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List Of Ediacaran Genera
The existence of life, especially that of animals, before the Cambrian had long been the subject of debate in paleontology. The apparent suddenness of the Cambrian explosion had no firm explanation, and Charles Darwin himself recognized the challenge it posed for his theory of evolution. While reports of Precambrian organisms have been made since Alexander Murray's 1868 discovery of ''Aspidella'', it wasn't until the discovery of ''Charnia'' in 1956 that considerable evidence of Precambrian life had been presented. The period immediately preceding the Cambrian, the Ediacaran, is now widely accepted of containing animal life. It spans from 635 to 540 million years ago, and covers approximately 2% of Earth's history. Taxonomists have purported a total of 245 described genera from the Ediacaran, 162 of which are accepted as valid. Key * Valid genus - Genera that are accepted by the scientific community * Synonym (taxonomy), Junior synonym - Alternative name for an already existi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life In The Ediacaran Sea
Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, metabolism, Cell growth, growth, adaptation, response to stimulus (physiology), stimuli, and reproduction. All life over time eventually reaches a state of death, and none is Immortality, immortal. Many philosophical definitions of living systems have been proposed, such as self-organizing systems. Viruses in particular make definition difficult as they replicate only in Host (biology), host cells. Life exists all over the Earth in air, water, and soil, with many ecosystems forming the biosphere. Some of these are harsh environments occupied only by extremophiles. Life has been studied since ancient times, with theories such as Empedocles's materialism asserting that it was composed of Classical element, four eternal elements, and Aristotle's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andiva
''Andiva ivantsovi'' is a Vendian fossil, identified to be a bilaterian triploblastic animal in the Ediacaran phylum Proarticulata, known from the Winter Coast, White Sea, Russia. It was first discovered in 1977, and described as a new species in a new genus by Mikhail Fedonkin in 2002. It lived about 555 million years ago. Fossils of ''Andiva'' also occur in South Australia. All known fossils of ''Andiva'' are external molds. Description ''Andiva'' was between long and from wide, with a bilaterally symmetrical shape, larger on the anterior end and narrower at the posterior. The anterior part features a smooth "fringe" followed by a surface "covered by fine ribs and sutura", also described as a "quilt" with narrow, tightly packed chambers The symmetry of these ribs is a glide symmetry, that is, in which the corresponding segments on the left and right sides do not line up, but are staggered. This is a feature shared by other forms belonging to the proposed taxon Proartic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeocyatha
Archaeocyatha (), 'ancient cups') is a taxon of extinct, Sessility (zoology), sessile, reef-building Marine (ocean), marine Sponge, sponges that lived in warm tropical and subtropical waters during the Cambrian Period. It is believed that the centre of the Archaeocyatha origin is now located in East Siberia, where they are first known from the beginning of the Tommotian Age of the Cambrian, 525 million years ago (mya (unit), mya). In other regions of the world, they appeared much later, during the Atdabanian, and quickly diversified into over a hundred Family (biology), families. They became the planet's first reef-building animals and are an index fossil for the Lower Cambrian worldwide. Preservation The remains of Archaeocyatha are mostly preserved as carbonate structures in a limestone Matrix (geology), matrix. This means that the fossils cannot be chemically or mechanically isolated, save for some specimens that have already eroded out of their matrices, and their morph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porifera
Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a Basal (phylogenetics) , basal clade and a sister taxon of the Eumetazoa , diploblasts. They are sessility (motility) , sessile filter feeders that are bound to the seabed, and are one of the most ancient members of macrobenthos, with many historical species being important sponge reef , reef-building organisms. Sponges are multicellular organisms consisting of jelly-like mesohyl sandwiched between two thin layers of cell (biology) , cells, and usually have tube-like bodies full of pores and channels that allow water to circulate through them. They have unspecialized cells that can cellular differentiation , transform into other types and that often migrate between the main cell layers and the mesohyl in the process. They do not have complex nervous system , nervous, digestive system , digestive or circulatory systems. Instead, most rely on maintaining a constant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arimasia
''Arimasia germsi'' is an extinct sponge from the late Ediacaran, with possible affinities to the Archaeocyatha. Estimated to be about 543 million years old, ''A. germsi'' has been identified as possibly being the oldest known archaeocyathan to date. Its fossil material was found between 1993 and 1996 from the Nama Group in Namibia. Discovery and name The fossil material of ''Arimasia'' was found from the Nama Group of Namibia during the years of 1993, 1995 and 1996, and officially described in 2024. The generic name ''Arimasia'' is derived from Arimas farm, the type locality of the fossil material. The specific name ''germsi'' is derived from the surname of Gerard J.B. Germs, celebrating the 50th anniversary of his Ph.D. dissertation on ''The stratigraphy and paleontology of the lower Nama Group, South West Africa''. Description ''Arimasia germsi'' is possibly the earliest known archaeocyathan sponge, and the only one to be found in the Ediacaran, with possible relations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onegia Nenoxa
