Knowledge of the evolution of the grassland biome throughout the Earth's environmental history is important for the reconstruction of links between diversification/extinctions events and climate. Biomes are now being impacted by anthropogenic environmental change on an unprecedented scale, and one mean of understanding how component species will react is to study the effects of past environmental changes. Hence, understanding the evolutionary history of grassland ecosystems in the context of past biotic and abiotic changes is relevant to the way we will manage them under future environmental change. A new perspective on the history of the grassland biome is beginning to emerge from key developments in palaeontology and molecular phylogenetics that will be integrated interdisciplinary and multidisciplinary in the present project for the first time. GRASSLANDS aimed at understanding the timing and nature of grasslands' most important components, the grass (Poaceae) and daisy (Asteraceae) families, through the combination of fossil data, molecular phylogenetics and computational approaches. The potential contribution of GRASSLANDS to our understanding of the evolutionary history of these families and grassland ecosystems in general is significant and will certainly provide new insights into the rise of flowering plants as the dominant components of almost every terrestrial ecosystems.