These reproductive shoots differ in many important respects from the flowers of recent Cycads, and chiefly on this account it is customary to include the plants in a separate genus, Bennettites, and in a separate group - the Bennettitales - distinct from that of the Cycadales including the existing Cycads.
The Lyginodendreae type of structure, however, appears to have formed the transition not only to the Cycadales, but also to the extinct family Cordaiteae, the characteristic Palaeozoic Gymnosperms (see p. 107).
With these occur several Conifers, among others Voltzia heterophylla and some twigs referred to the genus Albertia, bearing large leaves like those of Agathis australis and some of the Araucarias, also a few representatives of the Cycadales.
The scaly ramenta which occur in abundance on the leaf-stalk bases of fossil Cycads constitute another fern-character surviving in Mesozoic Cycadales.
Sphenozamites, chiefly from French localities, which are referred to 1 fronds, which therg is good reason to refer to the Cycadales in the Cycads because of their similarity to the pinnate fronds of Upper Triassic, Rhaetic, Jurassic and Wealden rocks in India, modern Cycadaceae.