Faunal turnover rates and mammalian biodiversity of the late Pliocene and Pleistocene of eastern Africa

Paleobiology ◽  
2001 ◽  
Vol 27 (3) ◽  
pp. 500-511 ◽  
Author(s):  
Jeffrey K. McKee
Keyword(s):  
East Africa ◽  
Fossil Record ◽  
Empirical Support ◽  
Eastern Africa ◽  
Large Mammals ◽  
Turnover Rates ◽  
Late Pliocene ◽  
Faunal Turnover ◽  
Primary Basis ◽  
Fossil Data

Two models of faunal turnover patterns, one with constant turnover and another with climatically induced turnover pulses, were tested against the empirical fossil data of first and last appearances of large mammals from the late Pliocene and Pleistocene of East Africa. Computer simulations of each model were generated by first creating change in hypothetical faunal communities and then sampling the evolving communities in a manner scaled to the specific contingencies of the East African fossil record. Predictions of the two turnover models were compared with the empirical data. Neither model yielded predictions that deviated significantly from the observed patterns of first and last appearances of species, and both models produced extremely similar results. The implication is that the fossil data of East Africa are not refined enough to detect variations in the pace of turnover; the patterns of first- and last-appearance frequencies are determined more by the contingencies of the fossil record than by the underlying evolutionary and migrational patterns. Whereas these results undermine the primary basis of empirical support for the turnover-pulse hypothesis, they do not imply that other models are more likely. However, the simulation results were highly suggestive of significant reduction in species biodiversity of large mammals during the past 2 Myr.

scholarly journals Continuous evolutionary change in Plio-Pleistocene mammals of eastern Africa

2015 ◽  
Vol 112 (34) ◽  
pp. 10623-10628 ◽  
Author(s):  
Faysal Bibi ◽  
Wolfgang Kiessling
Keyword(s):  
Fossil Record ◽  
Global Climate ◽  
Biotic Interactions ◽  
Eastern Africa ◽  
Faunal Turnover ◽  
Occupancy Patterns ◽  
Ecological Changes ◽  
African Mammals ◽  
Basin Scale ◽  
Pleistocene Mammals

Much debate has revolved around the question of whether the mode of evolutionary and ecological turnover in the fossil record of African mammals was continuous or pulsed, and the degree to which faunal turnover tracked changes in global climate. Here, we assembled and analyzed large specimen databases of the fossil record of eastern African Bovidae (antelopes) and Turkana Basin large mammals. Our results indicate that speciation and extinction proceeded continuously throughout the Pliocene and Pleistocene, as did increases in the relative abundance of arid-adapted bovids, and in bovid body mass. Species durations were similar among clades with different ecological attributes. Occupancy patterns were unimodal, with long and nearly symmetrical origination and extinction phases. A single origination pulse may be present at 2.0–1.75 Ma, but besides this, there is no evidence that evolutionary or ecological changes in the eastern African record tracked rapid, 100,000-y-scale changes in global climate. Rather, eastern African large mammal evolution tracked global or regional climatic trends at long (million year) time scales, while local, basin-scale changes (e.g., tectonic or hydrographic) and biotic interactions ruled at shorter timescales.

Diversification and extinction patterns among Neogene perimediterranean mammals

1989 ◽  
Vol 325 (1228) ◽  
pp. 401-420 ◽  
Keyword(s):  
Late Miocene ◽  
Fossil Record ◽  
Driving Forces ◽  
High Rate ◽  
Eastern Africa ◽  
European Continent ◽  
Southern France ◽  
Early Pliocene ◽  
Faunal Turnover ◽  
Extinction Event

