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2021 In Paleobotany
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. Ferns and fern allies Bennettitales Cycadales Ginkgoales Vladimariales Conifers Araucariaceae Cheirolepidiaceae Cupressaceae Pinaceae Podocarpaceae Other conifers Flowering plants Basal angiosperms Unplaced non-eudicots Magnoliids Canellales Monocots Alismatid monocots Lilioid monocots Commelinid monocots =Commelinid monocot research= * A study on the evolutionary history of palms throughout the Cenozoic era, aiming to determine the impact of Cenozoic environmental changes on the diversification and biogeography of palms, is published by Lim ''et al.'' (2021). * Pollens of member of the family Poaceae preserving the same morphological characteristics as that of modern cereal grains are described from a sedimentary core from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennstaedtia
''Dennstaedtia'' is a mostly tropical and subtropical genus of ferns described as a genus in 1801. Hayscented fern, or Cup ferns, are common names for some species in this genus. Its best-known member is probably the temperate North-American hay-scented fern, ''Dennstaedtia punctilobula'' (pictured in the taxobox), which forms extensive clonal ground-cover colonies on level surfaces in the Appalachian area. Some characteristics of Dennstaedtia:"Fronds homomorphic; stipe grooved above, hairy when young... lamina triangular to oblong, many times pinnate, usually densely hairy, especially on rachis... Veins free, pinnately branching, veinlet not reaching margin, with '' hydathode'' at apex. Sori orbicular, marginal, terminal on each veinlet, separate..." File:司氏碗蕨 Dennstaedtia smithii 20220716183935 02.jpg, Groove on the stipe.'' D. smithii'', with a vertical white line on either side of the groove. File:司氏碗蕨 Dennstaedtia smithii 20220716183935 05.jpg, Sori and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klondike Mountain Formation
The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation, named for the type location designated in 1962, Klondike Mountain north of Republic, Washington, is composed of volcanic rocks in the upper unit and volcanics plus lacustrine (lakebed) sedimentation in which a lagerstätte with exceptionally well-preserved plant and insect fossils has been found, along with fossil epithermal hot springs. The formation is the youngest in a group of formations which belong to the Challis Sequence rocks. The formation unconformably overlies rocks of the Eocene Sanpoil Volcanics and much older Triassic and Permian formations. The formation is bounded on its edges by a series of high-angle strike slip faults, which have contained the Klondike Mountain Formation in a series of graben structures, such as the Republic Graben. Public access to a fossiliferous outcrop at the north end of Republic i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennstaedtia Christophelii
''Dennstaedtia'' is a mostly tropical and subtropical genus of ferns described as a genus in 1801. Hayscented fern, or Cup ferns, are common names for some species in this genus. Its best-known member is probably the temperate North-American hay-scented fern, ''Dennstaedtia punctilobula'' (pictured in the taxobox), which forms extensive clonal ground-cover colonies on level surfaces in the Appalachian area. Some characteristics of Dennstaedtia:"Fronds homomorphic; stipe grooved above, hairy when young... lamina triangular to oblong, many times pinnate, usually densely hairy, especially on rachis... Veins free, pinnately branching, veinlet not reaching margin, with '' hydathode'' at apex. Sori orbicular, marginal, terminal on each veinlet, separate..." File:司氏碗蕨 Dennstaedtia smithii 20220716183935 02.jpg, Groove on the stipe.'' D. smithii'', with a vertical white line on either side of the groove. File:司氏碗蕨 Dennstaedtia smithii 20220716183935 05.jpg, Sori and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claytosmunda
''Claytosmunda'' is a genus of fern. It has only one extant species, ''Claytosmunda claytoniana'' (synonym ''Osmunda claytoniana''), the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada. The specific epithet is named after the English-born Virginian botanist John Clayton. "Interrupted" describes the gap in middle of the blade left by the fertile portions after they wither and eventually fall off. The plant is known from fossils to have grown in Europe, showing a previous circumboreal distribution. Fragmentary foliage resembling ''Claytosmunda'' has been found in the fossil record as far back as the Triassic. Description ''Claytosmunda claytoniana'' fronds are bipinnate, tall and broad, the blade formed of alternate segments forming an arching blade tightening to a pointed end. The lower end is also slightly thinner than the rest of the frond because the first segments are shorter. Three to seven short, cinnamon-colored fertile segments are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiaojishan Formation
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation (also known as the Jiulongshan Formation) as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation. Age Using Argon–argon dating, Wang and colleagues in 2005 dated part of the Tiaojishan Formation to about 160 million years ago, the beginning of the Oxfordian stage, the first stage of the Upper Jurassic epoch. In 2006, a study by Liu and colleagues used U-Pb zircon dating to conclude that the Tiaojishan Formation correlates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow. Life forms of the epoch This epoch is well known for many famous types of din ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claytosmunda Zhangii
''Claytosmunda'' is a genus of fern. It has only one extant species, ''Claytosmunda claytoniana'' (synonym ''Osmunda claytoniana''), the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada. The specific epithet is named after the English-born Virginian botanist John Clayton. "Interrupted" describes the gap in middle of the blade left by the fertile portions after they wither and eventually fall off. The plant is known from fossils to have grown in Europe, showing a previous circumboreal distribution. Fragmentary foliage resembling ''Claytosmunda'' has been found in the fossil record as far back as the Triassic. Description ''Claytosmunda claytoniana'' fronds are bipinnate, tall and broad, the blade formed of alternate segments forming an arching blade tightening to a pointed end. The lower end is also slightly thinner than the rest of the frond because the first segments are shorter. Three to seven short, cinnamon-colored fertile seg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennstaedtiaceae
Dennstaedtiaceae is one of fifteen families in the order Polypodiales, the most derived families within monilophytes (ferns). It comprises 10 genera with ca 240 known species, including one of the world's most abundant ferns, ''Pteridium aquilinum'' (bracken). Members of the order generally have large, highly divided leaves and have either small, round intramarginal sori with cup-shaped indusia (e.g. ''Dennstaedtia'') or linear marginal sori with a false indusium formed from the reflexed leaf margin (e.g. ''Pteridium''). The morphological diversity among members of the order has confused past taxonomy, but recent molecular studies have supported the monophyly of the order and the family.Smith, A. R., K. M. Pryer, et al. (2006). "A classification for extant ferns." Taxon 55(3): 705-731 The reclassification of Dennstaedtiaceae and the rest of the monilophytes was published in 2006, so most of the available literature is not updated. Characteristics * Terrestrial or scrambling (sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
