Oct 26, 2015 · By examining these imprints at the youngest known Ediacaran fossil site – Farm Swartpunt, in southern Namibia – the researchers found evidence suggesting that the impact of the earliest animals on the Ediacarans, during a period known as the Cambrian explosion, was taking its toll. These earliest animals went on to form the animal families ... The disappearance of the Ediacarans from the fossil record has long troubled biologists. Leading theories are a catastrophic mass extinction, that Ediacarans got eaten or had their habitat ...Lichens are often highlighted as important life forms in the early evolution of terrestrial vegetation. They have been postulated to go as far back as the early Proterozoic, suggested as a model to classify Ediacaran macrofossils, presumed to have existed as protolichens in the Early Phanerozoic, reconstructed as precursors of major clades of …Fig. 1. Ediacaran fossils on bed surfaces from the Mistaken Point Assemblage, Avalon Peninsula, Newfoundland. A, Schematic drawing and accompanying photograph of a bedding plane containing spindles (S), a bush-shaped morph of Bradgatia (B), a lobate morph of Ivesia (L), and a Charnia/Charniodiscus (C). Scale bar = 4 cm. B, Close-up of …Nov 13, 2017 · A cast fossil of a creature called Gaojiashania, a Cambrian cousin that lived during the last 10 million years of the Ediacaran period. This fossil was found near Mount Dunfee in Nevada. The ... List of Ediacaran genera. This is a list of all described Ediacaran genera, including the Ediacaran biota. It contains 227 genera. Bilaterally symmetric organism with ovoid shape, and midline axial zone. Junior synonym of Onegia nenoxa (according to Grazhdankin, Ph.D. ms.). [15] [16]Ediacarans, to me, lack that microbial look that lichens often have of a central colony with growing margins often surrounded by younger satellite colonies. Others tend to be bunched and irregular.Coupled with the evidence for ‘Cambrian Ediacarans’ (Hoyal Cuthill, 2022 ), this suggests a possible ~50 million year (Myr) (or longer) coexistence of Ediacarans and total-group …The Ediacaran Fauna (600-542 MY) The Ediacaran Fauna refers to an assemblage or group of fossil animals and plants that are dominantly soft-bodied and have been found in rocks from the late Precambrian Eon. Some of the animals in the Ediacaran Fauna may have had some body parts made of chitin, but organisms had not yet evolved to have full ...Radial structures reported from Ediacarans often extend beyond the central disc and thus cannot be impressions of radial canals. Simple discoidal Ediacarans are still less plausible as cnidarians: they lack structures diagnostic of cnidarian morphology, including even the most basic radial patterns seen in anthozoan trace fossils such as …The Ediacaran-Cambrian (E-C) transition marks the most important geobiological revolution of the past billion years, including the Earth's first crisis of macroscopic eukaryotic life, and its most spectacular evolutionary diversification. Here, we describe competing models for late Ediacaran extinction, summarize evidence for these models, and ...This latest Ediacaran interval (the ‘Nama’) may therefore represent the earliest phase of the Cambrian Explosion. The Ediacaran–Cambrian (E–C) transition …10 Aug 2018 ... Cambrian-Aged Ediacaran Organism Reconfirms Explosiveness of the Cambrian Explosion ... According to a new paper in the journal Palaeontology, for ...Sep 4, 2023 · The end-Neoproterozoic transition marked a gradual but permanent shift between distinct configurations of Earth's biosphere. This interval witnessed the demise of the enigmatic Ediacaran Biota, usher... 555 Ma: Ediacara Hills. Material from the Ediacara Hills (Flinders Ranges) has still not been precisely dated; it is assumed to be approximately coeval with the White Sea fossils, in the region of 555 Ma (see below), but it could be as young as the +1 to +2 d13C interval, dated at 549 to 543 Ma in southern Namibia. Martin et al. (2000: 844). Yorgia is known from Australia and Russia (~555 mya), and appears to be a transitional form between two other ediacarans, Dickinsonia and Spriggina. It has what appears to be a “head” end with an asymmetrical lobe, and a segmented body in a glide reflection pattern, growing up to 25cm long (10″).The coastal successions of Newfoundland, Canada, contain some of the oldest examples of the Ediacaran biota. Dated to between 570 and ~560 million years in age, rocks of the Conception and St. John's groups possess thousands of fossils, largely preserved beneath volcanic