Extinction-Recovery Pattern of Level-Bottom Faunas Across the Triassic-Jurassic Boundary in Tibet: Implications for Potential Killing Mechanisms

Early Triassic Microbial Spheroids in the Virgin Limestone Member of the Moenkopi Formation, Nevada, Usa

“…Following the extinction (E), a lag phase marks a time in− terval in which no significant radiation and increase in alpha diversity is ob− served (Ewin 2001). The duration of this lag phase may be variable or it could even be absent (Hautmann et al 2008) but it is commonly postulated for the end−Permian mass extinction (e.g., Erwin 2001). After initiation of diversification (T 1 , start of recovery interval 1), competition within habitats increases following recovering alpha diversity.…”

Macrofaunal Response to the End-Triassic Mass Extinction in the West-Tethyan Kossen Basin, Austria

“…The ocean acidification model predicts an increased extinction risk for taxa with an aragonite or high-Mg calcite skeletal mineralogy (Hautmann, 2004;Knoll et al, 2007;Hautmann et al, 2008a) and, thus, offers a possible explanation for the preferential extinction of reef communities, ammonoids, and aragonitic bivalves at the end of the Triassic (Hautmann et al, 2008a(Hautmann et al, , 2008b, which is in contrast to groups with such noncalcareous skeletons as radiolarians that had no significantly increased extinction risk (Kiessling and Danelian, 2011;Hönisch et al, 2012). Somewhat counterintuitively, taxa with massive or thick-shelled skeletons, including strongly ornamented forms, also appear to be at an elevated extinction risk, because decreased CaCO 3 saturation of seawater raises energy expenditure for biocalcification, which puts such taxa at a selective disadvantage (Hautmann, 2006;Knoll et al, 2007;Veron, 2008Veron, , 2011Kiessling and Simpson, 2011).…”

“…4) that may have served as protection from an acidic aqueous environment. In summary, 80% of the observed species had partly calcitic or noncalcareous shells, thus, aragonitic taxa are clearly underrepresented in comparison to levelbottom faunas from pre-extinction times (Hautmann, 2001;Hautmann et al, 2008b, see also Tomašových, 2006and Kiessling et al, 2007 for additional data on the Kö ssen fauna). Similarly, Clémence et al (2010a) found a dominance of noncalcareous (agglutinated) foraminifers at the base of the Tiefengraben Member, possibly also indicating reduced seawater pH rather than reduced salinity.…”

Revisión De Los Biocoremas Marinos Globales Del Jurásico Según La Distribución De Los Moluscos Bivalvos

“…La recuperación relativamente rápida de varios grupos sistemáticos de bivalvos (Hallam, 1981(Hallam, , 1996McRoberts et al, 1995;Wignall y Bond, 2008;Hautmann et al, 2008;Damborenea et al, 2017), junto con el constante incremento de los taxones endémicos, permitió el reconocimiento de faunas Boreales, Tethyanas y Australes ya para el Sinemuriano tardío-Pliensbachiano temprano (Fig. 1), con dos unidades en el Reino Austral y cinco en el Reino del Tethys.…”