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1.
《Comptes Rendus Palevol》2016,15(7):791-812
The land mammal record of the Vallès-Penedès Basin (Catalonia, NE Spain) ranges from the early Miocene (Ramblian) to the late Miocene (Turolian), that is from about 20 to 7 Ma. Here we present an updated review of the mammal succession focusing on biochronology as well as on environmental and faunal changes. Based on faunal similarities with central Europe, we interpret this basin as a transitional zone between the forested environments of northern regions and the more arid landscapes of the inner Iberian Peninsula. The quality of the Vallès-Penedès record and its chronostratigraphic control is clearly better for the late Aragonian and the Vallesian (between 12.6–9.0 Ma), especially for small mammals. Therefore, we analyze small mammal diversity dynamics during this interval. Contrary to previous analyses, which found an abrupt extinction event coinciding with the early/late Vallesian boundary (the Vallesian Crisis), our results show that this pattern is due to uneven sampling. Instead, taxonomic richness slowly decreased since the late Vallesian as a result of a series of extinctions that mostly affected forest-dwelling taxa.  相似文献   

2.
The Late Miocene and Pliocene continental sediments in the Granada Basin (southern Spain) have yielded large amounts of fossil small mammals in 37 localities from 11 sections. The aim of this paper is to integrate faunistic, stratigraphic, and sedimentary criteria to unravel the geological history of the continental infilling of the basin. The palaeontological study has led to a detailed biozonation on the basis of rodents, which helps to correlate in detail the different sedimentary units found in the basin, and to follow the changes of the different sedimentary systems and their palaeogeographical evolution through time. Combination of the proposed biostratigraphy and the reinterpretation of the magnetostratigraphic analyses of the Barranco del Purcal section allows us to assign an absolute age slightly older than 5.23 Ma to the Turolian–Ruscinian boundary (MN13‐MN14).  相似文献   

3.
The late Miocene North African mammalianassemblage is considered here from three viewpoints: survivals, extinctions, and immigrations. The Eurasiatic affinities of the large mammals slightly prevail over the Ethiopian affinities. Amongst the North African large mammals, 4 to 8 taxa are Eurasiatic immigrants, while 4 to 6 are of Subsaharian origin. Contrarily, the micromammalian fauna is highly endemic, with only one species, a murid (Paraethomys miocaenicus), considered here as being related to an Asiatic form (Karnimata darwini). Our study of Eurasian and African Miocene faunas reveals that during the late Astaracian-early Turolian interval, the Saharo-Arabic belt permitted very little latitudinal faunal exchanges. However, during the middle and late Turolian such faunal exchanges became frequent. The micromammal record unequivocally indicates that a brief period of faunal exchange occurred between Africa and western Europe at the end of the Miocene, corresponding with the Messinian Salinity Crisis. The increased intercontinental faunal exchange between Africa and Eurasia during the late Miocene coincides with, and counterbalances the extinction of more than 10 taxa at the Mio/Pliocene boundary.  相似文献   

4.
Understanding recent biogeographic responses to climate change is fundamental for improving our predictions of likely future responses and guiding conservation planning at both local and global scales. Studies of observed biogeographic responses to 20th century climate change have principally examined effects related to ubiquitous increases in temperature – collectively termed a warming fingerprint. Although the importance of changes in other aspects of climate – particularly precipitation and water availability – is widely acknowledged from a theoretical standpoint and supported by paleontological evidence, we lack a practical understanding of how these changes interact with temperature to drive biogeographic responses. Further complicating matters, differences in life history and ecological attributes may lead species to respond differently to the same changes in climate. Here, we examine whether recent biogeographic patterns across California are consistent with a warming fingerprint. We describe how various components of climate have changed regionally in California during the 20th century and review empirical evidence of biogeographic responses to these changes, particularly elevational range shifts. Many responses to climate change do not appear to be consistent with a warming fingerprint, with downslope shifts in elevation being as common as upslope shifts across a number of taxa and many demographic and community responses being inconsistent with upslope shifts. We identify a number of potential direct and indirect mechanisms for these responses, including the influence of aspects of climate change other than temperature (e.g., the shifting seasonal balance of energy and water availability), differences in each taxon's sensitivity to climate change, trophic interactions, and land‐use change. Finally, we highlight the need to move beyond a warming fingerprint in studies of biogeographic responses by considering a more multifaceted view of climate, emphasizing local‐scale effects, and including a priori knowledge of relevant natural history for the taxa and regions under study.  相似文献   

