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Amisan Formation
The Amisan Formation () is an Late Triassic geologic Formation (geology), formation in South Korea. Fossil records from this formation include plants, insects, and fish remains. Geology The Amisan Formation in the Chungnam Basin overlies the Hajo Formation and underlies the Jogyeri Formation. It is subdivided into five zones based on its lithology, lower sandstone, lower shale, middle sandstone, middle shale, and upper sandstone zones. Depositional environments of the lower and middle shale zones of the Amisan Formation are thought to be lacustrine settings. The depositional age of the Nampo Group including the Amisan Formation is debated, but plant genera ''Lobatannularia'' and ''Sphenophyllum'' from the Baegunsa Formation, which overlies the Amisan Formation and the Jogyeri Formation suggests that the Upper Triassic spans to the Baegunsa Formation. Also, conchostracan fossils and some insect fossils support the Triassic origin of the Amisan Formation. Fossil content Most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for fungi, it is ''funga''. Sometimes bacteria and fungi are also referred to as flora as in the terms ''gut flora'' or ''skin flora''. Etymology The word "flora" comes from the Latin name of Flora (mythology), Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic compos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podozamites
''Podozamites'' is an extinct genus of fossil conifer leaves. In its broader sense, it has been used as a morphogenus ( form taxon) to refer to any broad leaved multi-veined conifer leaves. Modern broad-leaved conifers with a similar form include ''Agathis'' in the family Araucariaceae and '' Nageia'' in Podocarpaceae, with some ''Podozamites'' ''sensu lato'' probably belonging to the same families. In a more narrow sense, ''Podozamites'' has been used to refer to the leaves of a probably monophyletic group of deciduous broad leafed voltzialean conifers which lived in the Northern Hemisphere, particularly East Asia and Siberia, during the Late Triassic to early Late Cretaceous, where it formed part of wet coal swamp communities. Description In the right conditions, ''Podozamites'' leaves ''sensu stricto'' preserve delicate cuticle and insect damage, and are thought to have been regularly shed. They are associated with conifer cones of the genera '' Swedenborgia, Cycadocarpi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperm
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνόσπερμος ( el, γυμνός, translit=gymnos, lit=naked, label=none and el, σπέρμα, translit=sperma, lit=seed, label=none), literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or solitary as in yew, ''Torreya'', '' Ginkgo''. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploid sporophyte phase and a reduced haploid gametophyte phase which is dependen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterophyllum (plant)
''Pterophyllum'' is an extinct form genus of leaves known from the Carnian to the Maastrichtian, belonging to the Bennettitales (family Williamsoniaceae). It contains more than 50 species, and is mainly found in Eurasia and North America. Description ''Pterophyllum'' are characterized by their completely segmented leaves, with slender leaflets more than twice as long as they are high. The leaflets are regularly spaced, arranged opposite to each other, and have nearly parallel edges, only slightly broader at their bases and narrower at their tips. They are covered with fine longitudinal veins with minor bifurcation. The leaflets slightly lengthen towards the middle of the leaf and shrink towards its tip, for an overall lanceolate (long and tapered) or oblong shape to the leaf. At the tip of the leaf sits a terminal leaflet which can vary in shape from the rest. Like other bennettitaleans, the leaf's cuticle was syndetocheilic (with guard and subsidiary cells of the stomata h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bennettitales
Bennettitales (also known as cycadeoids) 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 are among the most common Mesozoic seed plants, 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. Although certainly gymnosperms (cone-bearing seed plants), the relationships of bennettitaleans to other seed plants is debated. Their general resemblance to cycads is contradicted by numerous more subtle features of their reproductive systems and leaf structure. Some authors have linked bennettitaleans to angiosperms (flowering plants) and gnetophytes (a rare and unusual group of modern gymnosperms), forming a broader group known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetites
Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which comprises about twenty species. Evolution and systematics Equisetaceae is the only surviving family of the Equisetales, a group with many fossils of large tree-like plants that possessed ribbed stems similar to modern horsetails. ''Pseudobornia'' is the oldest known relative of ''Equisetum''; it grew in the late Devonian, about 375 million years ago and is assigned to its own order. All living horsetails are placed in the genus ''Equisetum''. But there are some fossil species that are not assignable to the modern genus. ''Equisetites'' is a "wastebin taxon" uniting all sorts of large horsetails from the Mesozoic; it is almost certainly paraphyletic and would probably warrant being subsumed in ''Equisetum''. But while some of the species placed there are likely to be ancestral to the modern horsetails, there have been reports of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiropteris
''Chiropteris'' is an extinct genus of plants that existed from the Early Permian (Sakmarian stage) to the Late Jurassic (?Oxfordian stage, maybe latter). It is unknown whether it belongs in the Matoniaceae or the Dipteridaceae. Description The genus ''Chiropteris'' was named from fragmentary and whole-plant fossils. It was constituted of a short 25cm long petiole and a 16cm diameter circular leaf. Location In Brazil, fossil of genus ''Chiropteris'', was located on outcrop in the municipalities of São Jerônimo and Mariana Pimentel. They are in the geopark Paleorrota in Rio Bonito Formation and date from Sakmarian in Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Pale .... References Ginkgophyta Prehistoric plant genera Permian plants Triassic plants Permian first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladophlebis
''Cladophlebis'' is an extinct form genus of fern, used to refer to Paleozoic and Mesozoic fern leaves that have "fern fronds with pinnules that are attached to the rachis, and have a median vein that runs to the apex of the pinnule, and veins from that are curved and dichotomise". By convention this genus is not used to refer to fossil ferns from the Cenozoic. Ferns with this morphology belong to several families, including Osmundaceae, Dicksoniaceae and Schizaeaceae. Ferns with this morphology are common during the Paleozoic and Mesozoic in both the northern and southern hemispheres.''Cladophlebis'' at .org Species There were many species ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
