منابع مشابه
Interpreting Late Precambrian Microfossils
Chia-Wei Li et al. describe microfossils found in Doushantuo phosphate rocks from Guizhou Province, South China that are about 580 million years old (1). Well-preserved macroscopic multicellular fossils associated with prokaryotic and eukaryotic microfossils from the same source rocks have been documented in several studies (2– 6). The Doushantuo fossils are outstanding in both preservation qua...
متن کاملChiral biomarkers and microfossils in carbonaceous meteorites
Homochirality of the biomolecules (D-sugars of DNA and RNA and L-amino acids of proteins) is a fundamental property of all life on Earth. Abiotic mechanisms yield racemic mixtures (D/L=1) of chiral molecules and after the death of an organism, the enantiopure chiral biomolecules slowly racemize. Several independent investigators have now established that the amino acids present in CI1 and CM2 c...
متن کاملELECTRON MICROSCOPY OF ANCIENT MICROFOSSILS Mentor:
Prof. Xiao’s current research focuses on the biological evolution and environmental changes in the Proterozoic Eon (2500 to 543 million years ago). He has been working on some of the most important and exquisitely preserved microfossils from the ca. 600-million-year-old Doushantuo Formation in South China. These microfossils include multicellular red algae and animal embryos at successive cleav...
متن کاملFeatures for the Classification of Marine Microfossils
Features for a new application in pattern recognition are presented. The objects to be classiied are coccoliths (marine microfos-sils). Since the objects diier both in their outline and in their internal structure the features developed take into consideration both kinds of variability. The features concerning the internal structure are computed on the grey-value images produced by a scanning e...
متن کاملMicrofossils of Cyanobacteria in Carbonaceous Meteorites
During the past decade, Environmental and Field Emission Scanning Electron Microscopes have been used at the NASA/Marshall Space Flight Center to investigate freshly fractured interior surfaces of a large number of different types of meteorites. Large, complex, microfossils with clearly recognizable biological affmities have been found embedded in several carbonaceous meteorites. Similar forms ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Geological Magazine
سال: 1962
ISSN: 0016-7568,1469-5081
DOI: 10.1017/s0016756800058507