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Frondomorph
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 considered 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 composed of bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboreomorpha
The arboreomorphs (Arboreomorpha) are ediacaran beings 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. '' Thaumaptilon'' is considered as one of the few cases that reached the Cambrian, though its placement is controversial. Some authors classify this group within Rangeomorpha and others together with Erniettomorpha The Erniettomorphs are a form of Ediacaran fossil consisting of rows of airbed-like tubes arranged along a midline with a glide symmetry. Representative genera include ''Ernietta'', '' Phyllozoon'', ''Pteridinium'', '' Swartpuntia''. Undisputed E ... in a larger group called Frondomorpha. References Petalonamae Ediacaran Ediacaran life Aquatic animals {{Ediacaran-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia. The Ediacaran Period's status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years. Although the period takes its name from the Ediacara Hills where geologist Reg Sprigg first discovered fossils of the eponymous Ediacaran biota in 1946, the type section is located in the bed of the Enorama Creek within Brachina Gorge in the Flinders Ranges of South Australia, at . The Ediacaran marks the first appearance of widespread multicellular fauna following the end of Snowball Earth glaciation events, the so-called Ediacaran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilateral Symmetry
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ..., and bacteria. External symmetry can be easily seen by just looking at an organism. For example, take the face of a human being which has a plane of symmetry down its centre, or a pine cone with a clear symmetrical spiral pattern. Internal features can also show symmetry, for example the tubes in the human body (responsible for transporting gases, nutrients, and waste products) which are cylindrical and have several planes of symmetry. Biological symmetry can be thought of as a balanced distribution of duplicate body parts or shapes within the body of an organism. Importantly, unlike in mathematics, symmetry in biology is always ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobozoa
''Trilobozoa'' (meaning "three-lobed animals") is a phylum of extinct mobile animals that were originally classified into the Cnidaria. The basic body plan of ''Trilobozoa'' is often a tri-radial or radial sphere-shaped form with lobes radiating from its centre. Fossils of trilobozoans are restricted to marine strata of the Late Ediacaran period. History and interpretations Originally, both Mikhail A. Fedonkin, Fedonkin and Runnegar presumed that there were 2-3 families within the Trilobozoa, those families being Albumaresidae Fedonkin, 1985 and Tribrachididae Runnegar, 1992. Although, affinities with the Conulariida were made because of the conulariids possessing similar three-fold symmetry. Mikhail Fedonkin later classified the Trilobozoa as a class of the Phylum (biology), Phylum Coelenterata. Most of the members of what is now the modern day classification for Trilobozoa were thought to have originally been free swimming Jellyfish. Tribrachidium was once interpreted as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eumetazoa
Eumetazoa (), also known as diploblasts, Epitheliozoa, or Histozoa, are a proposed basal animal clade as a sister group of the Porifera (sponges). The basal eumetazoan clades are the Ctenophora and the ParaHoxozoa. Placozoa is now also seen as a eumetazoan in the ParaHoxozoa. Several other extinct or obscure life forms, such as '' Iotuba'' and ''Thectardis'', appear to have emerged in the group. Characteristics of eumetazoans include true tissues organized into germ layers, the presence of neurons and muscles, and an embryo that goes through a gastrula stage. Some phylogenists once speculated the sponges and eumetazoans evolved separately from different single-celled organisms, which would have meant that the animal kingdom does not form a clade (a complete grouping of all organisms descended from a common ancestor). However, genetic studies and some morphological characteristics, like the common presence of choanocytes, now unanimously support a common origin. Traditiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swartpuntia