tuffs, recording successive 'snapshots' of Ediacaran seafloor communities.The disappearance of the Ediacarans from the fossil record has long troubled biologists. Leading theories are an environmental mass extinction; or that the Ediacarans got eaten or had their ...The Ediacaran–Cambrian (E–C) transition marks the most important geobiological revolution of the past billion years, including the Earth’s first crisis of macroscopic eukaryotic life, and its most spectacular evolutionary diversification. Here, we describe competing models for late Ediacaran extinction, summarize evidence for these …13 Mar 2014 ... A dense mat of microbes covered the entire ocean floor. There were no coral reefs and swimming fish. Instead Charnia stalks swayed with the ...4 Sept 2023 ... The long fuse of the Cambrian Explosion was lit on the Ediacaran benthos. Far from being an ecological impediment, the Ediacaran Biota at the ...May 17, 2022 · The earliest Ediacarans lived on the sea floor in deep-sea environments, but as time went on, some of them moved up into shallower regions that were much more changeable and also richer in oxygen. Debate about engimatic Ediacarans far from over Palaeontologist Jim Gehling of the South Australian Museum is a world expert in Ediacaran biota from the red Precambrian sandstone of the Flinders ...A Stromatoveris fossil. Cuthill and Han argue that S. psygmoglena was actually a hardy Ediacaran, holding on to life while the rest of the species died out. After studying 200 samples of the S ...The large size (ca. 1 m) of some Ediacaran fossils is reasonable for sessile photosynthetic symbioses, and much bigger than associated burrows of metazoans not preserved. Microscopic tubular structures and darkly pigmented cells in permineralized late Precambrian fossils from Namibia and China are also compatible with interpretation as …It suggests that the earliest solitary Ediacarans furnished a framework for the development of cell and tissue specialization, including the formation of epithelia and complex connective tissues ...c. 17 °C. (3 °C above modern) The Ediacaran period ( / ˌiːdiˈækərən, ˌɛdi -/ EE-dee-AK-ər-ən, ED-ee-) [3] is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya, to the beginning of the Cambrian period at 538.8 Mya. [4] It is the last period of the Proterozoic ... What Are the Ediacarans? First discovered in 1946 in the Ediacara hills in the Flinders ranges of South Australia, these evolutionary oddballs bear only the vaguest …Life Forms. - microscopic bacteria [3.4 billion years ago] - bacteria evolved into different forms seeking out different ways to get energy over time. - one type of bacteria is called the cyanobacteria- first multicelled organisms occurs in fossil forms of 600 million years old. - Ediacarans resemble nothing of today's modern organisms.Ediacarans, Protolichens, and Lichen-Derived Penicillium: A Critical Reassessment of the Evolution of Lichenization in Fungi. 2018, Transformative Paleobotany: Papers to Commemorate the Life and Legacy of Thomas N. Taylor. Show abstract. Lichens are often highlighted as important life forms in the early evolution of terrestrial vegetation. …Fig. 1 from Just et al. 2014. Dendrogramma discoides starred at left; rest of specimens are D. enigmatica. Specimens have shrunken due to preservation in alcohol.Mean atmospheric oxygen is predicted to increase by around 50% during the Ediacaran period. This is primarily due to a rise in the organic carbon burial flux from ~4 × 10 12 mol yr −1 to ~8 × ...In this video we'll take a look at the broader story of life's development in the Ediacaran period, concerning ourselves primarily with the development of th...13 Oct 2022 ... During the Ediacaran and earliest Cambrian the mid-ocean ridges were in a low-activity (like today) in which aragonite is easier to form. During ...Some are most like cnidarians, worms, or soft-bodied relatives of the arthropods. Others are less easy to interpret and may belong to extinct phyla. But besides the fossils of soft bodies, Vendian rocks contain trace fossils, probably made by wormlike animals slithering over mud. The Vendian rocks thus give us, and YOU through our virtual ... The Ediacaran biota are the fauna of the Ediacaran period. This geological period was from 635–542 million years ago, but the fossil biota was only from 575–542 million years ago. This was after a series of ice ages and just before the Cambrian period. The biota consists of soft-bodied multicellular organisms, probably animals, which left ...Fig. 1 from Just et al. 2014. Dendrogramma discoides