The Late Triassic Mass Extinction Event

Abstract

The Late Triassic extinction event is recognized as one of the five largest such events of the Phanerozoic and is now generally believed to have been caused by global warming and concomitant environmental changes triggered by emplacement of the Central Atlantic Magmatic Province. The trace-fossil record, both terrestrial and marine, shows signs of change and perturbation through the extinction interval and across the Triassic–Jurassic boundary. On land, there is a decline in nondinosaurian ichnotaxa coincident with a rise in large dinosaur ichnotaxa. In the marine realm, there is a temporary reduction in ichnodiversity and the size and depth of individual ichnotaxa, coincident with peak global warming, followed by an increase in size during Hettangian and Sinemurian. Although data are relatively sparse, the Triassic–Jurassic trace-fossil record suggests that major changes to the tracemaker communities on land and in the sea may have been driven by coeval climatic and environmental change.