''Pteridinium'' is an erniettomorph found in a number of Precambrian deposits worldwide. It is a member of the Ediacaran biota. Body plan The three-lobed body is generally flat such that only two lobes are visible. Each lobe consists of a number of parallel ribs extending back to the main axis where the three lobes come together. Even on well-preserved specimens, there is no sign of a mouth, anus, eyes, legs, antennae, or any other appendages or organs. The organism grew primarily by the addition of new units, probably at both ends, with the inflation of existing units contributing little to its growth. Ecology Specimens found in what is thought to be life positions indicate that the creature rested on, or possibly in, the sediment in shallow seas. No tracks are known that would seem to be consistent with a moving ''Pteridinium''. It is unclear whether it performed photosynthesis, or osmotically extracted nutrients from seawater. Occurrence Fossils are common in late Precambri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeichnium
''Archaeichnium'' is a member of the Ediacaran biota (635-542 Ma) first described by Martin Glaessner in 1963. It is characterized as a tubular fossil found in the Nama group (570-543 Ma) of South West Africa, and is a monotypic genus, containing only ''Archaeichnium haughtoni''. Discovery The rock containing the fossil that would eventually be named ''Archaeichnium haughtoni'' was first discovered in 1927 by Dr. H. F. Frommurze and S. H. Haughton while the two were doing geological mapping in Southwest Africa. The rock was found in the Nama group of Cambrian age in Central/ Southern Namibia. In 1959, Haughton published the paper that described the fossils as early archaeocyathids, a taxon of sedentary reef-building organisms that doesn't usually appear in the fossil record until the late Cambrian. However, in 1963 Martin Glaessner revisited the rocks and determined that the fossilized animals did not actually distinctly possess the features that would classify it as an archaeo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeaspinus
''Archaeaspinus fedonkini'' is an extinct proarticulatan organism from the Late Ediacaran period. Background ''Archaeaspinus'' was discovered in Zimnii Bereg, the Winter Coast of the White Sea in Russia, by A. Yu. Ivantsov in 2001. Since then, numerous additional fossils have been attributed to the genus, mostly from that same type locality, but a small number from Flinders Ranges in South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ... as well. Originally called '' Archaeaspis''—a name already applied to a redlichiid trilobite—in 2001 by Ivantsov, it was later recombined under its current name in 2007 by the same author. The type species, ''A. fedonkini'', is the only species known in this genus. It appears in the fossil record between 571-551Ma. Descrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petalonamae
The petalonamids (Petalonamae) are an extinct group of archaic animals typical of the Ediacaran biota, also called frondomorphs, dating from approximately 635 million years ago to 516 million years ago. They are benthic and motionless animals, that have the shape of leaves, fronds (frondomorphic), feathers or spindles and were initially considered algae, octocorals or sea pens. It is now believed that there are no living descendants of the group, which shares a probable relation to the Ediacaran animals known as Vendozoans. It is commonly conjectured that the organisms were fluffy at least in appearance, as if "inflatable." They are particularly difficult to classify phylogenetically. Lacking mouths, intestines, reproductive organs, and with no preserved evidence of internal structures, these organisms' existence is very strange by current standards. The most widely accepted hypothesis is that they could suck nutrients from the water around them by osmosis. The fronds were com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arborea (genus)
''Arborea'' is a genus of petalonamid that was originally considered as being synonymous with '' Charniodiscus''. It consisted of a frond-like body long that was attached to the substrate via a holdfast that possessed many concentric rings on it. Species which were thought to have been within the genus ''Charniodiscus'' are now being interpreted as belonging to the genus ''Arborea'' with the latter of which being considered synonymous with ''Charniodiscus''. ''A. arborea'' was first described from South Australia, and is the most abundant petalonamid in the Flinders Ranges. The genus currently contains 5 known species with 3 of them originally being species of ''Charniodiscus''; the species include ''A. arborea'', ''A. denticulata'', ''A. longa'', ''A. oppositus'' and ''A. spinosa''. See also *List of Ediacaran genera The existence of life, especially that of animals, before the Cambrian had long been the subject of debate in paleontology. The apparent suddenness of the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaojiashania
''Gaojiashania cyclus'' is a worm-like, soft bodied organism with an epibenthic mode of life. Composed of repeating ring-like units, ''G. cyclus'' is flexible, soft, and not easily preserved. Pyritization prior to decay of soft parts results in the well preserved casts and molds we see today. Morphology, anatomy, & behavior Initially thought to be an annelid, ''G. cyclus'' is a soft bodied organism with small, hard, internal rings. Specimen morphology does not have much variation, tube lengths range from 30 to 60 mm and have constant diameter. Specimens are composed of repeating flexible units, subdivided further into annuli (Figure 2). Method of fossilization ''Gaojiashania cyclus'' are not preserved as a whole due to their soft bodies, and the only record that currently exists are impressions left behind by these organisms (Fig. 3). That being said, the impressions themselves are still fossilized and must undergo processes to become so. Three types of preservation ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