starred at left; rest of specimens are D. enigmatica. Specimens have shrunken due to preservation in alcohol.This latest Ediacaran interval (the ‘Nama’) may therefore represent the earliest phase of the Cambrian Explosion. The Ediacaran–Cambrian (E–C) transition …12 Dec 2018 ... Ediacaran fossils document the early evolution of complex megascopic life, contemporaneous with geochemical evidence for widespread marine ...New Ediacaran fossil finds at Sekwi Brook occur in lower shoreface to offshore transition beds at the top of the Blueflower Formation, which are the most shallow-water facies and the youngest strata in which Ediacara-type fossils have been described from the Mackenzie Mountains of NW Canada.In 1946, a geologist, Reg Sprigg visited the Ediacara Hills in the Flinders Ranges. On the bases of sandstone slabs, he found disc-like impressions that looked ...11 Aug 2016 ... The event, known as the end-Ediacaran extinction, took place 540 million years ago. The earliest life on Earth consisted of microbes – various ...Ediacarans make up the oldest known truly diverse metazoan assemblages and are known globally. However , few sites have produced abundant fossils, and until recently such fossils were unknown in ...May 10, 2018 · A new study of Ediacara Biota indicates that the Ediacaran and Cambrian Periods on Earth may not have been as separate as previously envisioned. Instead, they could be considered part of an ‘ecological and evolutionary continuum.’. The Ediacara Biota refers to the earliest communities of complex, macroscopic, multicellular organisms known ... Ediacarans with a body outline similar to that of the enigmatic Podolian species, but with serially arranged oval bodies near the midline may not be as distant phylogenetically to it, as the plain morphology of fossils suggests. Their shields frequently show tuberculation (e.g., Onega; Ivantsov, 2007) similar to that on the shield of …Jul 29, 2016 · The most successful of these were the Ediacarans, which spread around the globe about 600 million years ago. They were a largely immobile form of marine life shaped like discs and tubes, fronds ... Ediacaran Period, uppermost division of the Proterozoic Eon of Precambrian time and latest of the three periods of the Neoproterozoic …The Ediacaran Period is an interval of geological time ranging 635 to 541 million years ago. It was a time of immense geological and biological change, and records the transition from a planet largely dominated by microscopic organisms, to a Cambrian world swarming with animals. It is therefore one of the most fascinating and unique periods in ...Ediacaran definition: . See examples of EDIACARAN used in a sentence.1. Introduction. Rangeomorphs were conspicuous members of the Ediacaran biosphere, present from roughly the end of the Gaskiers glaciation through to the beginning of the Cambrian period (c. 575–540 Ma).As the first substantial instances of large complex organisms in the fossil record, they mark a key transition in geobiological history, …National Heritage List inscription date 11 January 2007 In 1946, geologist Reginald Sprigg discovered fossil imprints in rocks in the Flinders Ranges at the old Ediacara minefield. This discovery was the first time the fossilised remains of an entire community of soft-bodied creatures had been found in such abundance anywhere in the …Which of the organisms below give support for the colonial theory of animal origins? A) Spriggina B) choanoflagellates C) Ediacarans D) trilobites E) club fungiThe Ediacaran Period [635 to 539 million years (Ma) ago] is a pivotal period in Earth history, archiving the rise of complex macroscopic life ().This evolutionary …Study with Quizlet and memorize flashcards containing terms like Unique biota preserved as soft bodied impressions whose phylogenetic relationship to modern biota is still unknown; often described as quilted air mattresses, Describe some biologic features of Ediacaran biota, Proposed name for Ediacaran biota if they are an extinct evolutionary lineage and …Sep 4, 2023 · ‘Ediacarans’ are marked in violet; bilaterians in red. Violet arrows indicate the withdrawal and concentration of suspended organic carbon (black dots) by suspension-feeding Ediacarans. Green denotes bacterial mats, light blue is the water column, and sandy is the sediment column. Reflections on Staggered Bilateral Symmetry in Dickinsonia and other Ediacarans Enrico Savazzi Hagelgränd 8, 75646 Uppsala, Sweden. E-mail: [email protected] The body-plan of Dickinsonia and other Ediacaran organisms has been interpreted as a