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Yarravia
''Yarravia'' is a genus of extinct vascular plants mainly known from fossils found in Victoria, Australia. Originally the rocks in which they were found were considered to be late Silurian in age; more recently they have been found to be Early Devonian (Pragian, around ). Specimens consist only of incomplete leafless stems, some of which bore groups of spore-forming organs or sporangia which were fused, at least at the base. Source of fossils Fossils of ''Yarravia'' were found at a location called the 'Yarra Track', near to the town of Wood's Point, Victoria, Australia. The shale in which they were found, now called the Wilson Creek Shale, was for many years regarded as of late Silurian age. The dating was based on graptolite fossils which were identified as ''Monograptus uncinatus'', which is of early Ludlow age (around ). These were subsequently described as a new species, ''M. thomasi'', which proved to be of Early Devonian age (Pragian, around ). Rocks of Silurian age d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hedeia
''Hedeia'' is a genus of early land plants of uncertain affinity. It comprises erect axes terminating in corymbose clusters of erect sporangia. The type species, ''H. corymbosa'', was first described by Isabel Cookson from a few specimens in fine sandstone from near Alexandra, Victoria, Australia. She gave no derivation of the generic name. At the time, the locality was regarded as being of Silurian age, but it is now known to be Early Devonian. It is claimed that an undescribed species, also from Victoria, extends from the Early Devonian back to the Late Silurian. ''H. parvula'' from Kazakhstan and ''H. sinica'' from China are also of Early Devonian age. It is sometimes suggested that ''Hedeia'' and ''Yarravia ''Yarravia'' is a genus of extinct vascular plants mainly known from fossils found in Victoria, Australia. Originally the rocks in which they were found were considered to be late Silurian in age; more recently they have been found to be Early ...'' are merely diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graptolite
Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through the Lower Carboniferous ( Mississippian). A possible early graptolite, ''Chaunograptus'', is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch ''Rhabdopleura'' represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and ''Rhabdopleura'' share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to ''Rhabdopleura''. Due to their widespread abundance, plantkonic l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhyniophyte
The rhyniophytes are a group of extinct early vascular plants that are considered to be similar to the genus '' Rhynia'', found in the Early Devonian (around ). Sources vary in the name and rank used for this group, some treating it as the class Rhyniopsida, others as the subdivision Rhyniophytina or the division Rhyniophyta. The first definition of the group, under the name Rhyniophytina, was by Banks, since when there have been many redefinitions, including by Banks himself. "As a result, the Rhyniophytina have slowly dissolved into a heterogeneous collection of plants ... the group contains only one species on which all authors agree: the type species ''Rhynia gwynne-vaughanii''". When defined very broadly, the group consists of plants with dichotomously branched, naked aerial axes ("stems") with terminal spore-bearing structures (sporangia). The rhyniophytes are considered to be stem group tracheophytes (vascular plants). Definitions The group was described as a subdivisio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebreuve-Ranchicourt
Rebreuve-Ranchicourt is a commune in the Pas-de-Calais department in the Hauts-de-France region of France. Geography Rebreuve-Ranchicourt is situated about southwest of Béthune and southwest of Lille, at the junction of the D341 (an old Roman road, the Chaussée Brunehaut) and the D57 road. The commune was created in 1971 by the joining of the former communes Rebreuve-sous-les-Monts and Ranchicourt. Population Places of interest * The church of Notre-Dame, dating from the nineteenth century. * An eighteenth-century manorhouse. * The church of St.Pierre, dating from the fifteenth century. * The nineteenth-century château de Ranchicourt with an older dovecote and other outbuildings. See also *Communes of the Pas-de-Calais department The following is a list of the 890 communes of the Pas-de-Calais department of France. The communes cooperate in the following intercommunalities (as of 2020): [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baragwanathia
''Baragwanathia'' is a genus of extinct lycopsid plants of Late Silurian to Early Devonian age (), fossils of which have been found in Australia, Canada, China and Czechia. The name derives from William Baragwanath who discovered the first specimens of the type species, ''Baragwanathia longifolia'', at Thomson River (Victoria, Australia). Description ''Baragwanathia'' differed from such taxa as '' Asteroxylon'' by the presence of vascular tissue in its leaves—''Asteroxylon'' had enations without vascular tissue. The sporangia were borne in the axils of the leaves, which were spirally arranged. By comparison, the closely related genus '' Drepanophycus'' of the same period (see Drepanophycaceae for more details) bore its sporangia on the upper surface of specialized leaves known as sporophylls. ''Baragwanathia'' varied in size, with stems up to a few cm in diameter and up to a few metres in length. They were erect or arched, dichotomized (forked) occasionally, and had advent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began domina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludlow
Ludlow () is a market town in Shropshire, England. The town is significant in the history of the Welsh Marches and in relation to Wales. It is located south of Shrewsbury and north of Hereford, on the A49 road (Great Britain), A49 road which bypasses the town. The town is near the confluence of the rivers River Corve, Corve and River Teme, Teme. The oldest part is the medieval Defensive wall, walled town, founded in the late 11th century after the Norman Conquest, Norman conquest of England. It is centred on a small hill which lies on the eastern bank of a bend of the River Teme. Situated on this hill are Ludlow Castle and the parish church, St Laurence's Church, Ludlow, St Laurence's, the largest in the county. From there the streets slope downward to the rivers River Corve, Corve and River Teme, Teme, to the north and south respectively. The town is in a sheltered spot beneath Mortimer Forest and the Clee Hills, which are clearly visible from the town. Ludlow has nearly 500 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monograptus
''Monograptus'' is a genus of graptolites in the Order Graptoloidea. This particular genus is the last stage of the graptoloid evolution before its extinction in the early Devonian. A characteristic of the genus includes one uniserial stipes with very elaborate thecae. This particular genus contains large number of graptolite species and may not be monophyletic. Biostratigraphic significance The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum (FAD) of ''Monograptus uniformis'' as the defining biological marker for the start of the Lochkovian, 419.2 ± 3.2 million years ago, the earliest stage of the Devonian. page 5. Retrieved 2015-06-16. ICS has assigned the FAD of ''Monograptus parultimus'' defining biological marker for the start of the < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woods Point, Victoria
Woods Point is a small town in Victoria, Australia and is located on the banks of the Goulburn River. At the , Woods Point and the surrounding area had a population of 37, down from 94 in 2006. History The town began as a general store built by Henry Wood, to service the gold diggings around the recently discovered Morning Star Reef. Wood's Point Post Office opened on 1 December 1862. By 1864, only three years after the discovery of the gold reef, the area had become a thriving town with 36 hotels. The town was subdivided into numerous suburbs, such as Waverly, Piccadilly, Killarney, Richmond, and Morning Star Hill. Communication was established via a telegraph line to Jamieson, and two local papers were in circulation. From the 1870s to 1890s, mining activity declined, and the population dropped to between 100 and 200. The mining industry was revived in the 1890s, and the population grew once again, with four hotels servicing the town. Much of the town had to be rebuilt fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
