe for a very short time (as a ‘tourist genus’). To date, this phenomenon has only been described in genera of European origin, such as the pika Prolagus or the mouse Apodemus.  相似文献   

11.
The Late Cretaceous record of mammals from India assumes great significance in view of the fact that it is the only Gondwanan landmass that has yielded definitive eutherian mammals. These mammals have variously been assigned to palaeoryctids, archontans or Eutheria incertae sedis. Well preserved lower molars recovered from a new mammal-yielding Deccan intertrappean site near Kisalpuri village, Dindori District, Madhya Pradesh (state), India, are described here under a new species Deccanolestes narmadensis sp. nov. The new fossil material indicates close phylogenetic relationship between Deccanolestes from India and Afrodon (Adapisoriculidae) from the Late Palaeocene of Africa and Europe. In view of older age and more primitive state of Deccanolestes teeth, it is inferred that Deccanolestes represents an ancestral morphotype from which the African/European adapisoriculid Afrodon may have been derived. This is the first compelling terrestrial fossil evidence for an early dispersal between India and Africa. Such a dispersal possibly involved an East African contact with India at the KT transition.  相似文献   

12.
We document the presence of the bald ibis genus Geronticus Wagler, 1832 (Aves: Threskiornithidae) from the mid-Pliocene (ca. 3–3.5 Ma) of South Africa based on an incomplete skull from the Bolt’s Farm Cave System (Cradle of Humankind, Gauteng, South Africa). The fossil cranium is distinct on morphometric and structural grounds from Geronticus apelex, the only other Pliocene Geronticus described from Southern Africa, but is very close in dimensions and general morphology to the extant G. calvus of South Africa, and the Bolt’s Farm fossil ibis is therefore attributed to G. cf. calvus. Modern Geronticus ibises are localised to temperate, open grasslands and semi-arid steppe, and nest exclusively on cliffs and similar rocky eminences. Given its attribution as G. cf. calvus, the Bolt’s Farm ibis was likely similar in ecology to the extant G. calvus, suggesting that the habitat surrounding the Bolt’s Farm fossil site during the mid-Pliocene featured open grassland and presence of cliffs. This record constrains the divergence between G. calvus and its putative ancestor G. apelex to the mid-Pliocene and implies that G. calvus has possibly been subject to “evolutionary/morphological stasis” for more than 3 million years. This postulated stasis would be consistent with the notion that extant genera with few species (i.e. high genus-to-species ratios) show low rates of phenotypic diversification and change through the Neogene.  相似文献   

13.
14.
The skull of a subadult female of Simopithecus darti from the “Upper Phase I” of the Makapansgat Limeworks, South Africa, is described. It is the first complete skull of Simopithecus which is recorded from the lower Pleistocene “Australopithecine cave deposits” of southern Africa. The present skull shows an interesting mixture of primitive and advanced features. In some respects, it is reminiscent of Parapapio, in others it seems to have affinities with the extant Theropithecus gelada rather than with Simopithecus oswaldi. The systematics of the fossil genus Simopithecus and of the tribe Theropithecini Jolly (1966) are discussed.  相似文献   

15.
16.
The study of imprints of fossil plants collected in the Permian from the country of Hammanskraal (Namibia) leads to the following identifications: Glossopteris sp., Gangamopteris sp., Noegerrathiopsis sp., Gondwanidium sp., Asterotheca sp. and Lycopodiopsis derbyiB. Renault, Lycopodiopsis costilatus n. sp., Brasilodendron pedroanum(W. Carruthers) W.G. Chaloner & alii, Brasilodendron africanum n. sp. This flora has affinities with some fossil floras from South Africa and from Brazil, and is, probably, of upper Permian age.  相似文献   

17.
Recent humans and their fossil relatives are classified as having thick molar enamel, one of very few dental traits that distinguish hominins from living African apes. However, little is known about enamel thickness in the earliest members of the genus Homo, and recent studies of later Homo report considerable intra- and inter-specific variation. In order to assess taxonomic, geographic, and temporal trends in enamel thickness, we applied micro-computed tomographic imaging to 150 fossil Homo teeth spanning two million years. Early Homo postcanine teeth from Africa and Asia show highly variable average and relative enamel thickness (AET and RET) values. Three molars from South Africa exceed Homo AET and RET ranges, resembling the hyper thick Paranthropus condition. Most later Homo groups (archaic European and north African Homo, and fossil and recent Homo sapiens) possess absolutely and relatively thick enamel across the entire dentition. In contrast, Neanderthals show relatively thin enamel in their incisors, canines, premolars, and molars, although incisor AET values are similar to H. sapiens. Comparisons of recent and fossil H. sapiens reveal that dental size reduction has led to a disproportionate decrease in coronal dentine compared with enamel (although both are reduced), leading to relatively thicker enamel in recent humans. General characterizations of hominins as having ‘thick enamel’ thus oversimplify a surprisingly variable craniodental trait with limited taxonomic utility within a genus. Moreover, estimates of dental attrition rates employed in paleodemographic reconstruction may be biased when this variation is not considered. Additional research is necessary to reconstruct hominin dietary ecology since thick enamel is not a prerequisite for hard-object feeding, and it is present in most later Homo species despite advances in technology and food processing.  相似文献   