series of fluid-filled cavities surrounded by thin membranes D. Seilacher.Ediacarans are as “strange as life on another planet, but easier to reach,” described paleontologist Adolf Seilacher in a 2007 paper for the Geological Society of London, Special Publications.Ediacarans are truly ancient organisms, but the fossils we do have might be of their internal structure, meaning we don’t know what they looked like at all. This resource is best suited to Year 7, 8, and 10 Biology and Earth and Space students who are learning about the classification and evolution of species as well as Senior Biology and Earth Science …They lived before the dawn of true animals, some 580 million years ago, and scientists still aren’t sure whether they were animals, plants, or neither. These mysterious creatures known as Ediacarans have puzzled researchers for years. Now, however, new scans of rare 3D Ediacaran fossils found in Namibia have revealed more about these …Shields Down. The weakened magnetic field Tarduno and his colleagues discovered roughly coincided with the end-Ediacaran extinction around 542 million years ago—a mass die-off of primitive ...Encased in “death masks” made of the mineral pyrite (“fool's gold”), these soft-bodied organisms avoided rot and decay long enough to make it into the fossil record, paleontologists say ...Viewpoint: No, the late Precambrian life forms (Ediacaran biota) are not related to modern animals. Before 1946, a huge gap existed in the fossil record. There seemed to be no complex animal fossils at all until the start of the Cambrian period, about 544 Mya, when nearly all animal phyla now on Earth appeared in a relatively short time span. Ediacarans, fishes, reptiles, flowering plants c. Ediacarans, flowering plants, fishes, reptiles d. Flowering plants, reptiles, fishes, Ediacarans. Expert Solution. Trending now. This is a popular solution! Step by step. Solved in 2 steps. SEE SOLUTION Check out a sample Q&A here. Knowledge Booster. Learn more about Evolutionary lineages. Need a deep-dive on …Encased in “death masks” made of the mineral pyrite (“fool's gold”), these soft-bodied organisms avoided rot and decay long enough to make it into the fossil record, paleontologists say ...Introduction. The Ediacaran–Cambrian (E–C) transition arguably marks the most important geobiological revolution of the past billion years, characterized by large perturbations to global geochemical cycles, a permanent step-change in the character of the sedimentary record, the rise of macroscopic eukaryotic life, and potentially one or more pulses of …Jan 12, 2016 · During the Ediacaran period, about 635 million to 541 million years ago, oxygen was sparse, the oceans were murky and marine organisms ate by absorbing nutrients floating around in the water. In 1946, a geologist, Reg Sprigg visited the Ediacara Hills in the Flinders Ranges. On the bases of sandstone slabs, he found disc-like impressions that looked ...7 Mar 2018 ... The Ediacaran Biota: The actual evidence of Proterozoic animals (even macroscopic animals) was actually first discovered some time ago. In 1872 ...Fall Semester 2022 Ediacaran Metazoans & the Cambrian Explosion. "Ediacara/Burgess Shale" by D.W. Miller . Key Points: •Most of metazoan diversity lies within Bilateria, the "worms" (very broadly defined.) •Bilaterians divide into two major clades: Protostomia (arthropods, annelids, mollusks, brachiopods, bryozoans, and their allies) …The Rise of Animals: Evolution and Diversification of the Kingdom Animalia. Mikhail A. Fedonkin, James G. Gehling, Kathleen Grey, Guy M. Narbonne, and PatriciaAre you curious about the era in which our Earth was formed, it's landscape, the various tectonic movements? No worries we have got you covered.Subscribe to ...15 Feb 2017 ... The oldest worm in the world? Sprigginia from the Ediacaran (550 MY) #WormWednesday (well, this is assuming Ediacarans were animals)Here, the authors describe a pathogenic fungus from a 400-million-year-old fossil plant from the Devonian Rhynie Chert in Scotland. They use advanced imaging methods to determine that the fungus ...Molecular clock studies along with fossil evidence even suggested that lichen-like organisms occurred as far back as the Precambrian Ediacaran period and that ...New Ediacaran fossil finds at Sekwi Brook occur in lower shoreface to offshore transition beds at the top of the Blueflower Formation, which are the most shallow-water facies and the youngest strata in which Ediacara-type fossils have been described from the Mackenzie Mountains of NW Canada.8 Dec 2021 ... et