New range data for marine invertebrate species across the early Toarcian (Early Jurassic) mass extinction

摘要: Abstract: We have reinvestigated the marine mass extinction interval that occurred during early Toarcian, which was a time of widespread anoxia. The ranges benthic invertebrates are significantly altered using new observations from Cleveland Basin, UK. Goniomya rhombifera is reported for first Whitby Mudstone Formation and together with an increased epifaunal bivalve diversity indicates brief, relatively oxygenated period towards end event. data, published results, suggest three apparent horizons on global scale; just above Pliensbachian–Toarcian boundary, following two in semicelatum ammonite Subzone. As result Signor–Lipps effect there may be only one, or possibly two, true extinctions. youngest horizon coincides abrupt carbon isotope shifts characterize this interval, increases sea surface temperature, continental weathering rates, seawater Pseudomytiloides dubius abundant macroinvertebrate most hostile environmental conditions but it all other species almost entirely absent many thousands years immediately after each negative shift. Supplementary material: A compilation Late Pliensbachian Early Toarcian biotic changes discussion systematics key faunal elements available at http://www.geolsoc.org.uk/SUP18353.