A photo showing researchers collecting fossilized mammal teeth
June 10, 2010
A photo showing researchers collecting fossilized mammal teeth from a sandstone layer in the Gyirong Basin in the Himalayas for isotopic analyses to study the diets and environment of these ancient mammals. Although the area is a desert today, a study funded by grants from the National Science Foundation (INT 02-04923 and EAR 04-44073) found evidence indicating that the area had a very different climate and was at a much lower elevation about 7 million years ago. [One of seven related images. See Next Image.] [Date of Image: Summer 2004] More about this Image The purpose of the study, which was led by Dr. Yang Wang of Florida State University and professor Deng Tao of the Institute of Vertebrate Paleontology and Paleoanthropology, CAS, China, was to survey Cenozoic fossils in the northern Tibetan Plateau. Due to difficulties of access and extreme environments, the vast plateau is little explored and remains the last frontier for paleontological explorations. Preliminary surveys in the Qaidam basin, the largest terrestrial basin in the Tibetan Plateau, yielded a number of richly fossil-bearing localities ranging from early Miocene (about 24 to 16 million years ago) to Pliocene (about 5 to 2 million years ago). A team of paleontologists, structural and sedimentary geologists, isotope geochemists and paleomagnetists are systematically collecting fossilized mammals, fish and plants in the Qaidam basin and studying their paleoenvironments. Combined with paleomagnetic studies, the fossils help to establish the age of the rocks in which they were preserved. Sedimentologic studies on the river, lake and over-bank deposits also provide further evidence about the source of the sediments from the surrounding mountains; the nature of the paleodrainages; and the evolution of the basin history. Analyses of carbon and oxygen isotopes preserved in fossil mammalian teeth provide valuable information about the animal's diet (ex., was it a leaf browser or grass grazer?), environment (ex., did it live in the forest, or on grassland or in wooded grassland) and regional climate. Scientists hope to better understand the link between the uplift of the Tibetan Plateau and the late Cenozoic environmental and biotic changes by integrating the paleontologic, magnetic, sedimentary and geochemical data. Comparing fauna from the southern slope of Tibet in India and Pakistan with the Qaidam fauna to the north will offer clues of mammalian migrations and geographic barriers as the high Tibet continued to rise. The new data are particularly relevant in the current debate over the impact of the rising Tibetan Plateau on climate, vegetation and mammalian evolution in the Cenozoic of Eurasia.
Topics: Environment, Qaidam, Paleontology, Cenozoic, Evolution of mammals, Fossil, Tibetan plateau, Mammal