Agathe Toumoulin

Masaryk University | MUNI · Department of Botany and Zoology

The Asian monsoons are triggered by complex interactions between the atmosphere, Asian and African orography, and the surrounding oceans, resulting in highly seasonal climate and specific regional features. It was thought that the Asian monsoon was established during the Neogene, but recent evidence for monsoon-like precipitation seasonality occurr...

The Jurassic vegetation of Antarctica remains poorly known and, while there have been several reports of large fossil trees from that time period across the continent, detailed anatomical studies of their wood are extremely scarce. Here we describe new silicified woods of Early Jurassic (probably Toarcian) age from Carapace Nunatak, South Victoria...

Objectives This study presents the Integrated Leaf Trait Analysis (ILTA), a workflow for the combined application of methodologies in leaf trait and insect herbivory analyses on fossil dicot leaf assemblages. The objectives were (1) to record the leaf morphological variability, (2) to describe the herbivory pattern on fossil leaves, (3) to explore...

At the junction of greenhouse and icehouse climate states, the Eocene–Oligocene Transition (EOT) is a key moment in Cenozoic climate history. While it is associated with severe extinctions and biodiversity turnovers on land, the role of terrestrial climate evolution remains poorly resolved, especially the associated changes in seasonality. Some pal...

Recent studies suggest increasing sensitivity to orbital variations across the Eocene-Oligocene greenhouse to icehouse climate transition. However, climate simulations and paleoenvironmental studies mostly provide snapshots of the past climate, therefore overlooking the role of this short-term variability in driving major environmental changes and...

At the junction of greenhouse and icehouse climate phases, the Eocene-Oligocene Transition (EOT) is a key moment in the history of the Cenozoic climate. Yet, while it is associated with severe extinctions and biodiversity turnovers, terrestrial climate evolution remains poorly resolved. Paleobotanical and geochemical continental records suggest a m...

L'Éocène (56 - 33,9 Ma) est une époque charnière dans l’évolution du climat au cours du Phanérozoïque. Elle est caractérisée par des changements de géographie importants, des évènements de réchauffements climatiques extrêmes, mais aussi, après près de 260 Ma de températures globalement plus élevées par un long refroidissement, initiant l’englacemen...

PREMISE: Fossil leaf traits can enable reconstruction of ancient environments and climates. Among these, leaf size has been particularly studied because it reflects several climatic forcings (e.g., precipitation and surface temperature) and, potentially, environment characteristics (e.g., nutrient availability, local topography, and openness of veg...

The opening of the Drake Passage (DP) during the Cenozoic is a tectonic event of paramount importance for the development of modern ocean characteristics. Notably, it has been suggested that it exerts a primary role in the onset of the Antarctic Circumpolar Current (ACC) formation, in the cooling of high‐latitude South Atlantic waters and in the in...

This dataset combines the oceanic and atmospheric outputs from various experiments modelling the Drake Passage opening during the Eocene (Toumoulin et al. 2020, Paleoceanography and Paleoclimatology). It includes 4 simulations with a 40 Ma paleogeography, a 1120 ppm pCO2 and different depths of the Drake Passage (0, 100, 1000, 2500m). Experiments w...

In the current context of climate change, understanding warmer climate's functioning and response to pCO2 forcing is becoming essential. From the Permian to the Eocene (ca 260 Ma to 34 Ma), Earth has experienced a greenhouse climate state. It is defined by globally high pCO2 and annual temperatures, and by the absence of permanent ice-sheets. In th...

The impact of the Drake Passage (DP) opening on climate is being debated for dozens of years. Indeed, being one of the major geographical changes occurring during the Eocene and at the beginning of a global climate cooling, it has often generated a lot of interest. To date, even though the overall signal remains unclear, it is considered as one of...

Fossil leaves are interesting tools to reconstruct ancient environments and climates. However, they are sometimes poorly preserved and fragmented, what limits the applicability of their leaf-traits and physiognomic characters (i.e. size and shape) within palaeoecological approaches. The present study aims to deal with this problem and build a metho...

Among the few Lower Jurassic sites with plant remains known from Antarctica, Carapace Nunatak, in South Victoria Land, is emerging as one of the richest. It contains different types of plant fossils (pollen, silicified plants, compressions/impressions, and fusain), which opens the door to promising multidisciplinary studies on past biodiversity and...