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Mizur Formation
The Mizur Formation is a geological formation that outcrops in North Ossetia–Alania in the North Caucasus, representing a series of marginal marine to coastal layers with terrestrial influence. It is of Late Pliensbachian (Lower Jurassic) age. It is notable as the only major unit with preserved dinosaur footprints of various orders not yet ascribed to any concrete Ichnotaxon, ichnogenus. Stratigraphy Fytyn Member The Fytyn member represent the older layers of the formation, and depending on the outcrop, it overlies the eroded surface of Paleozoic granites or crystalline schists, or the Sinemurian–lower Pliensbachian volcanosedimentary rocks of the Sadon Formation. This member is composed mostly of the product of the regional erosion of older layers — conglomerates, gravelstones, quartz sandstones, and others — that were deposited in a mostly continental setting. It is up to a few dozen meters thick. Faraskat Member In some outcrops the Fytyn Member is absent, as result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ardon River
The Ardon (russian: Ардон, os, Ӕрыдон, ''Ærydon'') is a river in North Ossetia–Alania in Russia, a left tributary of the Terek. It flows north and somewhat east to join the Terek northwest of Vladakavkaz. Its main tributary is the which parallels it on the east and joins it near its mouth. The length of the Ardon is 102 km, the area of its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioturbation
Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a primary driver of biodiversity. The formal study of bioturbation began in the 1800s by Charles Darwin experimenting in his garden. The disruption of aquatic sediments and terrestrial soils through bioturbating activities provides significant ecosystem services. These include the alteration of nutrients in aquatic sediment and overlying water, shelter to other species in the form of burrows in terrestrial and water ecosystems, and soil production on land.Shaler, N. S., 1891, The origin and nature of soils, in Powell, J. W., ed., USGS 12th Annual report 1890-1891: Washington, D.C., Government Printing Office, p. 213-45. Bioturbators are deemed ecosystem engineers because they alter resource availability to other species through the physical ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically-oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachiopods, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnitida
Belemnitida (or the belemnite) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an internal skeleton that made up the cone. The parts are, from the arms-most to the tip: the tongue-shaped pro-ostracum, the conical phragmocone, and the pointy guard. The calcitic guard is the most common belemnite remain. Belemnites, in life, are thought to have had 10 hooked arms and a pair of fins on the guard. The chitinous hooks were usually no bigger than , though a belemnite could have had between 100 and 800 hooks in total, using them to stab and hold onto prey. Belemnites were an important food source for many Mesozoic marine creatures, both the adults and the planktonic juveniles, and likely played an important role in restructuring marine ecosystems after the Triassic–Jurassic extinction event. They may have laid between 100 and 1,000 eggs. Some species may have been adapted to speed and swam in the tur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocalamites
''Neocalamites'' is an extinct genus of Equisetales, equisetalean plant. ''Neocalamites'' thrived during the Permian and Triassic, and occurs worldwide. Description According to Elgorriaga et al. 2018, characteristics of ''Neocalamites'' include: "(1) aerial stems with continuous ribs across nodes, (2) Whorl (botany), whorls of unfused leaves as in archaeocalamitacean plants, (3) compact Strobilus, strobili consisting of successive whorls of peltate sporangiophores, and (4) bearing six or more sporangia per sporangiophore as in equisetacean strobili." The leaves are similar to those of ''Annularia'' while the stems closely resemble those of ''Calamites''. It is disputed as to whether members of the genus have secondary xylem. ''Neocalamites'' is suggested to have had a Herbaceous plant, herbaceous to shrub like habit. It is suggested to have grown in wet habitats, such as on the banks of rivers. Taxonomy Recent phylogenetic analysis has placed the genus as more closely related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selaginella
''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. They are sometimes included in an informal paraphyletic group called the "fern allies". '' S. moellendorffii'' is an important model organism. Its genome has been sequenced by the United States Department of Energy's Joint Genome Institute. The name ''Selaginella'' was erected by Palisot de Beauvois solely for the species ''Selaginella selaginoides'', which turns out (with the closely related ''Selaginella deflexa'') to be a clade that is sister to all other ''Selaginellas'', so any definitive subdivision of the species into separate genera leaves two taxa in ''Selaginella'', with the hundreds of other species in new or resurrected genera. ''Selaginella'' occurs mostly in the tropical regions of the world, with a hand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coniopteris
''Coniopteris'' is an extinct genus of Mesozoic fern leaves with a fossil range from the Early Jurassic to the Cenomanian stage of the Late Cretaceous. 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 The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas. Description Polypodiale .... Most species of ''Coniopteris'' probably had a herbaceous habit. The genus is technically a junior synonym of the little used ''Polystichites,'' but was conserved by the ICZN in 2013. References † Prehistoric plant genera Early Triassic genus first appearances Cenoma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgoaceae
The Ginkgoaceae is a family of gymnosperms which appeared during the Mesozoic Era, of which the only extant representative is ''Ginkgo biloba'', which is for this reason sometimes regarded as a living fossil A living fossil is an extant taxon that cosmetically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossi .... Formerly, however, there were several other genera, and forests of ginkgo existed. Because leaves can take such diverse forms within a single species, these are a poor measure of diversity, although differing structures of wood point to the existence of diverse ginkgo forests in ancient times. References External links * * * * . Plant families Jurassic plants Extant Jurassic first appearances {{Tree-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araucariaceae
Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost worldwide. Most of the Araucariaceae in the Northern Hemisphere vanished in the Cretaceous–Paleogene extinction event, and they are now largely confined to the Southern Hemisphere, except for a few species of ''Agathis'' in Southeast Asia. Description Members of Araucariaceae are typically extremely tall evergreen trees, reaching heights of or more. They can also grow very large stem diameters; a New Zealand kauri tree (''Agathis australis'') named ''Tāne Mahuta'' ("The Lord of the Forest") has been measured at tall with a diameter at breast height of . Its total wood volume is calculated to be , making it the third-largest conifer after '' Sequoia'' and ''Sequoiadendron'' (both from the Cupressaceae subfamily Sequoioideae). The trunks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podocarpaceae
Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs.James E. Eckenwalder. 2009. ''Conifers of the World''. Portland, Oregon: Timber Press. . It contains 19 genera if ''Phyllocladus'' is included and ''Manoao'' and ''Sundacarpus'' are recognized. The family is a classic member of the Antarctic flora, with its main centres of diversity in Australasia, particularly New Caledonia, Tasmania, and New Zealand, and to a slightly lesser extent Malesia and South America (primarily in the Andes Mountains). Several genera extend north of the equator into Indochina and the Philippines. ''Podocarpus'' reaches as far north as southern Japan and southern China in Asia, and Mexico in the Americas, and ''Nageia'' into southern China and southern India. Two genera also occur in sub-Saharan Africa, the widespread ''Podocarpus'' and the endemic '' Afrocarpus''. ''Parasitaxus usta'' is uniqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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