Peltaspermales Temporal range: Some specimens From the Jurassic-Cretaceous boundary of Australia may belong to the Group | |
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Life restoration of the Lepidopteris plant, with Lepidopteris ottonis foliage and Antevsia zeilleri pollen-producing microsporophylls, from the Late Triassic of Europe | |
Life restoration of Furcula granulifer from the Late Triassic of Greenland | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Spermatophytes |
Order: | † Peltaspermales Delevoryas 1979 [1] |
Families and genera | |
See text |
The Peltaspermales are an extinct order of seed plants, often considered "seed ferns". [2] They span from the Late Carboniferous to the Early Jurassic or the Jurassic-Cretaceous Boundary. It includes at least one valid family, Peltaspermaceae, which spans from the Permian to Early Jurassic, which is typified by a group of plants with Lepidopteris leaves, Antevsia pollen-organs, and Peltaspermum ovulate organs, though the family now also includes other genera like Peltaspermopsis , Meyenopteris and Scytophyllum . [3] Along with these, two informal groups (the "Supaioids" [4] [5] and the "Comioids" [6] ) of uncertain taxonomic affinities exist, each centered around a specific genus ; Supaia and Comia, known from the Early Permian of the Northern Hemisphere, especially of North America. [4] [6] Both the "Comioids" and the "Supaioids" are associated with the peltaspermacean ovulate organ Autunia (also known as Sandrewia). [7] [8] The Late Triassic-Middle Jurassic genus Pachydermophyllum may also have affinities to the peltasperms. [3]
The morphology of peltasperm leaves is highly variable, ranging from dissected pinnate (fern-like) to forked and simple morphologies. The leaves of many peltasperms have "monocyclic stomata with wedge-shaped subsidiaries ending in a beak-like papilla overarching the guard cells", something which is found among other seed plant groups. The seed-bearing organs are generally fan-shaped or peltate. [9]
It is unclear whether the broad grouping of peltasperms as a whole is monophyletic. [2] Some authors have suggested that some peltasperms may have close affinities to corystosperms, another group of extinct seed plants. [3] Meyen (1987) argued that Peltaspermales were ancestral to Ginkgoales, due to similarities between certain peltasperm form genera ( Tatarina , Kirjamkenia , Stiphorus , Antevsia) and the extinct gingko Glossophyllum, and grouped peltasperms with Ginkgoales as part of Ginkgoopsida. [10] Later authors have considered the position of Peltaspermales within seed plants to be uncertain. [9]
It is suggested that at least some peltasperms may have been insect pollinated, with Pemian members of the long-probiscis scorpionfly family Protomeropidae from Russia associated with peltasperm pollen. The insects are suggested to have fed on pollination drops produced by peltasperm reproductive organs. [11]
During the late Paleozoic, peltasperms are primarily known from the Northern Hemisphere, [3] with Lepidopteris first appearing in the region during the Late Permian. [12] During the Triassic, Lepidopteris became globally distributed and was abundant, especially during the Late Triassic. Lepidopteris populations collapsed during the end-Triassic mass extinction, [3] [13] [14] with small populations persisting in Patagonia into the Early Jurassic. [3] The genus Pachydermophyllum , along specimens referred as Lepidopteris? from the Battle Camp Formation of Clack Island, of latest Jurassic or earliest Cretaceous age may indicate an even longer survival in Gondwana. [15]
Ginkgoales are a gymnosperm order containing only one extant species: Ginkgo biloba, the ginkgo tree. The order has a long fossil record extending back to the Early Permian around 300 million years ago from fossils found worldwide.
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance to palms or ferns, they are sometimes mistaken for them, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. Both male and female cycads bear cones (strobili), somewhat similar to conifer cones.
Glossopteris is the largest and best-known genus of the extinct Permian order of seed plants known as Glossopteridales. The name Glossopteris refers only to leaves, within the framework of form genera used in paleobotany.
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.
Williamsonia is a genus of plant belonging to Bennettitales, an extinct order of seed plants. Within the form classification system used in paleobotany, Williamsonia is used to refer to female seed cones, which are associated with plants that also bore the male flower-like reproductive structure Weltrichia.
Dicroidium is an extinct genus of fork-leaved seed plants. It is the archetypal genus of the corystosperms, an extinct group of seed plants, often called "seed ferns", assigned to the order Corystospermales or Umkomasiales. Species of Dicroidium were widely distributed and dominant over Gondwana during the Triassic. Their fossils are known from South Africa, the Arabian Peninsula, Australia, New Zealand, South America, Madagascar, the Indian subcontinent and Antarctica.
