A new study of the divergence time of angiosperm families shows that although most angiosperm families originated during the middle Cretaceous (~100–90 million years ago), the diversification of families into extant diversity was delayed until the Palaeocene (~66–56 million years ago), this time lag being geographically heterogeneous, and longer in tropical than in temperate and arid biomes.
- Santiago Ramírez-Barahona
- Hervé Sauquet
- Susana Magallón