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New Remains of Camelus grattardi (Mammalia, Camelidae) from the Plio-Pleistocene of Ethiopia and the Phylogeny of the Genus

International audienceThe Old World fossil record of the family Camelidae is patchy, but a new partial cranium and some other remains of Camelus grattardi from the Mille-Logya Project area in the Afar, Ethiopia, greatly increase the fossil record of the genus in Africa. These new data – together with analysis of unpublished and recently published material from other sites, and reappraisal of poorly known taxa – allow for a comprehensive phylogenetic analysis showing that C. grattardi is the earliest (2.2–2.9 Ma) and most basal species of the genus. We also show that the lineages leading to the extant taxa C. dromedarius and C. bactrianus diverged much higher in the tree, suggesting a recent age for this divergence. A late divergence date between the extant species is consistent with the absence of any fossil forms that could be ancestral, or closely related, to any of the extant forms before the late Pleistocene, but stands in contrast to molecular estimates which place the divergence between the dromedary and the Bactrian camel between 8 and 4 million years ago

Faunal turnover at Mille-Logya (Plio-Pleistocene, Ethiopia) reflects in situ environmental change: implications for the origins of Homo

The lower Awash Valley of Ethiopia preserves a significant record of Australopithecus afarensis at Hadar and Dikika in addition to the earliest fossil yet attributed to Homo from Ledi-Geraru at 2.8 Ma. However, understanding the context of the extinction of A. afarensis and the origin of Homo is hampered by the limited preservation of sediments between 2.9 – 2.3 Ma in the region. The Mille-Logya Project (MLP) preserves fossiliferous sediments post-dating 2.9 Ma. Here we present a quantitative analysis of the MLP mammalian fauna and explore implications of MLP faunal change for the origin of Homo.info:eu-repo/semantics/publishedVersio

Episodic outbreaks of small mammals infl uence predator community dynamics in an east African savanna ecosystem

Little is known about the dynamics of small mammals in tropical savanna: a critical gap in our understanding of Africa's best known ecosystems. Historical evidence suggested small mammals peak in abundance (outbreak) in Serengeti National Park (SNP), as in agricultural systems. We asked 1) what are bottom–up drivers of small mammals and 2) do predators have top–down effects? We documented dynamics of small mammals, birds of prey, and mammalian carnivores in SNP and agricultural areas. We used climatic fluctuations and differences between unmodified and agricultural systems as perturbations to examine trophic processes, key to understanding responses to climate change and increasing human pressures. Data were derived from intermittent measures of abundance collected 1968–1999, combined with systematic sampling 2000–2010 to construct a 42-year time series. Data on abundance of black-shouldered kites (1968–2010), eight other species of rodent-eating birds (1997–2010), and 10 carnivore species (1993–2010) were also collated. Outbreaks occurred every 3–5 years in SNP, with low or zero abundance between peaks. There was a positive relationship between rainfall in the wet season and 1) small mammal abundance and 2) the probability of an outbreak, both of which increased with negative Southern Oscillation Index values. Rodent-eating birds and carnivores peaked 6–12 months after small mammals. In agricultural areas, abundance remained higher than in natural habitats. Abundances of birds of prey and mammalian carnivores were extremely low in these areas and not related to small mammal abundance. Small mammals are an important food resource for higher trophic levels in the Serengeti ecosystem. Changes in climate and land use may alter their future dynamics, with cascading consequences for higher trophic levels, including threatened carnivores. Although outbreaks cause substantial damage to crops in agricultural areas, small mammals also play a vital role in maintaining some of the diversity and complexity found in African savanna ecosystems

A solution to the challenges of interdisciplinary aggregation and use of specimen-level trait data.

Understanding variation of traits within and among species through time and across space is central to many questions in biology. Many resources assemble species-level trait data, but the data and metadata underlying those trait measurements are often not reported. Here, we introduce FuTRES (Functional Trait Resource for Environmental Studies; pronounced few-tress), an online datastore and community resource for individual-level trait reporting that utilizes a semantic framework. FuTRES already stores millions of trait measurements for paleobiological, zooarchaeological, and modern specimens, with a current focus on mammals. We compare dynamically derived extant mammal species' body size measurements in FuTRES with summary values from other compilations, highlighting potential issues with simply reporting a single mean estimate. We then show that individual-level data improve estimates of body mass-including uncertainty-for zooarchaeological specimens. FuTRES facilitates trait data integration and discoverability, accelerating new research agendas, especially scaling from intra- to interspecific trait variability