Emplectopteridaceae is an extinct family of pteridosperms known mainly from Permian floras of the Cathaysian Realm. They were mostly shrubby plants with a scrambling or upright habit, and favoured a range of habitats from arid to moist or even aquatic.
Lepidopteris is a form genus for leaves of Peltaspermaceae, an extinct family of seed plants, which lived from around 260 to 190 million years ago, from the Late Permian to Early Jurassic. Fossils of the genus have been found across both hemispheres. Nine species are currently recognized.Lepidopteris was a common and widespread seed fern, which survived the Permian-Triassic extinction event but was largely wiped out by the Triassic-Jurassic extinction event. Lepidopteris callipteroides is especially common between the first two episodes of the Permian-Triassic extinction event, and L. ottonis forms a comparable acme zone immediately before the Triassic-Jurassic extinction event. Lepidopteris would persist into the Early Jurassic in Patagonia, represented by the species Lepidopteris scassoi.
Umkomasia is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. He recognized on the basis of cuticular similarities that the same plant produced pollen organs Pteruchus and the leaves Dicroidium. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with Umkomasia being restricted to the Triassic.
Pteruchus is a form genus for pollen organs of the seed fern (Pteridospermatophyta family Umkomasiaceae. It was first described by Hamshaw Thomas from the Umkomaas locality of South Africa. It is associated with the seed bearing organs Umkomasia and Dicroidium leaves.
Corystosperms are a group of extinct seed plants belonging to the family Corystospermaceae assigned to the order Corystospermales or Umkomasiales. They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. Corystosperms are typified by a group of plants that bore forked Dicroidium leaves, Umkomasia cupulate ovulate structures and Pteruchus pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept sensu lato, such as the "doyleoids" from the Early Cretaceous of North America and Asia. A potential corystosperm sensu lato, the leaf genus Komlopteris, is known from the Eocene of Tasmania, around 53-50 million years old, over 10 million years after the Cretaceous–Paleogene extinction event.
Dictyopteridium is an extinct genus of plants belonging to Glossopteridaceae, but the name is used only for compression fossils of elongate multiovulate reproductive structures adnate to Glossopteris leaves. Permineralized remains identical to Dictyopteridium have been referred to the organ genus Homevaleia
Lepidopteris callipteroides is a form species for leaves of Late Permian Pteridospermatophyta, or seed ferns, which lived from around 252 million years ago in what is now Australia, and Madagascar. Lepidopteris callipteroides was an immediate survivor of the largest Permian-Triassic extinction event, migrating southward with the post-apocalyptic greenhouse spike.
This article records new taxa of plants that are scheduled to be described during the year 2018, as well as other significant discoveries and events related to paleobotany that occurred in the year 2018.
This article records new taxa of fossil plants that are scheduled to be described during the year 2020, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2020.
Czekanowskiales, also known as Leptostrobales, are an extinct group of seed plants. Members of the family are distinguished by persistent leaves borne on deciduous short shoots, subtended by scale-like leaves. The leaves are highly dissected. They likely grew as trees and shrubs. The main ovulate structure of Czekanowskiales, Leptostrobus, consists of bivalved seed-bearing round capsule-like structures arranged along a long axis. The fossil record of Czekanowskiales is largely confined to the Northern Hemisphere, and they inhabited warm-temperate and temperate climates under humid conditions. The oldest possible records of the group are ovulate cones from the Late Permian of Italy, but the group is primarily known from the Late Triassic onwards, and were abundant during the Jurassic and Early Cretaceous. Only a handful of species are known from the Late Cretaceous, confined to the northern Russian Far East, corresponding to the decline of other seed plant groups during the explosive radiation of flowering plants. The affinites of Czekanowskiales to other seed plants are obscure. A close relationship to the Ginkgoales has been proposed, based on similar preserved molecular signatures of fossil cuticles, with some authors placing Ginkgoales and Czekanowskiales into the broader grouping Ginkgophyta.
This paleobotany list records new fossil plant taxa that were to be described during the year 2012, as well as notes other significant paleobotany discoveries and events which occurred during 2012.
Weltrichia is a genus belonging to the extinct seed plant group Bennettitales. It is a form genus representing flower-like male pollen-producing organs. It is associated with the female ovulate cone Williamsonia.
Komlopteris is an extinct genus of "seed fern" with possible corystosperm affinities. Fossils have been found across both hemispheres, dating from the latest Triassic to the early Eocene (Ypresian), making it the youngest "seed fern" in the fossil record.
This paleobotany list records new fossil plant taxa that were to be described during the year 2024, as well as notes other significant paleobotany discoveries and events which occurred during 2024.