Magnetostratigraphic dating of the Linyi Fauna and implications for sequencing the mammalian faunas on the Chinese Loess Plateau

The Chinese Loess Plateau (CLP) in North China is an important terrestrial archive that witnessed the environmental changes and mammal and early human evolution in Asia over the past 2.6 Ma. Establishing precise ages for the Pleistocene faunas on the CLP is critical for better understanding of these environmental, biological, and archaeological issues. Here we report a new magnetostratigraphic record that places age constraints on the Linyi Fauna on the southeastern CLP. Our investigated 170-m-thick Linyi section mainly consists of two portions: (1) an overlying eolian Quaternary loess-paleosol sequence and (2) underlying fluvial-lacustrine sand and silty clay. Paleomagnetic results suggest that the composite section records the Brunhes chron, Jaramillo and Olduvai subchrons, and successive reverse polarity portions of the intervening Matuyama chron. The Linyi Fauna is located between Jaramillo and Olduvai subchrons in the fluvial-lacustrine interval, with an estimated age of similar to 1.5-1.6 Ma. Combining previously dated faunas, we establish a Pleistocene magnetochronology spanning from 2.54 to 0.65 Ma for the faunas on the CLP

Self-grooming

Self-grooming in each experimental group

Data from: Flight is the key to postprandial blood glucose balance in the fruit bats Eonycteris spelaea and Cynopterus sphinx

1. Excessive sugar consumption could lead to high blood glucose levels that are harmful to mammalian health and life. 2. Despite consuming large amounts of sugar-rich food, fruit bats have a longer lifespan, raising the question of how these bats overcome potential hyperglycemia. 3. We investigated the change of blood glucose level in nectar-feeding bats (Eonycteris spelaea) and fruit-eating bats (Cynopterus sphinx) via adjusting their sugar intake and time of flight. 4. We found that the maximum blood glucose level of C. sphinx was higher than 24 mmol L-1 that is considered to be pathological in other mammals. After C. sphinx bats spent approximately 75 percent of their time to fly, their blood glucose levels dropped markedly, and the blood glucose of E. spelaea fell to the fast levels after they spent 70 percent time of fly. Thus, the level of blood glucose elevated with the quantity of sugar intake but declined with the time of flight. 5. Our results indicate that high-intensive flight is a key regulator for blood glucose homeostasis during foraging. High-intensive flight may confer benefits to the fruit bats in foraging success and behavioural interactions and increases the efficiency of pollen and seed disposal mediated by bats

New magnetochronology of Late Miocene mammal fauna, NE Tibetan Plateau, China : Mammal migration and paleoenvironments

Lanzhou Basin lies on the northeastern margin of the Tibetan Plateau in western China and is a rich source of Oligocene-Miocene mammalian fossils. Obtaining precise age determinations for these fossils is important to address key questions concerning mammalian and environmental evolution in Asia associated with stepwise Tibetan Plateau uplift. Here we report a new magnetostratigraphic record for the Xingjiawan fluvio-lacustrine section from the northwestern margin of Lanzhou Basin that can be correlated to the geomagnetic polarity timescale with two options. The Late Miocene Xingjiawan Fauna is located either at the boundary between reversed polarity chron C4r.1r and normal polarity chron C4n.2n or at the boundary between subchrons C5r.1r and C5n.2n, with an estimated age of at least ~8 Ma or perhaps as early as ~11 Ma. Both age estimations imply that the fossil Stegodon in the Lanzhou Basin is the oldest known record of Stegodon worldwide; it predates the formerly oldest Stegodon find from Africa by at least one million years and perhaps by as many as four million years. This provides new evidence for an Asian origin of Stegodon. Together with other faunal components, a mixed woodland/grassland setting existed in the Lanzhou Basin during the Late Miocene, in contrast to its modern arid environment

Early Pleistocene occurrence of Acheulian technology in North China

Acheulian tools with their associated level of cognizance heralded a major threshold in the evolution of hominin technology, culture and behavior. Thus, unraveling occurrence ages of Acheulian technology across different regions worldwide constitutes a key aspect of understanding the archeology of early human evolution. Here we present a magneto-cyclochronology for the Acheulian assemblage from Sanmenxia Basin, Loess Plateau, North China. Our results place a sequence of stable normal and reversed paleomagnetic polarities within a regional lithostratigraphic context. The Acheulian assemblage is dated to be older than the Matuyama–Brunhes boundary at 0.78 Ma, and is found in strata that are probably equivalent to a weak paleosol subunit within loess layer L9 in the Chinese loess-paleosol sequence, which corresponds to marine isotope stage (MIS) 23, a relatively subdued interglacial period with age range of ∼0.89–0.92 Ma. This age of ∼0.9 Ma implies that Acheulian stone tools were unambiguously present in North China during the Early Pleistocene. It distinctly enlarges the geographic distribution of Acheulian technology and brings its occurrence in North China back into the Early Pleistocene, which is contemporaneous with its first emergence in Europe. Combined with other archeological records, the larger area over which Acheulian technology existed in East Asia during the terminal Early Pleistocene has important implications for understanding early human occupation of North ChinaThis study was supported financially by Chinese Academy of Sciences (Youth Innovation Promotion Program and Key Research Program of Frontier Sciences), the National Natural Science Foundation of China (Grants 41420104008, 41174057, 41290250 and 41290253), the Australian Research Council (DP110105419), the International Partnership Program of Chinese Academy of Sciences (Grants 132B61KYSB20130003 and 132B61KYSB20160003), and the State Key Laboratory of Loess and Quaternary Geology at the Institute of Earth Environment, CAS (SKLLQG 1501 and 1502)

Similar adaptative mechanism but divergent demographic history of four sympatric desert rodents in Eurasian inland

Genome assembles for Northern three-toed jerboa, Siberian jerboa, Midday jird and Desert hamster and provides insights into similarities and differences in mechanisms for desert adaptation