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Avalon Assemblage
The Avalon assemblage was the first of the three Late Ediacaran biotic assemblages, spanning from 575 Ma to 560 Ma. It was followed by the White Sea assemblage, although temporal overlaps have been noted between the biotic assemblages. While earlier macroscopic fossils, mostly of algal origin, are known from the Lantian Formation, Avalon-type localities provide some of the first evidence of putative metazoan ancestors, as part of the Ediacaran biota. Research history The division of the Ediacaran biota in three separate assemblages was first postulated by Ben Waggoner in 2003. Geography Most Avalonian fossil sites are known from the central United Kingdom and eastern Newfoundland, historically connected as part of the Avalonia microcontinent. Outside of Avalonia proper, other sites have been identified as part of the Avalon assemblage, such as the Olenek Uplift in Siberia, and Sekwi Brooke in the Northwest Territories of Canada. Biota Deep-water rangeomorphs, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frondose
Frondosity (from Latin ''frondōsus'' meaning 'leafy') is the property of an organism that normally flourishes with fronds or leaf-like structures. Many frondose organisms are thalloid and lack the organization of tissues into organs, with the exception of ferns. Frondosity is significant mainly for distinguishing particular types of Seaweed, macroscopic algae, and in paleobotany and paleontology, by analyzing features present in fossil biota. Frondose macroalgae are relevant to the ecology of many marine and coastal ecosystems. Large frondose algae play an important role in the creation and functioning of healthy ecosystems from kelp forests to similar habitats. Yet, in coral reefs, frondose seaweed can be recognized as harmful due to the link between Algal bloom, excessive blooms and coastal eutrophication. Ediacaran biota The Taphonomy, fossil record from the Ediacaran, Ediacaran Period is sparse, as more easily fossilized hard-shelled animals had yet to evolve. Most fos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avalonia
Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent are terranes in parts of the eastern coast of North America: Atlantic Canada, and parts of the East Coast of the United States, East Coast of the United States. In addition, terranes derived from Avalonia also make up portions of Northwestern Europe, being found in England, Wales and parts of Ireland. Avalonia developed as a volcanic arc on the northern margin of Gondwana. It eventually rifted off, becoming a drifting microcontinent. The Rheic Ocean formed behind it, and the Iapetus Ocean shrank in front. It collided with the continents Baltica, then Laurentia. The Armorican terrane, Armorican Terrane assemblage collided with the merged Baltica/Avalonia during the formation of Pangea. When Pangea broke up, Avalonia's remains were divided by the rift which became the Atlantic Ocean. Avalonia is named for the Avalon Peninsula in Newfoundland (island), Newfoundland. When the term "A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboreomorph
The arboreomorphs (Arboreomorpha) are ediacaran organisms of the frondomorph type that had a disk or bulb-shaped anchor on the ocean floor, a central stem and branching. The "branches" were smooth, tubular structures, often swollen with bifurcation and connected together to form a leaf-like structure.Marc Laflamme & Guy M. Narbonne (2008): Competition in a Precambrian world: palaeoecology of Ediacaran fronds. Geology Today Vol. 24, No. 5: 182-187. It was previously included within Rangeomorpha The rangeomorphs are a group of Ediacaran fossils. Ediacarans are the oldest large fossil organisms on earth, and many are not self-evidently related to anything else that has ever lived. However, some Ediacarans clearly resemble each other. Pale ..., but later removed when more related forms were found. References Petalonamae Ediacaran life Prehistoric marine animals {{Ediacaran-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rangeomorph
The rangeomorphs are a group of Ediacaran Ediacaran biota, fossils. Ediacarans are the oldest large fossil organisms on earth, and many are not self-evidently related to anything else that has ever lived. However, some Ediacarans clearly resemble each other. Palentologists have not been able to agree on what else, if anything, is related to these organisms, so Ediacarans are usually classified into groups based on their appearance. These "Form taxon, form taxa" allow scientists to study and discuss Ediacarans when they cannot know what kind of living things they were, or how they were genetically related to each other. Rangeomorphs look roughly like fern fronds or feathers arranged around a central axis; the group is defined as Ediacarans with a similar appearance and structure to the genus ''Rangea''. Some researchers, such as Pflug and Narbonne, believe all rangeomorphs were more closely related to each other than to anything else. If true, this would make the group a natural tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northwest Territories
