This article provides a summary on Views Regarding the Time of Origin of Earliest Angiosperm. We have to depend almost entirely upon fossil evidence for the determination of the first traces of angiosperms. Unfortunately, due to lack of proper fossil records, palaeobotanical studies have not been able to solve the mystery about the earliest angiosperms. There are several views regarding [...]
The following points highlight the top nine theories about ancestors of angiosperms. Some of the theories are: 1. The Isoetes - Monocotyledon Theory 2. The Coniferales-Amentiferae Theory 3. The Gnetaies'-Angiosperm Theory 4. The Anthostrobilus (Bennettitalean) Theory 5. The Caytonialean Theory 6. The Stachyospory-Phyllospermae Theory 7. The Pteridosperm Theory and Others. 1. The Isoetes - Monocotyledon Theory: This theory was proposed [...]
The below mentioned article provides a short notes on Geographic Location of the Origin of Angiosperms. The geographic origin of the angiosperms has been under considerable debate. Just as the fossil evidence is insufficient to decide the time, as well as the nature of ancestors of angiosperms, it is also inadequate to settle the problem of the place of origin. [...]