Everything about Gigantopterid totally explained
Gigantopterids (
Gigantopteridales) is the name given to
fossils of a group of plants existing in the
Late Permian, until some 250 million years ago. Gigantopterids were among the most advanced
land plants of the
Paleozoic and disappeared soon after the massive
Permian–Triassic extinction event 251.4
million years ago. Though some lineages of these plants managed to persist initially, they either disappeared entirely or adapted radically,
evolving into undetermined descendants, as surviving life prospered again in much-altered ecosystems. One hypothesis proposes that at least some "gigantopterids" became the ancestors of
angiosperms and/or
Bennettitales and/or
Caytoniales..
Gigantopterid fossils were documented as early as
1883, but only investigated more thoroughly in the early 20th century. Some of their most significant evidence has been initially found in
Texas, but they may have been present worldwide: another key region for gigantopterid fossils is in
China, and the consolidation of all major
continents into
Pangea would have allowed for easy global dispersal. They were among the most striking and important plants of the
Cathaysian flora of
Sino-
Malaya, also called
Gigantopteris flora to reflect this.
Description
They bore many of the traits of
flowering plants, but are not known to have flowered themselves. Gigantopterid plants had simple, bilaterally symmetrical leaf structures, woody stems and spines. They grew new parts by producing shoots, like flowering plants. Judging from the fossil remains, they were probably robust plants with
fronds that resembled
fern fronds when young. When mature they were more like flowering plant
leaves with
reticulate venation arranged in a frond.
Gigantopteris nicotianaefolia for example is named thus because each of its
leaflets resembles a
tobacco leaf in shape.
They grew at least over 20 cm (around 10 in), probably over 50 cm (20 in) tall, depending on whether it grew as a scrambling vine (the initial assumption) or erect (nowadays considered more likely). Some were apparently
amphibious, while others thrived in rather
arid habitat.
The
vascular tissue contains
vessel elements and in at least some
taxa resembles that of the
Gnetophyta. They had a
cuticula similar to that of other seed plants. Some male
sporangia (
Gigantotheca,
Jiaochengia) and
seeds (
Gigantonomia,
Cornucarpus) have been tentatively referred to this group. While the sporangia are certainly not flowers, they differ from other sporangia of Permian plants.. However, many experts remain skeptical of the new name, because they consider such a move premature until more is known about the interrelationships of the
genera of "gigantopterids" and the relationships of these to other plants. It appears as if at least some of his divisions ought to prove useful when a more definite
phylogenetic,
systematic and
taxonomic arrangement for this group is eventually found. On the other hand, the Gigantopteridaceae would with near certainty have to be more narrowly circumscribed even if the Gigantopteridales are by and large verified as a
clade; they might even become limited to the two or so genera now placed in the Gigantopteridieae.
Proposed subfamilies and genera
Cathaysiopteridieae - may be synonym of Palaeogoniopteridieae
Further Information
Get more info on 'Gigantopterid'.
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