sp. nov. are described from the upper Ediacaran shallow-marine deposits of Ukraine, which are no younger than 557 Ma. The first two resemble ...Sep 3, 2014 · Fig. 1 from Just et al. 2014. Dendrogramma discoides starred at left; rest of specimens are D. enigmatica. Specimens have shrunken due to preservation in alcohol. How to say Ediacaran in English? Pronunciation of Ediacaran with 4 audio pronunciations, 3 translations, 1 sentence and more for Ediacaran.The term ‘Ediacara Biota’ is commonly used to refer to early megascopic fossils. •. This term is inconsistent, arbitrarily excludes certain fossils, and cannot be defined. •. Studies of early metazoan evolution must consider all fossils of Ediacaran age.Traditional Interpretation of Ediacaran Biota. Ediacara are a member of a modern phyla but with aberrant morphologies; possibly a proto-medusiod, annelida, or sea pen. Vendobionta. Proposed by German Seilacher, this is the now-extinct non-metazoan phylum in which Ediacara allegedly would have belonged to.The Rise and Fall of the Ediacaran Biota. Patricia Vickers-Rich, Patricia Komarower. Geological Society of London, 2007 - Science - 456 pages. The Proterozoic and early Phanerozoic was a time punctuated by a series of significant events in Earth history. Glaciations of global scale wracked the planet, interfingered with dramatic changes in ...The Nama Group south of Windhoek is divided into two Sub-basins – the Zaris Sub-basin in the north, and the Witputs Sub-basin in the south (Fig. 2; Germs, 1972a, Germs, 1983).The Zaris Sub-basin is separated from the Witputs Sub-basin by the Osis Arch, which, during deposition of the Zaris and lower-mid Schwarzrand subgroups at …1. Introduction. The Neoproterozoic Cryogenian to Ediacaran transition (ca. 635 Ma) was a critical time in the evolution of the geosphere and biosphere with rising O 2 levels, diversification of metazoans, and emergence from one of the most severe ice ages in Earth history, the Marinoan Snowball glaciation (Kirschvink, 1992, Hoffman et al., 1998, …Most Ediacarans appear to go extinct at or near the Cambrian boundary, but some members of the biota (both soft-bodied forms and skeletonized forms) survived into the Cambrian. A drop in diversity among Ediacarans near the Proterozoic-Cambrian boundary is thought by some to represent an extinction event, although the magnitude, cause and timing ... It is the hard skeletal materials of an organism that most com- monly survive post-mortem decay. An additional problem is that the Ediacarans were preserved by ...Ediacarans represent the first evidence of anything like intelligence on Earth.' Other researchers have dismissed his ideas, claiming the Ediacarans were in fact the forebears of primitive animals such as jellyfish. For decades the accepted view was that Ediacarans were animal ancestors.
Despite their ancient age, sterol metabolism within the gut of both organisms was already comparable to extant invertebrates. 8. Dickinsonia, one of the key Ediacaran animals, show no traces of dietary molecules, indicating a different feeding mode and possible external digestion analogous to modern Placozoa.. Characters of injustice 2
Sep 4, 2023 · The end-Neoproterozoic transition marked a gradual but permanent shift between distinct configurations of Earth's biosphere. This interval witnessed the demise of the enigmatic Ediacaran Biota, usher... By Shannon Hall. A fossilized imprint of Dickinsonia, mysterious organisms that may have been Earth’s earliest animals. Credit: Getty Images. Nearly 600 million years ago Earth’s continents ...The transition to the diverse and complex biosphere of the Ediacaran and early Paleozoic is the culmination of a complex history of tectonic, climate, and geochemical development.Here we describe Dickinsonia sp. from the terminal Ediacaran Shibantan Member limestone (ca. 551–543 Ma) of the Dengying Formation in the Yangtze Gorges area of South China. The stratigraphic ...The Ediacaran biota are the fauna of the Ediacaran period. This geological period was from 635–542 million years ago, but the fossil biota was only from 575–542 million years ago. This was after a series of ice ages and just before the Cambrian period. The biota consists of soft-bodied multicellular organisms, probably animals, which left ...11 Aug 2016 ... The event, known as the end-Ediacaran extinction, took place 540 million years ago. The earliest life on Earth consisted of microbes – various ...Ediacarans represent the first evidence of anything like intelligence on Earth.' Other researchers have dismissed his ideas, claiming