The progymnosperms are an extinct group of woody, spore-bearing plants that is presumed to have evolved from the trimerophytes, and eventually gave rise to the gymnosperms, ancestral to acrogymnosperms and angiosperms (flowering plants).[1] They have been treated formally at the rank of division Progymnospermophyta or class Progymnospermopsida (as opposite). The stratigraphically oldest known examples belong to the Middle Devonian order the Aneurophytales, with forms such as Protopteridium, in which the vegetative organs consisted of relatively loose clusters of axes.[2]Tetraxylopteris is another example of a genus lacking leaves. In more advanced aneurophytaleans such as Aneurophyton these vegetative organs started to look rather more like fronds,[3] and eventually during Late Devonian times the aneurophytaleans are presumed to have given rise to the pteridosperm order, the Lyginopteridales. In Late Devonian times, another group of progymnosperms gave rise to the first really large trees known as Archaeopteris. The latest surviving group of progymnosperms is the Noeggerathiales, which persisted until the end of the Permian.[4]
Other characteristics:
Vascular cambium with unlimited growth potential is present as well as xylem and phloem.
Ancestors of the earliest seed plants as well as the first true trees.
Strong monopodial growth is exhibited.
Some were heterosporous but others were homosporous.
^Stewart WN, Rothwell GW (1993). Paleobiology and the evolution of plants. Cambridge University Press. p. 521pp.
^Lang WH (1926). "II.—Contributions to the Study of the Old Red Sandstone Flora of Scotland. I. On Plant-Remains from the Fish-Beds of Cromarty. II. On a Sporangium-bearing Branch-System from the Stromness Beds". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 54 (2): 253–79. doi:10.1017/S0080456800027599. S2CID 131163187.
^Serlin BS, Banks HP (1979). "Morphology and anatomy of Aneurophyton, a progymnosperm from the Late Devonian of New York". Palaeontographica Americana. 8: 343–359.
^Wang J, Hilton J, Pfefferkorn HW, Wang S, Zhang Y, Bek J, et al. (March 2021). "Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation". Proceedings of the National Academy of Sciences of the United States of America. 118 (11): e2013442118. Bibcode:2021PNAS..11813442W. doi:10.1073/pnas.2013442118. PMC 7980368. PMID 33836571.
The progymnosperms are an extinct group of woody, spore-bearing plants that is presumed to have evolved from the trimerophytes, and eventually gave rise...
Archaeopteris is an extinct genus of progymnosperm tree with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper...
Devonian period, several groups, including the lycopods, sphenophylls and progymnosperms, had independently evolved "megaspory" – their spores were of two distinct...
lycopods, ferns, seed plants (seed ferns, from earlier progymnosperms), first trees (the progymnosperm Archaeopteris), and first winged insects (palaeoptera...
prevailed, the Noeggerathiales, an extinct group of tree fern-like progymnosperms were a common component of the flora The earliest Permian (~ 298 million...
occurred independently in several separate lineages of vascular plants, in progymnosperms like Archaeopteris, in Sphenopsida, ferns and later in the gymnosperms...
forests of primitive plants existed: lycophytes, horsetails, ferns, and progymnosperms evolved. Most of these plants had true roots and leaves, and many were...
and by the Late Devonian this first forest was accompanied by the progymnosperms, including the first large trees Archaeopteris. The Late Devonian extinction...
for various early trees looked like. The paleosols associated with progymnosperm trunks are interpreted to not have grown in soils similar to the type...
the clubmosses, the ferns including the arborescent horsetails, and progymnosperms. This occurred as part of the process of evolution of the timing of...
seasons[clarification needed] are evident in Devonian and Carboniferous progymnosperm forests. Lepidodendron forests dating to the Carboniferous period have...
years ago. Early characteristics of seed plants are evident in fossil progymnosperms of the late Devonian period around 383 million years ago. It has been...
ferns, lepidosigillarioid lycopsids, and aneurophyte and archaeopterid progymnosperms. Fish were also undergoing a huge radiation, and tetrapodomorphs, such...
Middle Devonian, shrub-like forests existed: lycophytes, horsetails and progymnosperm. This greening event also allowed the diversification of arthropods...
Progymnosperms reported from the Joggins Formation Genus Species Location Stratigraphic position Material Images Adiantites A. adiantoides Cordaianthus...
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