The best mammalian fossil record during the Neogene of Western Europe is that of the rodents, the most successful and diversified mammal order. The study of origination and extinction during the Neogene (24-3 Ma BP) in one of the best documented areas, Spain and southern France, gives an insight into the dynamics of these communities and indicates the possible nature of the driving forces. Three main periods of time show a high rate of origination: the late Burdigalian (17.5 Ma BP), the early Vallesian (11.5-11 Ma BP) and the early Pliocene (4.2- 3.8 Ma BP). Two of these high origination-rate periods are immediately followed by important extinction events during which all cohorts are deeply affected (11.5-11 Ma BP and 4.2- 3.8 Ma BP). The most important extinction event seems to occur during the early Vallesian (11.5-11 Ma BP), which probably includes the middle/late Miocene boundary. At the Miocene/Pliocene boundary, and during the early Pliocene, the faunal turnover seems to become faster, inducing a strong decrease of the mean species duration. Whereas the main immigration event, which occurs at 17.5 Ma BP, can be related to other faunal migrations in terms of the closure of the Tethys, as it occurs also in eastern Africa and in southwest Asia, the middle/late Miocene boundary event may have been related to a period of ice growth in the Southern Hemisphere. The extinction event that affects the planktonic foraminifera at 12 Ma BP cannot be chronologically correlated to this southwestern European land-mammal extinction event, because the calibration of the marine fossil record during that time-span has to be precise. Some limited terrestrial faunal exchanges that occur during the Messinian between southwestern Europe and northwestern Africa do not deeply affect the general faunal dynamics. Both allochthonous cohorts of immigrants become rapidly extinct. Several endemic rodent faunas, indicating insular conditions, have been reported from the southern edge of the western European continent from the middle Miocene up to the Pliocene. All show low taxonomic diversity, strong endemism and short survival. Some of them, like those of the Gargano Islands during the late Miocene, underwent peculiar morphological changes and also speciation. The large number of rodent genera coevolving in the Gargano Islands is indicative of the large surface areas of these islands. The general geographic pattern of southwestern Europe during the Neogene may therefore correspond to a large continental province including Spain and southern France with some kind of fast-modifying archipelago on its southern rim.

A new species of Hippopotamidae (Mammalia, Artiodactyla) from the Sagantole Formation, Middle Awash, Ethiopia

2004 ◽  
Vol 175 (5) ◽  
pp. 525-533 ◽  
Author(s):  
Jean-Renaud Boisserie
Keyword(s):  
New Species ◽  
East Africa ◽  
Fossil Record ◽  
General Morphology ◽  
Middle Awash ◽  
A New Species

Abstract A new species of Hippopotamidae, Hexaprotodon dulu nov. sp., was discovered in the Middle Awash valley, Afar, Ethiopia. It was found in the Sagantole Formation, within volcaniclastic beds aged between 5.2 Ma and 4.9 Ma (40Ar/39Ar). It is therefore the oldest hippo species described as yet from Ethiopia. This hexaprotodont hippo exhibits a general morphology that is primitive, close in that respect to other Mio-Pliocene forms. However, its cranium and dentition display a distinctive association of measurements and features. This new species increases the hippo fossil record in East Africa. It also reinforces the hypothesis of hippo endemism in each African basin as early as the basal Pliocene.

scholarly journals Fossil biogeography: a new model to infer dispersal, extinction and sampling from palaeontological data

2016 ◽  
Vol 371 (1691) ◽  
pp. 20150225 ◽  
Author(s):  
Daniele Silvestro ◽  
Alexander Zizka ◽  
Christine D. Bacon ◽  
Borja Cascales-Miñana ◽  
Nicolas Salamin ◽  
...  
Keyword(s):  
North America ◽  
Fossil Record ◽  
Phylogenetic Trees ◽  
Phylogenetic Analyses ◽  
Historical Biogeography ◽  
Extinction Rates ◽  
Climatic Cooling ◽  
Fossil Data ◽  
Incomplete Sampling ◽  
Des Model