5.
Chalicotheriids are rare in the late Miocene mammal localities of Axios Valley, Macedonia (Greece). The new campaign of excavations, since 1972, has provided some specimens, which are studied in this article. They are coming from two different localities. The late early Vallesian locality of Pentalophos 1 (PNT) has provided a skull and a mandible of an Ancylotherium. The morphological characters of the PNT material as the small size, the long snout, the shallow mandibular corpus, the strong cingulum in the teeth, the short tooth rows and the short M3/m3 indicate that it differs from the known Turolian species A. pentelicum and allow the erection of a new species, named Ancylotherium hellenicum n. sp., which can be used as a biostratigraphic marker of the Vallesian. The middle Turolian locality Prochoma 1 (PXM) has provided only one M3, which is determined to the chalicotheriine Anisodon macedonicus. This species was earlier described from the middle Turolian locality Vathylakkos 3 (VAT) and the late Turolian one of Dytiko 3 (DKO) of Axios Valley. The biogeography and biostratigraphy of the late Miocene chalicotheres of the Greco-Iranian Palaeoprovince (GRIP), as well as their palaeoecology are also discussed. The common chalicothere of GRIP is A. pentelicum, expanded from the Balkans to Afganistan and ranging stratigraphically from the early to the late Turolian. Chalicotherium goldfussi is certainly present in GRIP and it also ranges from the early to the late Turolian; its possible Vallesian occurrence needs confirmation. The other two late Miocene chalicotheres of GRIP A. macedonicus and Kalimantsia bulgarica are restricted to the Turolian of the Balkan Peninsula.  相似文献   

6.
Thick Cenozoic deposits in the Qaidam Basin provide great potential for understanding the tectonic history, paleoclimatic changes, and evolution of the East Asian Monsoon. This study examines the pollen record from the KC-1 core for the interval covering the later Early to Late Miocene (18–5 Ma). Thermophilic taxa percentages are high between 18 and 14 Ma and decrease after this time, a pattern which fits well with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and global climatic cooling after 14 Ma. During the same period, xerophytic taxa percentages gradually increase and those of the conifers gradually decrease, suggesting an aridification process in the Qaidam region driven by the gradual strengthening of the East Asian winter monsoon (EAWM) and weakening of the East Asian summer monsoon (EASM). The global climate cooling process appears to have driven the climatic development of the Qaidam Basin region throughout the Miocene, but the uplift of the Tibetan Plateau also contributed.  相似文献   

7.
Responses of grassland carbon (C) cycling to climate change and land use remain a major uncertainty in model prediction of future climate. To explore the impacts of global change on ecosystem C fluxes and the consequent changes in C storage, we have conducted a field experiment with warming (+3 °C), altered precipitation (doubled and halved), and annual clipping at the end of growing seasons in a mixed‐grass prairie in Oklahoma, USA, from 2009 to 2013. Results showed that although ecosystem respiration (ER) and gross primary production (GPP) negatively responded to warming, net ecosystem exchange of CO2 (NEE) did not significantly change under warming. Doubled precipitation stimulated and halved precipitation suppressed ER and GPP equivalently, with the net outcome being unchanged in NEE. These results indicate that warming and altered precipitation do not necessarily have profound impacts on ecosystem C storage. In addition, we found that clipping enhanced NEE due to a stronger positive response of GPP compared to ER, indicating that clipping could potentially be an effective land practice that could increase C storage. No significant interactions between warming, altered precipitation, and clipping were observed. Meanwhile, we found that belowground net primary production (BNPP) in general was sensitive to climate change and land use though no significant changes were found in NPP across treatments. Moreover, negative correlations of the ER/GPP ratio with soil temperature and moisture did not differ across treatments, highlighting the roles of abiotic factors in mediating ecosystem C fluxes in this grassland. Importantly, our results suggest that belowground C cycling (e.g., BNPP) could respond to climate change with no alterations in ecosystem C storage in the same period.  相似文献   