the Ediacarans were in fact the forebears of primitive animals such as jellyfish. For decades the accepted view was that Ediacarans were animal ancestors.Fall Semester 2022 Ediacaran Metazoans & the Cambrian Explosion. "Ediacara/Burgess Shale" by D.W. Miller . Key Points: •Most of metazoan diversity lies within Bilateria, the "worms" (very broadly defined.) •Bilaterians divide into two major clades: Protostomia (arthropods, annelids, mollusks, brachiopods, bryozoans, and their allies) …Sep 4, 2023 · It is argued that the protracted and indirect effects of early bilaterian innovations, including escalations in sediment engineering, predation, and the largely understudied impacts of reef‐building, may best account for the temporal structure and possible selectivity of late‐Neoproterozoic extinctions. The end‐Neoproterozoic transition marked a gradual but permanent shift between ... 20 Apr 2015 ... Within the more than 30 million y range of the Ediacara Biota, fossils of these multicellular organisms demonstrate the advent of mobility, ...the Ediacarans died out completely at or before the Ediacaran-Cambrian boundary (the Kotlin interval); a considerable age separated the disappearance of the Ediacarans and the appearance of the small shelly faunas; the assemblages represented mass strandings rather than in situ associations; and perhaps stemming from this, ...Download MP3. The Cambrian explosion, around 541 million years ago, has long been regarded as a pivotal point in evolutionary history, as this is when the ancient ancestors of most of today’s ...decline of Ediacarans (Muscente et al., 2019; Bowyer et al., 2022) and the diversification of the animal phyla. The first, at 550 Ma, is the transition from diverse White Sea ecologies to the ‘depauperate’ Nama assemblage. The sec-ond records the decline of Nama Ediacarans around the Ediacaran–Cambrian boundary, 539 Ma. Finally,.
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Bianca price | "People have been slow to recognise that biological organisms can also drive mass extinction," said Simon Darroch, assistant professor of earth and environmental sciences at Vanderbilt University in …But most Ediacarans vanished from the fossil record near the beginning of the Cambrian. Some experts think this is evidence of mass extinction; others propose that conditions in the environment, especially the appearance of hard-shelled predatory animals with claws that could crawl and burrow, may have contributed over time to their decline....
Heavy metal songs | Mean atmospheric oxygen is predicted to increase by around 50% during the Ediacaran period. This is primarily due to a rise in the organic carbon burial flux from ~4 × 10 12 mol yr −1 to ~8 × ...Jan 15, 2020 · “Most Ediacarans are soft bodied and a bit squidgy,” says Simon Darroch, a paleontologist at Vanderbilt University in Tennessee. “The ability to form shells or skeletons didn’t evolve ... ...
Heavy weights | A new interpretation of fossilized soils (palaeosols) suggests that at least some Ediacaran (625–542 million years ago) organisms lived on land; thus these Ediacaran fossils were not animals ...Traditional Interpretation of Ediacaran Biota. Ediacara are a member of a modern phyla but with aberrant morphologies; possibly a proto-medusiod, annelida, or sea pen. Vendobionta. Proposed by German Seilacher, this is the now-extinct non-metazoan phylum in which Ediacara allegedly would have belonged to....
Brasil vs bolivia | The Ediacaran–Cambrian transition signals a drastic change in both diversity and ecosystem construction. The Ediacara biota (consisting of various metazoan stem lineages in addition to extinct ...11 Jan 2018 ... Royal Tyrrell Museum Speaker Series 2016 Calla Carbone - Royal Tyrrell Museum of Palaeontology "The Ediacaran Period: Glimpses of the ......
Turn off vanish mode instagram | The Ediacaran beasties first appeared in rocks about 750 million years old and persisted into the lowest part of the. Phanerozoic (to about 533 MA; the Early ...Ediacaran: [adjective] being or belonging to an assemblage of extinct multicellular marine organisms of the Late Precambrian era. ...
Ned flanders | Rocks of Ediacaran age (~635–541 Ma) contain the oldest fossils of large, complex organisms and their behaviors. These fossils document developmental and …The term ‘Ediacara Biota’ is commonly used to refer to early megascopic fossils. •. This term is inconsistent, arbitrarily excludes certain fossils, and cannot be defined. •. Studies of early metazoan evolution must consider all fossils of Ediacaran age....