The position of the Earth’s landmasses in the Early Triassic.
- The rapid diversification of angiosperm taxa began in the mid-Cretaceous.
- At that time, there is an almost exponential increase in angiosperm diversity, and there does not appear to have been any major extinctions of groups in between.
- Despite the large numbers of taxa that are known from rather early in this diversification, there is no indication of where the taxa are coming from.
- D.I. Axelrod has suggested that we do not find early angiosperm fossils because the earliest angiosperms lived in dry, upland habitats where the were unlikely to be preserved as fossils.