8.
In Western Europe, the change from the Middle Miocene forest-adapted mammalian faunas to the more open woodland faunas of the later Neogene, took place through an abrupt critical period known as the Vallesian Crisis. The Vallesian Crisis involved the disappearance of most of the forest-adapted elements characterizing the middle Miocene, such as tapirs, rhinoceroses, wet-adapted artiodactyls, hominoids, rodents, and the large carnivores of the families Nimravidae and Amphicyonidae. Detailed analysis in the well-calibrated and mostly complete sequence of the type area of the Vallesian Mammal stage, the Vallès-Penedès Basin (NE Spain), reveals that entries were always above the level of exits during the early Vallesian, reaching a diversity maximum at the end of this time. At 9.75 Ma, the Vallesian Crisis involved a sudden decrease of diversity, caused by high extinction levels, well above the number of entries. This event can be correlated with Mi7, a minor isotopic shift at about 9.6 Ma. The correlation of the Vallesian Crisis with such a minor isotopic shift is in contrast with previous, more significant isotopic shifts which had little ecological effects on the terrestrial ecosystems. This inconsistency between the global climate change inferred from the oceanic record and its effect on the structure of the late Miocene terrestrial ecosystems calls for some caution when inferring direct, linear relationships between climate change and mammalian turnover. In contrast with the Plio-Pleistocene glacial-interglacial dynamics, the effects of this climate forcing seem to have been more complex during Miocene times. An alternative pattern of change can be envisaged by proposing a “House of Cards” effect for the Vallesian Crisis. Increasing diversity levels after a prolonged period of stability enhanced terrestrial ecosystems to evolve into a self-organized critical state, which suddenly dropped after a critical threshold was surpassed. In contrast to other critical periods, the final decline of the Vallesian chronofauna was more dependent on the critical state of the system than on the magnitude of the agent which induced the crisis.  相似文献   

9.
Aim To analyse the fossil species assemblages of rodents and lagomorphs from the European Neogene in order to assess what factors control small mammal biogeography at a deep‐time evolutionary time‐scale. Location Western Europe: 626 fossil‐bearing localities located within 31 regions and distributed among 18 successive biochronological units ranging from c. 27 Ma (million years ago; Late Oligocene) to c. 3 Ma (mid Pliocene). Methods Taxonomically homogenized pooled regional assemblages are compared using the Raup and Crick index of faunal similarity; then, the inferred similarity matrices are visualized as neighbour‐joining trees and by projecting the statistically significant interregional similarities and dissimilarities onto palaeogeographical maps. The inferred biogeographical patterns are analysed and discussed in the light of known palaeogeographical and palaeoclimatic events. Results Successive time intervals with distinct biogeographical contexts are identified. Prior to c. 18 Ma (Late Oligocene and Early Miocene), a relative faunal homogeneity (high interregional connectivity) is observed all over Europe, a time when major geographical barriers and a weak climatic gradient are known. Then, from the beginning of the Middle Miocene onwards, the biogeography is marked by a significant decrease in interregional faunal affinities which matches a drastic global climatic degradation and leads, in the Late Miocene (c. 11 Ma), to a marked latitudinal pattern of small mammal distribution. In spite of a short rehomogenization around the Miocene/Pliocene boundary (6–4 Ma), the biogeography of small mammals in the mid Pliocene (c. 3 Ma) finally closely reflects the extant situation. Main conclusions The resulting biogeographical evolutionary scheme indicates that the extant endemic situation has deep historical roots corresponding to global tectonic and climatic events acting as primary drivers of long‐term changes. The correlation of biogeographical events with climatic changes emphasizes the prevalent role of the climate over geography in generating heterogeneous biogeographical patterns at the continental scale.  相似文献   