Methods in historical biogeography have revolutionized our ability to infer the evolution of ancestral geographical ranges from phylogenies of extant taxa, the rates of dispersals, and biotic connectivity among areas. However, extant taxa are likely to provide limited and potentially biased information about past biogeographic processes, due to extinction, asymmetrical dispersals and variable connectivity among areas. Fossil data hold considerable information about past distribution of lineages, but suffer from largely incomplete sampling. Here we present a new dispersal–extinction–sampling (DES) model, which estimates biogeographic parameters using fossil occurrences instead of phylogenetic trees. The model estimates dispersal and extinction rates while explicitly accounting for the incompleteness of the fossil record. Rates can vary between areas and through time, thus providing the opportunity to assess complex scenarios of biogeographic evolution. We implement the DES model in a Bayesian framework and demonstrate through simulations that it can accurately infer all the relevant parameters. We demonstrate the use of our model by analysing the Cenozoic fossil record of land plants and inferring dispersal and extinction rates across Eurasia and North America. Our results show that biogeographic range evolution is not a time-homogeneous process, as assumed in most phylogenetic analyses, but varies through time and between areas. In our empirical assessment, this is shown by the striking predominance of plant dispersals from Eurasia into North America during the Eocene climatic cooling, followed by a shift in the opposite direction, and finally, a balance in biotic interchange since the middle Miocene. We conclude by discussing the potential of fossil-based analyses to test biogeographic hypotheses and improve phylogenetic methods in historical biogeography.

scholarly journals More Than Names: The role of updated taxonomy in palaeontology collections

2019 ◽  
Vol 3 ◽  
Author(s):  
Ricardo Paredes
Keyword(s):  
Fossil Record ◽  
Marine Invertebrate ◽  
Research Community ◽  
Type Material ◽  
Museum Collections ◽  
Web Based ◽  
2D Imaging ◽  
Visual Impact ◽  
Fossil Data

The accuracy on taxonomic determinations of palaeontology collections may have significant consequences in estimations of organism diversity through time. This justifies the need of taxonomic standardization of palaeontological collections. The perception of palaeodiversity through Phanerozoic time has significantly improved since the Sepkoski showed the marine invertebrate taxonomic data in diversity graphs, organized in orders (Sepkoski 1978) and families (Sepkoski 1979, Sepkoski 1984). The visual impact of these graphs engaged palaeontologists into gathering quantitative macroevolution in order to better understand marine palaeodiversity. Alroy et al. (2008) presented a rebuilt diversity curve based on genus-level in a large sample record. These and other statistically sound and standardized datasets of fossil occurrences have combined sources as literature, databases, and museum collections data as a foundation. Integration of these datasets with the entire fossil record based on individual specimens in space and time would be the ideal approach to species-level taxonomy standards determinations. An example showing how this approach may be achieved is the use of initiatives such as the Web-based data facility Palaeontology Database (PdB) which includes a large amount of fossil record data from throughout the world. The major advantage of that is to gather institucional and also private palaeontological collections with taxonomy experts validation. The core of these datasets is the taxon, with the species as the expected most reliable unit. Taxonomy is therefore the discipline enrolled in the process with the taxonomist at the centre of the process. Updated taxonomy is crucial to create reliable datasets and a careful approach should prevent biased data due to under- or overestimation of diversity. Palaeontological museum collections are known to be one of the largest repositories of fossil data. Taxonomic standardization of palaeontology collections in the context of a museum should: Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. These practices are valuable complements to current methodologies adopted to improve the taxonomy of collections, resulting in more reliable data which further enables museum-based research focusing on palaeodiversity estimations.

scholarly journals A preliminary assessment of protected area management within the WWF ‘Coastal East Africa’ priority place, Eastern Africa

PARKS ◽  
2014 ◽  
Vol 20 (2) ◽  
pp. 77-88 ◽  
Author(s):  
Kathryn Knights ◽  
Ivon Cuadros ◽  
Camilo Zamora ◽  
Lauren Coad ◽  
Fiona Leverington ◽  
...  
Keyword(s):  
East Africa ◽  
Protected Area ◽  
Protected Area Management ◽  
Eastern Africa ◽  
Preliminary Assessment ◽  
Area Management

scholarly journals Prevalence of pneumonia and its associated factors among under five children in East Africa. Meta-analysis and systemic review

2020 ◽  
Author(s):  
Biruk Beletew Abate ◽  
Melaku Getahun Bimrew ◽  
Ayelign Mengesha Kasie ◽  
Mesfin Kassaw Wudu ◽  
Molla Azmeraw
Keyword(s):  
East Africa ◽  
Associated Factors ◽  
Meta Analysis ◽  
Eastern Africa ◽  
Systemic Review ◽  
Cochrane Library ◽  
Under Five ◽  
Under Five Children ◽  
The Impact ◽  
National Prevalence

