Search

The rise of calcareous nannoplankton in Mesozoic oceans has deeply impacted ocean chemistry and contributed to shape modern oceans. Nevertheless, the calcareous nannoplankton colonization of past marine environments remains poorly understood. Based on an extensive compilation of published and unpublished data, we show that their accumulation rates in sediments increased from the Early Jurassic (~ 200 Ma) to the Early Cretaceous (~ 120 Ma), although these algae diversified up to the end of the Mesozoic (66 Ma). After the middle Eocene (~ 45 Ma), a decoupling occurred between accumulation rates, diversity and coccolith size. The time series analysed points toward a three-phase evolutionary dynamic. An Invasion phase of the open-ocean realms was followed by a Specialization phase occurring along with taxonomic diversification, ended by an Establishment phase where few small-sized species dominated. The current hegemony of calcareous nannoplankton in the World Ocean results from a long-term and complex evolutionary history shaped by ecological interactions and abiotic forcing. [ABSTRACT FROM AUTHOR]

The article presents the study on the Toarcian oceanic anoxic events (T-OAE) during the Toarcian period. The study shows that black shales were deposited on the pericontinental shelves of Pangaea during the early Toarcian period and is believed to represent oceanic anoxic event. The study also mentions that the distribution of black shales during the T-OAE is similar to the Mesozoic OAE.

Focuses on the evidence which shows that Earth's climate was much warmer during the Cretaceous period than it is today. List of material evidence; Analyses of sediments retrieved from a drifting ice island; Testament produced by Jenkyns and colleagues.