10.
Minwer‐Barakat, R., García‐Alix, A., Suárez, E.M., Freudenthal, M. & Viseras, C. 2012 xx xx: Micromammal biostratigraphy of the Upper Miocene to lowest Pleistocene continental deposits of the Guadix basin, southern Spain. Lethaia, Vol. 45, pp. 594–614. Recent study of the small mammals (rodents and insectivores) from several fossil‐bearing sites situated in the central sector of the Guadix Basin (Southern Spain) has notably increased the knowledge of the mammal assemblages that existed in Southern Iberia from the latest Miocene to the earliest Pleistocene. On the basis of this new information, we propose a biozonation for the continental deposits of the Guadix Basin, which consists of six biozones ranging in age from the late Turolian (MN13) to the early Villanyian (MN17). These biozones, defined according to the rules of the International Stratigraphical Guide, include not only the mentioned recently discovered fossil sites, but also other, previously known, localities of the basin. Finally, we integrate the described biozones in the Neogene Mammal units and the European Land Mammal Ages, correlate them with several classical mammal sites from other Iberian basins and the rest of Europe, and establish an approximate numerical age for the lower and upper limits of each biozone. □Biostratigraphy, Guadix Basin, rodents, insectivores, Upper Miocene, Pliocene, Pleistocene.  相似文献   

11.
We investigate resource and habitat use by apex predators through stable isotope analysis at two Spanish Late Miocene localities: Los Valles de Fuentidueña (~9.6 Ma, LVF) and Cerro de los Batallones (~9.1 Ma, BAT). The temporal window represented by LVF and BAT was crucial in the shaping of the current Iberian mammalian structure because it corresponds to the initial stages of a faunal turnover episode and regional environmental change at ~9.5–8.5 Ma (Vallesian–Turolian transition), associated with an increase in the seasonality of precipitation. Herbivore and carnivore δ13C and δ18O values do not point to significant changes in either the vegetation cover (a woodland to mesic C3 grassland) or the hydrological regime during the time lapse represented between LVF and BAT. This suggests that the environmental shift recorded around the Vallesian–Turolian boundary may have occurred later in time, since LVF and BAT ages are synchronic with the onset of the turnover event. From the standpoint of predator–prey evaluation by means of stable isotope analysis, statistical post hoc tests, mixing model output, and the assessment of niche occupation by LVF and BAT carnivores point to high levels of interspecific competition among large active carnivores, albeit some genera, such as the amphicyonid Magericyon and specially the hyaenid Lycyaena, seemed to avoid competition by taking prey from a more open habitat. Despite the drop in diversity and change in faunal components observed between the LVF and BAT assemblages, a high degree of resource and habitat competition is evident from stable isotope data.  相似文献   

12.
Tropical rain forest has been a persistent feature in South America for at least 55 million years. The future of the contemporary Amazon forest is uncertain, however, as the region is entering conditions with no past analogue, combining rapidly increasing air temperatures, high atmospheric carbon dioxide concentrations, possible extreme droughts, and extensive removal and modification by humans. Given the long‐term Cenozoic cooling trend, it is unknown whether Amazon forests can tolerate air temperature increases, with suggestions that lowland forests lack warm‐adapted taxa, leading to inevitable species losses. In response to this uncertainty, we posit a simple hypothesis: the older the age of a species prior to the Pleistocene, the warmer the climate it has previously survived, with Pliocene (2.6–5 Ma) and late‐Miocene (8–10 Ma) air temperature across Amazonia being similar to 2100 temperature projections under low and high carbon emission scenarios, respectively. Using comparative phylogeographic analyses, we show that 9 of 12 widespread Amazon tree species have Pliocene or earlier lineages (>2.6 Ma), with seven dating from the Miocene (>5.6 Ma) and three >8 Ma. The remarkably old age of these species suggest that Amazon forests passed through warmth similar to 2100 levels and that, in the absence of other major environmental changes, near‐term high temperature‐induced mass species extinction is unlikely.  相似文献   

