**History and Taxonomy of Pteridospermatophyta**:
– Emergence of pteridosperms concept in the late 19th century
– Initial classification by German palaeobotanist Henry Potonié as Cycadofilices
– Identification of pteridosperms solely from the fossil record in the 19th century
– Taxonomic families like Physostomataceae and Lyginopteridaceae
– Consideration of pteridosperms as a paraphyletic grade-group
– Inclusion of Mesozoic groups with fern-like fronds in the pteridosperm classification
**Enduring Utility and Decline of Pteridosperms**:
– Informal use of pteridosperm grouping for non-angiosperm seed plants
– Description of fern-like fronds produced by seed plants as pteridosperms
– Decline of pteridosperms during the Mesozoic Era, mostly disappearing by the end of the Cretaceous Period
– Utility in understanding extinct seed plant groups and their systematic relationships
– Presence of fern-like fronds in many Palaeozoic and Mesozoic fossil floras
**Discovery and Attention on Pteridosperms**:
– Recognition of pteridosperms as the first extinct group of vascular plants identified solely from fossils
– Expansion of the concept in the 20th century to include Mesozoic groups with fern-like fronds
– Consideration of seed fern groups with potential ancestry to flowering plants
– The Age of Pteridosperms in the 20th century
– Importance of phylogenetic analysis techniques in forming meaningful hypotheses
**Scientific Publications on Pteridosperms**:
– Studies on Mesozoic seed ferns by Taylor et al. (2006)
– Pteridosperms as the backbone of seed-plant phylogeny by Hilton & Bateman (2006)
– Exploration of seed ferns from late Paleozoic and Mesozoic by Taylor & Taylor (2009)
– Discovery of new families of Permian gymnosperms and pteridosperms from China and Gondwana
– Various references on specific findings related to pteridosperms
**Research on Gymnosperms and Related Topics**:
– Comprehensive overview of gymnosperms including their classification, biodiversity, phytogeography, and ecology
– Study of gymnosperms in the Late Triassic era and the Heyday of gymnosperms
– Examination of Molteno fructifications and Lower Carboniferous Rocks
– Royal Society of Edinburgh Transactions with works focusing on petrified stems, early Pterophytina classification, and the introduction of Triradioxylon as a new genus
Pteridospermatophyta, also called "pteridosperms" or "seed ferns" are a polyphyletic grouping of extinct seed-producing plants. The earliest fossil evidence for plants of this type are the lyginopterids of late Devonian age. They flourished particularly during the Carboniferous and Permian periods. Pteridosperms declined during the Mesozoic Era and had mostly disappeared by the end of the Cretaceous Period, though Komlopteris seem to have survived into Eocene times, based on fossil finds in Tasmania.
| Pteridospermatophyta | |
|---|---|
| |
| Fossil seed fern leaves of Neuropteris (Medullosales) from the Late Carboniferous of northeastern Ohio. | |
| |
| Life restoration of Lepidopteris (Peltaspermales) | |
Scientific classification
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Spermatophytes |
| Division: | †Pteridospermatophyta |
| Groups included | |
| |
| Excluded | |
| |
| Synonyms | |
|
Pteridospermatopsida | |
With regard to the enduring utility of this division, many palaeobotanists still use the pteridosperm grouping in an informal sense to refer to the seed plants that are not angiosperms, coniferoids (conifers or cordaites), ginkgophytes or cycadophytes (cycads or bennettites). This is particularly useful for extinct seed plant groups whose systematic relationships remain speculative, as they can be classified as pteridosperms with no valid implications being made as to their systematic affinities. Also, from a purely curatorial perspective the term pteridosperms is a useful shorthand for describing the fern-like fronds that were probably produced by seed plants, which are commonly found in many Palaeozoic and Mesozoic fossil floras.