Archive | Gymnosperm

In this article we will discuss about Pteridospermales. After reading this article you will learn about: 1. Meaning of Pteridospermales 2. General Characters of Pteridospermales 3. Classification 4. Affinities. Meaning of Pteridospermales: The Pteridospermales are popularly known as "seed-ferns". They possessed fern-like foliage, bore seeds, and are, therefore, called pteridosperms. They first appeared on the earth in Upper Devonian times [...]

In this article we will discuss about Bennettitales. After reading this article you will learn about: 1. Meaning of Bennettitales 2. Origin of Bennettitales 3. Nomenclature, History and Distribution 4. Distinguishing Features 5. Classification 6. Affinities. Contents: Meaning of Bennettitales Origin of Bennettitales Nomenclature, History and Distribution of Bennettitales Distinguishing Features of Bennettitales Classification of Bennettitales Affinities of Bennettitales 1. [...]

The below mentioned article provides short notes on Williamsoniella. Williamsoniella belongs to family Wielandiellaceae of Bennettitales. Thomas (1915) described it as a Jurassic genus. Its fossils are found in the form of compressions. The best known and most investigated species is W. coronata (Fig. 6 19). The plant possessed a dichotomously branched stem bearing spirally arranged leaves. The leaves were [...]