Abstract Introduction Pneumonia is defined as an acute inflammation of the Lungs’ parenchymal structure. It is a major public health problem and the leading cause of morbidity and mortality in under-five children especially in developing countries. In 2015, it was estimated that about 102 million cases of pneumonia occurred in under-five children, of which 0.7 million were end up with death. Different primary studies in Eastern Africa showed the burden of pneumonia. However, inconsistency among those studies was seen and no review has been conducted to report the amalgamated magnitude and associated factors. Therefore, this review aimed to estimate the national prevalence and associated factors of neonatal sepsis in Eastern Africa. Objective The aim of this systematic review and meta-analysis was to assess the magnitude of pneumonia and its associated factors among under-five children in East Africa. Methods Using PRISMA guideline, we systematically reviewed and meta-analyzed studies that examined the prevalence and associated factors of pneumonia from PubMed, Cochrane library, and Google Scholar. Heterogeneity across the studies was evaluated using the Q and the I 2 test. A weighted inverse variance random-effects model was applied to estimate the national prevalence and the effect size of associated factors. The subgroup analysis was conducted by country, study design, and year of publication. A funnel plot and Egger’s regression test were used to see publication bias. Sensitivity analysis was also done to identify the impact of studies. Result A total of 34 studies with 87, 984 participants were used for analysis. The pooled prevalence of hypothermia in East Africa was 34% (95%CI; 23.80–44.21). Use of wood as fuel source (AOR= 1.53; 95%CI:1.30-1.77; I 2 = 0.0% ;P=0.465), cook food in living room (AOR= 1.47;95%CI:1.16-1.79; I 2 = 0.0% ;P=0.58), caring of a child on mother during cooking (AOR= 3.26; 95%CI:1.80-4.72; I 2 = 22.5% ;P=0.26), Being unvaccinated (AOR= 2.41; 95%CI:2.00-2.81; I 2 = 51.4% ;P=0.055), Child history of ARTI(AOR= 2.62; 95%CI:1.68-3.56; I 2 = 11.7% ;P=0.337) were identified factors of pneumonia. Conclusions The prevalence of pneumonia in Eastern Africa remains high. This review will help policy-makers and program officers to design pneumonia preventive interventions.

First study of the bat fossil record of the mid-Atlantic volcanic islands

2021 ◽  
pp. 1-15
Author(s):  
Javier GONZÁLEZ-DIONIS ◽  
Carolina CASTILLO RUIZ ◽  
Penélope CRUZADO-CABALLERO ◽  
Elena CADAVID-MELERO ◽  
Vicente D. CRESPO
Keyword(s):  
Atlantic Ocean ◽  
Iberian Peninsula ◽  
Central Europe ◽  
Canary Islands ◽  
Fossil Record ◽  
Dental Morphology ◽  
Lava Tubes ◽  
El Hierro ◽  
Volcanic Islands ◽  
Fossil Data

ABSTRACT Bats are one of the most abundant and important mammals in ecosystems. However, their fossil record is scarce and fragile, making them difficult to find. Accordingly, there is no record of this group in the volcanic islands of the mid-Atlantic Ocean apart from the Canary Islands. This paper studies the first bat fossil record of the Canary Islands (Spain). The material studied is found within two Quaternary lava tubes, Cueva de los Verdes on Lanzarote and Cueva Roja on the island of El Hierro. The dental and humeral morphology and biometry are analysed and compared with current specimens. Among our results we highlight the first fossil data of two species endemic to the islands of the mid-Atlantic Ocean, Plecotus teneriffae and Pipistrellus maderensis, the former from the Canary Islands and the latter from the Azores, Madeira and the Canary Islands. We also confirm the presence of Pipistrellus kuhlii in the fossil record of the island of Lanzarote. No differences are observed between the dental morphology of the current and the fossil populations of P. maderensis and Pl. teneriffae. In the case of P. kuhlii, the populations of the Canary Islands and the Iberian Peninsula show differences in the paraconule with respect to the populations from central Europe. Palaeoecological studies of these taxa suggest that these islands presented a similar habitat when the sites were formed to the present-day habitat.

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