Sentence Examples with the word cordaitales

In the isolated seeds of Cordaitales and Pteridosperms, pollen-grains are often found within the pollen-chamber, and the pluricellular structure of these pollen-grains has been repeatedly demonstrated.

The class Cordaitales extends back to the Devonian, and it must be borne in mind that our knowledge of their fructifications is practically limited to representatives from the latest Palaeozoic horizons.

The Cordaitales (see Palaeobotany: Palaeozoic) are represented by extinct forms only, which occupied a prominent position in the Palaeozoic period; these plants exhibit certain features in common with the living Araucarias, and others which invite a comparison with the maidenhair tree (Ginkgo biloba), the solitary survivor of another class of Gymnosperms, the Ginkgoales (see Palaeobotany: Mesozoic).