Paleobotany is the study of fossil plants and their relationship to modern plants. Early angiosperms first appeared in the fossil record during the Lower Cretaceous period, around 130 million years ago. However, they diversified and dominated plant communities only later in the Cretaceous. Transitional fossils like Archaefructus provide evidence of early flowering plants, but their exact position is unclear. During the Lower and Mid-Cretaceous, there was an increase in the diversity of angiosperm leaves, pollen, and plant families, indicating the rapid radiation and rise of flowering plants.