CLASS LYGINOPTERIDOPSIDA (=HYDRASPERMAN
These plants have a fossil history which ranges from the upper Devonian
to the Permian. They have seeds in cupules and synangiate pollen organs. This may be an
These plants are common in the Carboniferous. They have stems up to 3
cm in diameter which contain pith with vascular bundles. The primary xylem is
leaves are up to .5 m long and have dichotomous venation. The seeds are barrel-shaped
(about 5mm long) and are surrounded by a single integument. The beak of the nucellus
(megasporangium) forms a pollen chamber. The seed occurs in a cupule.
Elkinsia, Eusphenopteris, Heterangium, Karenopteris, Lagenostoma, Lyginopteris,
CLASS MEDULLOSOPSIDA (=MEDULLOSAN
These plants are common in the Carboniferous. They have polystelic
stems with a trunk up to 5m tall with a spray of fronds at the top. Leaves have sunken
stomata. The seeds have an integument of several layers and form a micropyle. The nucellus
ids free from the integuments. The pollen-bearing structures occur in a cup. Pollen wall
has a single long suture.
Neuralethopteris, Lonchopteris, Lonchopteridium, Cardioneuopteris
Odontopteris, Macroneuropteris, Neurodontopteris, Neurocallipteris,
Barthelopteris, Lescuropteris, Palaeoweichselia
CLASS CALLISTOPHYTOPSIDA (=CALLISTOPHYTALEAN
These plants are found in the Carboniferous and Permian periods. They
have stems which are relatively thin (1.8-0.3cm in diameter) with a solid pith. Secondary
tissue is well developed. The seeds are small with 3 integument layers (the nucellus is
free). Pollen is saccate. One family (Emplectopteridaceae) os also
known as the gigantopterids, which are highly
advanced plants of the late Permian and may have persisted into the lower
Triassic. The vascular tissue of gigsantopterids contained vessels and
the mature leaves had net veins; their strobili resembled those of
Angarocarpus, Callandrium, Callistophyton,
Callospermarion, Diksonites, Eremopteris, Gondwanotheca, Idanothekion,
CLASS PELTASPERMOPSIDA (=PELTASPERMALEAN
These plants occur in the Triassic. They have small fern-like leaves.
The pollen is saccate; the pollen organs resemble those of Lyginopteris.
These plants occur in the Permian and Triassic. Seeds occur on the
lower surface of an umbrella-like organ.
Antevsia, Callipteris, Lepidopteris,
CLASS CAYTONIOPSIDA (=HIGHER SEED
These plants occur in the Mesozoic and have recurved cupules in which
the seeds occur.
These plants occur in the Triassic to the Cretaceous. Seeds occur in
circular sacs with slits. Pollen is small and is winged with 2 bladders.
Caytonanthus, Caytonia, Sagenopteris.
ORDER GLOSSOPTERIDALES (=ARBERIALES)
These plants occur from the Permian to the Triassic. They have a
cluster of seeds attached to a common receptacle in the axil of certain leaves. This
group also includes the gigantopterids
Glossopteridaceae: Glossopteris, Scopus
Cathaysiopteris, Cathaysiopteridium, Gigantoclea, Gigantopteris, Gothanopteris,
Gigantopteridium, Palaeogoniopteris, Zeilleropteris, Delnortea,
Emplectopteridium, Emplectopteris, Neogigantopteridium, Vasovinea.