The distinctive trace fossil Chubutolithes gaimanensis n. ichnosp. occurs in Casamayoran (early Eocene) and Colhu6haupian (late Oligocene) alluvial rocks of the Sarmiento Formation in eastern Chubut Province, Argentina. Though known for nearly 70 years, its origin has remained obscure. Examination of new specimens and comparisons with modem analogs demonstrate that specimens of Chubutolithes re...

in this research, elemental and chemical characteristics of atmospheric dust particulates including major and trace elements in two synoptic meteorological stations (abadan and urmia cities) during dust events and ambient periods have been evaluated. results showed that during dust events to ambient periods in both stations, major elements including ca, mg, al and trace elements comprised p and...

Thallium is commonly found with lead, zinc, iron, tellurium and the alkalis . It is normally present only at trace level (¡10 μg L−1) in natural waters. It is toxic and is on several regulatory lists . Determination of trace amounts of thallium is of great importance because of its toxic nature and also because of its increasing industrial applications . The main sources of thallium pollution a...

Early Cretaceous body and trace fossils in Victoria, Australia, establish the oldest known presence of parastacid crayfish (Decapoda: Astacidea, Parastacoidea) in freshwater environments of Australia, and the oldest known crayfish in Gondwana. Parastacid body fossils, comprised of a partial abdomen (Palaeoechinastacus australianus, gen. et sp. nov.) and two chelae, are from a fluvial deposit in...

The ichnological record can provide invaluable insight into the evolution of behaviour. Much of the current work in so-called "artificial life" and artificial neural networks is applicable to ethological paleobiology. Some preliminary experiments in this direction are presented here. A computer generated community of detritus feeders was simulated with the individuals in each generation being s...

Urban areas are increasingly recognized as a globally important source of methane to the atmosphere; however, the location of methane sources and relative contributions of source sectors are not well known. Recent atmospheric measurements in Los Angeles, California, USA, show that more than a third of the city’s methane emissions are unaccounted for in inventories and suggest that fugitive foss...

scaled down to nearer 670 million years5, bringing the figures more into line with the fossil record. A 'late arrival' model would also imply that the evolution of the main animal groups took place both late in Earth's history, and rapidly-perhaps in response to the evolution ofHox genes6 or to the lifting of some external constraint such as insufficient atmospheric oxygen2. So should these sup...

Owing to the delicate nature of fossil microorganisms and inherent difficulties for discriminating true fossils from artifacts, an important challenge is to extract unequivocal biogenic information from individual microfossils using high-resolution, nondestructive and sensitive techniques. Here, we use combined synchrotron (X-ray microfluorescence, X-ray absorption near-edge structure and infra...

The trace fossil assemblages from the Unit 2 of Deh-Sufiyan Formation are described for the first time from The Central Alborz Range of northern Iran,  improving the record of the assemblages in the Cambrian of the Middle East. Twenty-one ichnogenera have been identified in the Deh-Sufiyan Formation, namely Arenicolites, Bergaueria, Chondrites, Circulichnus, Cruziana, Diplichnites, Didymaulichnu...