13.
Abstract

The Neogene Fortuna Basin (Murcia Region, SE Spain) is rich in microvertebrate sites. Its continental sections include localities extended from the middle Turolian (MN12) to the early Ruscinian (MN14). However, there are few works dealing with the taxonomy of these fossil assemblages. In this paper we provide a complete taxonomic study of the rodents and insectivores from three levels (ROM-2B, ROM-2C and ROM-3A) within the Romerales section. We infer a late Turolian age (late Messinian) for these levels, among which the richest and most diverse level is ROM-C, including at least 11 different taxa. In addition, the paleoecological analysis of these fossil assemblages suggests the dominance of open herbaceous meadows under temperate climate during the formation of these sites, with a slight decrease in temperature and humidity from ROM-2B to ROM-2C.  相似文献   

14.
Climate warming has substantially advanced spring leaf flushing, but winter chilling and photoperiod co‐determine the leaf flushing process in ways that vary among species. As a result, the interspecific differences in spring phenology (IDSP) are expected to change with climate warming, which may, in turn, induce negative or positive ecological consequences. However, the temporal change of IDSP at large spatiotemporal scales remains unclear. In this study, we analyzed long‐term in‐situ observations (1951–2016) of six, coexisting temperate tree species from 305 sites across Central Europe and found that phenological ranking did not change when comparing the rapidly warming period 1984–2016 to the marginally warming period 1951–1983. However, the advance of leaf flushing was significantly larger in early‐flushing species EFS (6.7 ± 0.3 days) than in late‐flushing species LFS (5.9 ± 0.2 days) between the two periods, indicating extended IDSP. This IDSP extension could not be explained by differences in temperature sensitivity between EFS and LFS; however, climatic warming‐induced heat accumulation effects on leaf flushing, which were linked to a greater heat requirement and higher photoperiod sensitivity in LFS, drove the shifts in IDSP. Continued climate warming is expected to further extend IDSP across temperate trees, with associated implications for ecosystem function.  相似文献   

15.
Large proportions of the Earth's land surface are covered by biomes dominated by C(4) grasses. These C(4)-dominated biomes originated during the late Miocene, 3-8 million years ago (Ma), but there is evidence that C(4) grasses evolved some 20 Ma earlier during the early Miocene/Oligocene. Explanations for this lag between evolution and expansion invoke changes in atmospheric CO(2), seasonality of climate and fire. However, there is still no consensus about which of these factors triggered C(4) grassland expansion. We use a vegetation model, the adaptive dynamic global vegetation model (aDGVM), to test how CO(2), temperature, precipitation, fire and the tolerance of vegetation to fire influence C(4) grassland expansion. Simulations are forced with late Miocene climates generated with the Hadley Centre coupled ocean-atmosphere-vegetation general circulation model. We show that physiological differences between the C(3) and C(4) photosynthetic pathways cannot explain C(4) grass invasion into forests, but that fire is a crucial driver. Fire-promoting plant traits serve to expand the climate space in which C(4)-dominated biomes can persist. We propose that three mechanisms were involved in C(4) expansion: the physiological advantage of C(4) grasses under low atmospheric CO(2) allowed them to invade C(3) grasslands; fire allowed grasses to invade forests; and the evolution of fire-resistant savanna trees expanded the climate space that savannas can invade.  相似文献   

16.
17.
《Comptes Rendus Palevol》2002,1(2):117-122
Paracamelus cf. aguirrei from Çobanpinar (Turkey) is described. Rodents from that locality suggest a Late Turolian or Latest Miocene age, indicating that this is one of the oldest records of the genus. Paracamelus dispersed from North America in a relatively short period during the Late Turolian (MN13) into the extensive open and dry environments from central Asia to North Africa, as well as into southern Spain. To cite this article: J. van der Made et al., C. R. Palevol 1 (2002) 117–122.  相似文献   

