نتایج جستجو برای: fossil record

تعداد نتایج: 121933  

Journal: :Science 1982
D M Raup J J Sepkoski

A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these ...

Journal: :Science 1993
C C Labandeira J J Sepkoski

Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly e...

Journal: :Science 1983
D M Raup J J Sepkoski S M Stigler

2010
Peter J. Wagner Kathleen Lyons

Many ecological and palaeontological studies focus on extinction. The fossil record is particularly important for studying long-term patterns in extinction: although analyses of extant phylogenies can estimate extinction rates (e.g. Alfaro et al. 2009) and even suggest mass extinctions (e.g. Crisp & Cook 2009), they cannot imply trilobites ever existed or that sphenodonts (now represented only ...

2006
David R. Begun

Hominoids, or taxa identified as hominoids, are known from much of Africa, Asia, and Europe since the Late Oligocene. The earliest taxa, fromAfrica, resemble extant hominoids but share with them mainly primitive characters. Middle and Late Miocene taxa are clearly hominoids, and by the end of the Middle Miocene most can be attributed to either the pongine (Pongo) or hominine (African ape and hu...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Hélène Morlon Todd L Parsons Joshua B Plotkin

Historical patterns of species diversity inferred from phylogenies typically contradict the direct evidence found in the fossil record. According to the fossil record, species frequently go extinct, and many clades experience periods of dramatic diversity loss. However, most analyses of molecular phylogenies fail to identify any periods of declining diversity, and they typically infer low level...

2013
Daril A. Vilhena Andrew B. Smith

Inference of past and present global biodiversity requires enough global data to distinguish biological pattern from sampling artifact. Pertinently, many studies have exposed correlated relationships between richness and sampling in the fossil record, and methods to circumvent these biases have been proposed. Yet, these studies often ignore paleobiogeography, which is undeniably a critical comp...

Journal: :Science 2003
David Elbaz Catherine J Cesarsky

The cosmic infrared background (CIRB) is a record of a large fraction of the emission of light by stars and galaxies over time. The bulk of this emission has been resolved by the Infrared Space Observatory camera. The dominant contributors are bright starburst galaxies with redshift z approximately 0.8; that is, in the same redshift range as the active galactic nuclei responsible for the bulk o...

Journal: :Proceedings. Biological sciences 2007
M A Wills

Biologists routinely compare inferences about the order of evolutionary branching (phylogeny) with the order in which groups appear in the fossil record (stratigraphy). Where they conflict, ghost ranges are inferred: intervals of geological time where a fossil lineage should exist, but for which there is no direct evidence. The presence of very numerous and/or extensive ghost ranges is often be...

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