18.
The fossil cercopithecoid material from South Africa has been reviewed according to sites and species. The 722 specimens considered comprise 6 genera including 16 taxa and come from 16 sites. Aspects of taxonomic controversy and interest are discussed. In particular, the Parapapio material from Makapansgat has been re-evaluated and the taxonomy of the genus Simopithecus is reconsidered. A number of proposals are put forward. Four new specimens from Makapansgat and one from Sterkfontein are described; a previously partially described specimen from Taung is re-described in detail.  相似文献   

19.
Crocodylian remains are collected in 39 fossil-bearing localities but only in seven localities specimens with reliable taxonomic attributions, at least to genus level have been collected. Three species have been reported from the early Lutetian Purga di Bolca site: Pristichampsus cf. Pristichampsus rollinati, Asiatosuchus sp., Hassiacosuchus sp. (=Allognathosuchus sp.). The three crocodilians discovered at Purga di Bolca have been reported also from Geiseltal and Messel (Middle Eocene, Germany). Bolca at that time was part of a Tethysian archipelago and no mammals have been found there till now. Crocodilians and turtles clearly arrived from the European mainland across a marine water barrier. Among the other fossiliferous localities of Veneto, very interesting is the Monte Zuello site, of late Middle Eocene age, yielding a longirostrine crocodilian, Megadontosuchus arduini, a tomistomine species. Tomistomines are known in contemporaneous sediments of both Europe and Africa, but the European forms Dollosuchus and Kentisuchus seem the closest taxa. Remains of Oligocene age have been collected in Veneto and Liguria, but the fossils discovered in the second region are teeth or fragmented bones. The fossil crocodilians of Monteviale (Veneto), of Early Oligocene age, have been assigned to two species but they have been recently all identified as Diplocynodon ratelii, known from several European sites of Late Eocene, Oligocene and Miocene age. This species arrived in the Monteviale area from the European mainland across a narrow sea. Several crocodilian fossils of Miocene age are very fragmentary or represented by isolated teeth. In the Middle and Late Miocene of Sardinia, a well-established species, Tomistoma calaritanum is present. Remains of Tomistoma of the same age have been reported in some localities in Tuscany, Apulia, Sicily and Malta. In the Mediterranean area, the genus is known from European and African sites (of older age). The colonisation of Europe by this genus is the result of a dispersion from Africa (or less probably from Asia). During Late Miocene Sardinia and Tuscany belong to the same palaeobioprovince characterized by the Oreopithecus-Maremmia fauna. In Tuscany, a crocodilian identified as Crocodylus bambolii is present in the late Miocene site of Monte Bamboli. If the generic attribution of this form is correct, its ancestors must have arrived from Africa. Another fossil assemblage of Late Miocene age characterizes the Apulia-Abruzzi palaeobioprovince (Hoplitomeryx-Microtia fauna) and testifies complete isolation between the two palaeobioprovinces. In this last area, remains of Crocodylus sp. have been collected in coastal sandstones at Scontrone (Abruzzi) and in several fissure fillings of Gargano of slightly younger age. The ancestors of this species arrived from Africa while no African elements are present among the mammalian fauna. The dispersion of the genus Crocodylus in the Italian palaeoislands may have taken place once, with allopatric differentiation of the two populations (Tuscany-Sardinia and Apulia-Abruzzi) or twice with independent colonisation of each area.  相似文献   

20.
Two fossil taxa Tubulifloridites antipodica and T. viteauensis recovered from the Eocene Knysna Lignite of South Africa were examined with scanning (SEM) and transmission electron microscopy (TEM). The details of their sculpturing and wall structure are similar to the same species of fossil dispersed pollen taxa recovered from southwestern Africa and South America. Fifteen species of the woody South African taxa, Brachylaena (9 species) and Tarchonanthus (6 species) were investigated with SEM and TEM. All of the taxa are tricolporate, spherical to slightly prolate, microechinate to echinate and have a bilayered columellate infrastructure, except B.ilicifolia, which has a single columellate infrastructural level with the “granularization” of the outer portion of the infrastructural layer or the inner layer of the tectum. There is a similar distribution of plesiomorphic and derived pollen characters in a number of aster subfamilies and tribes suggesting a similar evolutionary progression of pollen, and pollen wall character evolution was occurring synchronously in a variety of aster subfamilies during the middle Tertiary and that these unique pollen features may be important to the evolution and diversification of the Asteraceae.  相似文献   

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