18.
Landraces are local populations of crop plants adapted to a particular environment. Extant landraces are surviving genetic archives, keeping signatures of the selection processes experienced by them until settling in their current niches. This study intends to establish relationships between genetic diversity of barley (Hordeum vulgare L.) landraces collected in Spain and the climate of their collection sites. A high‐resolution climatic data set (5 × 5 km spatial, 1‐day temporal grid) was computed from over 2,000 temperature and 7,000 precipitation stations across peninsular Spain. This data set, spanning the period 1981–2010, was used to derive agroclimatic variables meaningful for cereal production at the collection sites of 135 barley landraces. Variables summarize temperature, precipitation, evapotranspiration, potential vernalization and frost probability at different times of the year and time scales (season and month). SNP genotyping of the landraces was carried out combining Illumina Infinium assays and genotyping‐by‐sequencing, yielding 9,920 biallelic markers (7,479 with position on the barley reference genome). The association of these SNPs with agroclimatic variables was analysed at two levels of genetic diversity, with and without taking into account population structure. The whole data sets and analysis pipelines are documented and available at https://eead-csic-compbio.github.io/barley-agroclimatic-association . We found differential adaptation of the germplasm groups identified to be dominated by reactions to cold temperature and late‐season frost occurrence, as well as to water availability. Several significant associations pointing at specific adaptations to agroclimatic features related to temperature and water availability were observed, and candidate genes underlying some of the main regions are proposed.  相似文献   

19.
Mountains are among the most powerful natural gradients for testing ecological and evolutionary responses of biota to environmental influences because differences in climate and plant structure occur over short spatial scales. We describe the spatiotemporal distribution patterns and drives of fruit‐feeding butterfly diversity in the mountainous region of Serra do Cipó, Minas Gerais, Brazil. Seven elevations from 822 to 1,388 m a.s.l. were selected for evaluating the effects of abiotic factors and vegetation characteristics on butterfly diversity. A total of 44 fruit‐feeding butterfly species were recorded in a two‐year study. Species richness (local and regional) of fruit‐feeding butterflies decreased with increasing elevation. The interaction between temperature or humidity and precipitation influenced the abundance and β‐diversity of butterflies in the elevation gradient, whereas β‐diversity decreased with increasing plant richness. Butterfly richness (local and regional) and β‐diversity varied with the sampling period, with fewer species in July (2012 and 2013), the dry period, as expected for Neotropical insects. β‐Diversity in space and time was due to species replacement (turnover), indicating that butterfly composition differs throughout the mountain and over time. In summary, climate and plant richness largely influence butterfly diversity in the elevational gradient. Climatic changes in conjunction with increasing anthropic impacts on mountainous regions of southeast Brazil will likely influence the community of mountaintop butterflies in the Espinhaço Mountain Range. Abstract in Portuguese is available with online material.  相似文献   

20.
Caves may offer suitable refugia for troglophilic invertebrates during periods of unfavourable climatic conditions because of their stable microclimates. As a consequence, allopatric divergence from their epigean counterparts may occur, leading to formation of truly hypogean communities (the Climatic Relict Hypothesis). Unlike the well‐studied effects of Pleistocene glaciations, we know little about how ancient climate changes drove the development of cave‐dwelling organisms living at both middle and lower latitudes. We investigate the evolutionary history of the troglophilic spider genus Nesticella (Araneae, Nesticidae) in relation to Asian Neogene (23–2.6 Ma) climatic changes. Our analyses discern clear differences in the evolution of the two main clades of Nesticella, which occur in temperate/subtropical and tropical latitudes. Eastern Asian Nesticella gradually evolved greater sedentariness and a strict subterranean lifestyle starting from the middle Miocene Epoch (~15–14 Ma) in conjunction with the progressive deterioration of the climate and vegetational shifts. Caves appear to have acted as refugia because of their internally uniform temperature and humidity, which allowed these spiders to survive increasing external seasonality and habitat loss. In contrast, a uniform accumulation of lineages, long‐lasting times for dispersals and the lack of a comparable habitat shifting characterized the tropical lineage. This difference in pattern likely owes to the mild effects of climate change at low latitudes and the consequent lack of strong climatic drivers in tropical environments. Thus, the mid‐Miocene climatic shift appears to be the major evolutionary force shaping the ecological differences between Asian troglophilic invertebrates and the driver of the permanent hypogean communities in middle latitudes.  相似文献   

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