نتایج جستجو برای: late cambrian

تعداد نتایج: 197730  

Journal: :Smithsonian Contributions to Paleobiology 1993

2007
JONATHAN R. HENDRICKS BRUCE S. LIEBERMAN

ONE of John Shergold’s abiding research interests, and an area in which he made fundamental contributions to the fields of palaeontology and geology, was the study of Cambrian arthropods in general, and trilobites in particular (e.g., Shergold 1977, 1988, 1991; Shergold et al. 1990; Shergold & Laurie 1997). Here we focus on what Cambrian arthropods, including trilobites, can tell us about the n...

Journal: :Geological Magazine 2023

Abstract The Sichuan Basin was a part of the Yangtze Carbonate Platform (YCP) during Cambrian–Ordovician, and marine carbonates were deposited in basin this interval. Although previous studies have evaluated paleogeography, paleoclimate paleoecology basin, they primarily focused on biological evolution basin; however, analysis paleogeography is lacking. This study integrated outcrop sedimentolo...

2006
RUSSELL S. SHAPIRO STANLEY M. AWRAMIK

The distinctive, branched thrombolite, Favosamaceria cooperi new group and form, is found widely in the Great Basin, USA, where it is restricted to the Late Cambrian Saukia trilobite Zone. This thrombolite is distinguished by a hedgerow, mazelike organization of ridges similar to garden walls (maceriae) in plan view, branching of ridges into daughter ridges and columns, the polymorphic nature o...

2003
Joseph L. Kirschvink Timothy D. Raub

The dramatic diversification of animal groups known as the Cambrian Explosion (evolution’s ‘Big Bang’) remains an unsolved puzzle in Earth Science. The Vendian–Cambrian interval is characterized by anomalously high rates of apparent plate motion, interpreted as True Polar Wander (TPW), and by more than a dozen large, high-frequency perturbations in carbon isotopes that dwarf all others observed...

Journal: :Papers and Proceedings of The Royal Society of Tasmania 1986

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1998
F J Ayala A Rzhetsky F J Ayala

The time of origin of the animal phyla is controversial. Abundant fossils from the major animal phyla are found in the Cambrian, starting 544 million years ago. Many paleontologists hold that these phyla originated in the late Neoproterozoic, during the 160 million years preceding the Cambrian fossil explosion. We have analyzed 18 protein-coding gene loci and estimated that protostomes (arthrop...

Journal: :Geological Society, London, Special Publications 2008

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Matthew R Saltzman Seth A Young Lee R Kump Benjamin C Gill Timothy W Lyons Bruce Runnegar

A rise in atmospheric O(2) has been linked to the Cambrian explosion of life. For the plankton and animal radiation that began some 40 million yr later and continued through much of the Ordovician (Great Ordovician Biodiversification Event), the search for an environmental trigger(s) has remained elusive. Here we present a carbon and sulfur isotope mass balance model for the latest Cambrian tim...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید