Dynamics of origination and extinction in the marine fossil record

Abstract

The discipline-wide effort to database the fossil record at the occurrence level has made it possible to estimate marine invertebrate extinction and origination rates with much greater accuracy. The new data show that two biotic mechanisms have hastened recoveries from mass extinctions and confined diversity to a relatively narrow range over the past 500 million years (Myr). First, a drop in diversity of any size correlates with low extinction rates immediately afterward, so much so that extinction would almost come to a halt if diversity dropped by 90%. Second, very high extinction rates are followed by equally high origination rates. The two relationships predict that the rebound from the current mass extinction will take at least 10 Myr, and perhaps 40 Myr if it rivals the Permo-Triassic catastrophe. Regardless, any large event will result in a dramatic ecological and taxonomic restructuring of the biosphere. The data also confirm that extinction and origination rates both declined through the Phanerozoic and that several extinctions in addition to the Permo-Triassic event were particularly severe. However, the trend may be driven by taxonomic biases and the rates vary in accord with a simple log normal distribution, so there is no sharp distinction between background and mass extinctions. Furthermore, the lack of any significant autocorrelation in the data is inconsistent with macroevolutionary theories of periodicity or self-organized criticality.biodiversity ͉ macroevolution ͉ mass extinction

Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack

“…The Jurassic-Cretaceous boundary was earlier considered to be one of the major mass extinction events during the Phanerozoic (Sepkoski and Raup, 1986) with groups such as corals, brachiopods, bivalves, ammonites and fish all affected. As noted above, subsequent work has downgraded the boundary to a minor extinction event at most (Alroy, 2008). However, some recent studies have found evidence for a real diversity trough within terrestrial dinosaurs and marine reptiles (e.g., Mannion et al, 2011).…”

“…This is, in part, due to the lack of an agreed upon, chronostratigraphic framework for the Jurassic-Cretaceous boundary (Zakharov et al, 1996;Wimbledon et al, 2011;Michalík and Reháková, 2011;Guzhikov et al, 2012;Shurygin and Dzyuba, 2015). It is a time of contentious biotic changes, for which opinions have ranged from proposal of a putative mass extinction (Raup and Sepkoski, 1984) or a regional event (Hallam, 1986) or nonevent (Alroy, 2008;Rogov et al, 2010). Using large taxonomic occurrence databases, several recent studies (particularly of tetrapods) have re-examined the Jurassic-Cretaceous boundary, and note a sharp decline in diversity around the Jurassic-Cretaceous boundary (Barrett et al, 2009;Mannion et al, 2011;Upchurch et al, 2011;Tennant et al, 2016).…”

Environmental changes across the Triassic–Jurassic boundary and coeval volcanism inferred from elemental geochemistry and mineralogy in the Kendlbachgraben section (Northern Calcareous Alps, Austria)

“…The Triassic-Jurassic boundary (TJB) is preceded by one of the five largest Phanerozoic 58 biotic crises, the end-Triassic extinction (ETE) (Alroy, 2008;Raup and Sepkoski, 1982), 59…”

A triász és a jura időszak határán lezajlott globális krízis és annak nyomai magyarországi rétegsorokban

“…Jelenlegi ismereteink szerint a triász időszakot lezáró tömeges kihalás a fanerozoikum egyik legnagyobb kihalási rátájával jellemezhető eseménye volt (ALROY 2008(ALROY , 2014. Az ökológiai szempontból kedvezőtlen hatások, mint a glo bális felmelegedés és az óceán savasodása (l. alább) első sor ban a tengeri ökoszisztémát sújthatták, továbbá az ős ma radványok megőrződésének feltételei is jellemzően a ten ge rekben kedvezőbbek.…”