The Northwest Territories is a federal Provinces and territories of Canada, territory of Canada. At a land area of approximately and a 2021 census population of 41,070, it is the second-largest and the most populous of Provinces and territories of Canada#Territories, the three territories in Northern Canada. Its estimated population as of the first quarter of 2025 is 45,074. Yellowknife is the capital, most populous community, and the only city in the territory; its population was 20,340 as of the 2021 census. It became the territorial capital in 1967, following recommendations by the Carrothers Commission. The Northwest Territories, a portion of the old North-Western Territory, entered the Canadian Confederation on July 15, 1870. At first, it was named the North-West Territories. The name was changed to the present Northwest Territories in 1906. Since 1870, the territory has been divided four times to create new provinces and territories or enlarge existing ones. Its current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberia
Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states since the lengthy conquest of Siberia, which began with the fall of the Khanate of Sibir in 1582 and concluded with the annexation of Chukotka in 1778. Siberia is vast and sparsely populated, covering an area of over , but home to roughly a quarter of Russia's population. Novosibirsk, Krasnoyarsk, and Omsk are the largest cities in the area. Because Siberia is a geographic and historic concept and not a political entity, there is no single precise definition of its territorial borders. Traditionally, Siberia spans the entire expanse of land from the Ural Mountains to the Pacific Ocean, with the Ural River usually forming the southernmost portion of its western boundary, and includes most of the drainage basin of the Arctic Ocean. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olenek Uplift
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Olenyok or Olenek may refer to: *Olenyok (river), a river in Russia *Olenyok (rural locality), a rural locality (a ''selo'') in the Sakha Republic, Russia *Olenyok Airport, an airport in the same rural locality *Olenyok Gulf, a gulf in the Laptev Sea See also * Olenyoksky District Olenyoksky District (; , ''Ölöön uluuha'', ), or Olenyoksky-Evenki National District, is an administrativeConstitution of the Sakha Republic and municipalLaw #172-Z #351-III district (raion, or ''ulus''), one of the thirty-four in the Sakha Rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacaran Biota
The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The term "Ediacara biota" has received criticism from some scientists due to its alleged inconsistency, arbitrary exclusion of certain fossils, and inability to be precisely defined. The Ediacaran biota may have undergone evolutionary radiation in a proposed event called the Avalon explosion, . This was after the Earth had thawed from the Cryogenian period's extensive glaciation. This biota largely disappeared with the rapid increase in biodiversity known as the Cambrian explosion. Most of the currently existing body plans of animals first appeared in the fossil record of the Cambrian rather than the Ediacara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mistaken Point
Mistaken Point Ecological Reserve is a wilderness area and a UNESCO World Heritage Site located at the southeastern tip of Newfoundland's Avalon Peninsula in the Canadian province of Newfoundland and Labrador. The reserve is home to the namesake Mistaken Point Formation, which contains one of the most diverse and well-preserved collections of Precambrian fossils in the world. Ediacaran fossils discovered at the site constitute the oldest known remnants of multicellular life on Earth. Mistaken Point Mistaken Point () is a small headland on the Avalon Peninsula. Historically, Mistaken Point has been mistaken for Cape Race due to the area's typically foggy weather conditions. Sailors making this error would turn north, thinking they had reached Cape Race Harbour, and immediately run into treacherous rocks. History The first fossil to be found in the area, '' Fractofusus misrai'', was discovered in June 1967 by Shiva Balak Misra, an Indian graduate student studying geology at Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
