Zamites | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Order: | † Bennettitales |
Family: | † Williamsoniaceae |
Genus: | † Zamites Brongniart, 1828 |
Species | |
See text |
Zamites is a genus of sterile foliage known from the Mesozoic of North America, Europe, India and Antarctica through the Eocene of North America. It was erected as a form taxon for leaves that superficially resembled the extant cycad Zamia , however it is now believed to belong to a similar but phylogenetically different group, the cyacadeoids (Bennettitales). [1] The fronds are linear or lanceolate in shape, and pinnately compound, with pinnae with parallel veins and smooth margins, and symmetrical and constricted at the base where they are attached obliquely to the upper surface of the rachis. [2] [3] [4] It has been interpreted as a Bennettitalean plant [5] [6] in the family Williamsoniaceae. [7] It is associated with the ovulate cone Williamsonia and male cone Weltrichia . [8]
As explained by Zijlstra & van Konijnenburg-van Cittert (2020), the application of the genus name Zamites has over time drifted away from Brongniart's original concept to one where the species Z. gigas (Lindl. & Hutton) Morris has been treated as a de facto type, to the degree that none of Brongniart's four original species would now be assigned to it, instead being allocated to Otozamites and possibly elsewhere; this includes Z. bucklandii, designated as the type of Zamites by Pfeiffer in a publication dating from 1871-1875, but now (as O. bucklandii) the type of Otozamites. [1] Technically, unless otherwise addressed, this renders Otozamites a synonym of Zamites and would mean that Z. gigas plus all the species recognisably closer to it than to Z. bucklandii would require a new genus name. Zijlstra & van Konijnenburg-van Cittert chose to attempt to circumvent this situation by proposing that Zamites should be re-defined based on designating Z. gigas as a new type to replace Z. bucklandii, a proposal that was recommended for acceptance by the Nomenclature Committee for Fossils in 2022. [9]
Species include: [5]
Fossils of Zamites have been found in: [6]
Antarctica, Austria, China, France, Germany, Honduras, Hungary, Italy, Japan, Mexico, Romania, Tajikistan, Ukraine, and the United States (New Mexico, North Carolina, Utah, Virginia, Virginia/North Carolina).
Antarctica, Argentina, Azerbaijan, Belarus, Chile, China, Colombia (Valle Alto Formation, Caldas), Egypt, France, Georgia, Germany, Iran, Italy, Japan, Kazakhstan, Mexico, Mongolia, Portugal, Romania, the Russian Federation, Serbia and Montenegro, Switzerland, Tajikistan, Turkey, Ukraine, the United Kingdom, and the United States (Montana, Wyoming).
Canada (Alberta, British Columbia), Ecuador, Japan, Mexico, South Africa, Spain, and the United States (Montana, Virginia, Wyoming).
United States (California)
Anina is a town in the Banat region of Romania, in Caraș-Severin County, with a population of 5,521 in 2021. The town administers one village, Steierdorf.
Bennettitales is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales were amongst the most common seed plants of the Mesozoic, and had morphologies including shrub and cycad-like forms. The foliage of bennettitaleans is superficially nearly indistinguishable from that of cycads, but they are distinguished from cycads by their more complex flower-like reproductive organs, at least some of which were likely pollinated by insects.
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.
Sagenopteris is a genus of extinct seed ferns from the Triassic to late Early Cretaceous.
Pachypteris is a Mesozoic pteridosperm genus of fossil leaves. It has either been aligned with the peltasperms or the corystosperms.
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Cunninghamites elegans is an extinct conifer species in the family Cupressaceae and the genus Cunninghamites.
Agathoxylon is a form genus of fossil wood, including massive tree trunks. Although identified from the late Palaeozoic to the end of the Mesozoic, Agathoxylon is common from the Carboniferous to Triassic. Agathoxylon represents the wood of multiple conifer groups, including both Araucariaceae and Cheirolepidiaceae, with late Paleozoic and Triassic forms possibly representing other conifers or other seed plant groups like "pteridosperms".
Nilssonia is a genus of fossil foliage traditionally assigned to the Cycadophyta either in Cycadales or their own order Nilssoniales, though the relationships of this genus with the Cycadales have been put into question on chemical grounds.
Pterotrigonia is an extinct genus of saltwater clams, marine bivalve molluscs in the family Megatrigoniidae. This genus is known in the fossil record from the Jurassic period Tithonian age to the Cretaceous period Maastrichtian age. Species in this genus were facultatively mobile infaunal suspension feeders. The type species of the genus is Pterotrigonia cristata.
Coniopteris is an extinct genus of Mesozoic fern leaves. It was widespread over both hemispheres during the Jurassic and Early Cretaceous, with over 130 species having been described. While traditionally assumed to have been a member of Dicksoniaceae or a close relative of Thyrsopteris, a 2020 cladistic analysis found it to be a stem group of Polypodiales. Most species of Coniopteris probably had a herbaceous habit. Coniopteris laciniata had tufts of leaves sprouting from intervals of a thin, creeping rhizome. The genus is technically a junior synonym of the little used Polystichites, but was conserved by the ICZN in 2013. Some authors suggest a range of Early Jurassic-early Late Cretaceous for the genus, while others suggest a more expansive range spanning from the Middle Triassic to the Eocene.
Pterophyllum is an extinct form genus of leaves known from the Carnian to the Maastrichtian, belonging to the Bennettitales. It contains more than 50 species, and is mainly found in Eurasia and North America.
This article records new taxa of fossil plants that are scheduled to be described during the year 2021, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2021.
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Araucarites is an extinct genus of conifer, used to refer to female conifer cones that resemble those of the family Araucariaceae. Species assigned to the genus lived in the Permian to Eocene and have been found worldwide.
Otozamites is an extinct form genus of leaves belonging to the Bennettitales.
Nilssoniopteris is an extinct form genus of leaves belonging to the Bennettitales. Leaves are slender and often entire-margined (smooth-edged), though some species have dissected leaves with numerous small segments extending down to the rachis of the leaf. Nilssoniopteris-like leaves are distinguished by their syndetocheilic stomata, indicating bennettitalean affinities. Similar "taeniopterid" leaves are placed in the genus Nilssonia if their stomata are instead haplocheilic, or Taeniopteris if the cuticle is not preserved. Leaves of Nilssoniopteris vittata from the Middle Jurassic of England are associated with bisexual Williamsoniella reproductive structures.
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.
Taeniopteris is an extinct form genus of Mesozoic vascular plant leaves, perhaps representing those of cycads, bennettitaleans, or marattialean ferns. The form genus is almost certainly a polyphyletic category for unfertile leaves of a certain shape ("taeniopterids") which cannot be assigned to specific groups due to a lack of information on cuticle or spore structures. The leaves are simple, with a strong central vein (rhachis) and an unbroken margin. The central vein leads to nearly perpendicular lateral veins, which may be slightly divided or undivided. The shape of the leaf is variable, but often elongated and smooth-edged. "Taeniopterid" leaves with bennettitalean-type cuticle are placed in the form genus Nilssoniopteris, while those with cycad-type cuticle are placed within Nilssonia and related genera. Some fertile "taeniopterids" preserve spore packages, and can be assigned to marattialean ferns.
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