''Swartpuntia'' is a monospecific genus of erniettomorph from the terminal Ediacaran period, with at least three quilted, leaf-shaped petaloids — probably five or six. The petaloids comprise vertical sheets of tubes filled with sand. ''Swartpuntia'' specimens range in length from 12 to 19 cm, and in width from 11.5 to 140 cm. The margin is serrated, with a 1 mm wide groove. A 14 mm wide stem extends down the middle, tapering towards the top, and stopping 25 mm from the tip. The stem has a V shaped ornamentation on it. The original fossils were found at, and named after, the Swartpunt farm between Aus and Rosh Pinah in Namibia. The generic name comes from ''Swartpunt'', meaning ''black point'' in reference to the colour of the rocks. The specific name ''germsi'' honours Gerard Germs, who studied the Nama formation of geological beds. They are preserved in sandstone beds in the Spitzkopf Member from the Nama formation, which lie above an ash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pambikalbae
''Pambikalbae'' is a monospecific genus known from the Ediacaran Period (approximately 555 million years ago) of South Australia. Its morphology resembles the morphology of colonial cnidarians, such as sea pens or siphonophores. Description ''Pambikalbae'' had a broad, frondose-shaped body composed of multiple vanes extending from an axial stem, and containing a serial series of chambers. Specimens of ''Pambikalbae'' found thus far have measured approximately 20 to 30 cm in length, with a width of 12 cm at the widest point of the frondose-body, and 6.6 cm wide at the stem. Diversity ''Pambikalbae'' is a monospecific genus, with only one known species, ''Pambikalbae hasenohrae''. Discovery ''Pambikalbae hasenohrae'' was discovered within a fossiliferous exposure on the Nilpena pastoral property in the Flinders Ranges in South Australia. Pamela Hasenohr, an amateur geologist, found and brought the ''Pambikalbae'' fossils to the attention of Richard Jenkins, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arborea (genus)
''Charniodiscus'' is an Ediacaran fossil that in life was probably a stationary filter feeder that lived anchored to a sandy sea bed. The organism had a holdfast, stalk and frond. The holdfast was bulbous shaped, and the stalk was flexible. The frond was segmented and had a pointed tip. There were two growth forms: one with a short stem and a wide frond, and another with a long stalk, elevating a smaller frond about above the holdfast. While the organism superficially resembles the sea pens ( cnidaria), it is probably not a crown-group animal. ''Charniodiscus'' was first found in Charnwood Forest in England, and named by Trevor D. Ford in 1958. The name is derived from the fact that Ford described a holdfast consisting only of a double concentric circle, his species being named ''Charniodiscus concentricus''. Later it was discovered that a frond (''Charnia masoni'') was part of a closely related organism. ''Charnia ''Charnia'' is a genus of frond-like lifeforms belonging ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernietta
''Ernietta'' is an extinct genus of Ediacaran organisms with an infaunal lifestyle. Fossil preservations and modeling indicate this organism was sessile and “sack”-shaped. It survived partly buried in substrate, with an upturned bell-shaped frill exposed above the sediment-water interface. ''Ernietta'' have been recovered from present-day Namibia, and are a part of the Ediacaran biota, a late Proterozoic radiation of multicellular organisms. They are among the earliest complex multicellular organisms and are known from the late Ediacaran (ca. 548 Ma to 541 Ma). ''Ernietta plateauensis'' remains the sole species of the genus. Biology and paleoecology Fossil specimens show individuals to have lived partly buried in the substrate, as well as filled to some degree by substrate material. An exposed frill extended out of the substrate and was thought to have conducted feeding in the water column. Modeling based on fossil specimens show that the frill possessed an “upturned bell� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteridinium
''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 Prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rangea
''Rangea'' is a frond-like Ediacaran fossil with six-fold radial symmetry. It is the type genus of the rangeomorphs. ''Rangea'' was the first complex Precambrian macrofossil named and described anywhere in the world. ''Rangea'' was a centimetre- to decimetre-scale frond characterised by a repetitive pattern of self-similar branches and a sessile benthic lifestyle. Fossils are typically preserved as moulds and casts exposing only a leafy petalodium, and the rarity and incompleteness of specimens has made it difficult to reconstruct the three-dimensional (3D) morphology of the entire organism.Sharp, Alana C., Alistair R. Evans, Siobhan A. Wilson, and Patricia Vickers-Rich. "First Non-destructive Internal Imaging of Rangea, an Icon of Complex Ediacaran Life." Precambrian Research 299 (2017): 303-08. doi: 10.1016/j.precamres.2017.07.023 Fossilized ''Rangea'' consists of several vanes. Each vane has a foliate shape with a series of recessed furrows that run outwards at varying angles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porifera
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
