Neritic environments, host of the highest marine biodiversity, are particularly sensitive to environmental changes. Their study allows us to understand how carbonate-producing ecosystems cope with climatic upheavals, but also shed important light on the evolution of critical parameters such as global sea-level fluctuations during these contorted times. This presentation will focus on the late Plienbachian – early Toarcian time interval, which is marked by repeated drastic environmental changes, out of which the Toarcian OAE stands as one of the most extreme environmental change of the Mesozoic. By looking at an exceptionally preserved geological record in the Central High Atlas Basin of Morocco, the role and weight of different environmental factors (such as seawater temperature, oxygen and nutrient levels, carbonate saturation state, sea-level change, etc.) on neritic carbonate production and demise will be discussed.