| Albumares brunsae Temporal range: Ediacaran, between | |
|---|---|
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| Artists interpretation of Albumares brunsae by Apokryltaros. | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | † Trilobozoa |
| Family: | † Albumaresidae |
| Genus: | † Albumares Fedonkin, 1976 |
| Species: | †A. brunsae |
| Binomial name | |
| †Albumares brunsae Fedonkin, 1976 | |
Albumares brunsae is a tri-radially symmetrical fossil animal that lived in the late Ediacaran seafloor. It is a member of the extinct group Trilobozoa. [1]
The generic name Albumares derives from the Latin Mare Album (White Sea). [1] The specific name "brunsae" honors Elizabeth P. Bruns, an early 20th-century Russian geologist noted for her extensive and important research of the Upper Precambrian [lower-alpha 1] stratigraphy of European Russia. [1]
Fossils of the Albumares brunsae are known from deposits on the Verkhovka formation on the Syuzma River in the Onega Peninsula of the White Sea, Arkhangelsk Region, Russia. [1] [2] There are reports about Albumares sp. from the Rawnslay Quartzite, Flinders Ranges in the South Australia, but photographs or description of these fossils have not yet been published. [3]
Albumares fossils are preserved as negative, low impressions on the bases of sandstone beds. The fossil exhibits circular, trefoil-like (three-lobe) form, and is covered by three dendritic-branched furrows and three oval ridges that radiate from the center. The lobes are twisted into weak spirals. [4] [5] [1] [2] [6]
The diameters of known specimens vary from 8 to 15 millimeters. [4]
Albumares was originally described by Mikhail Fedonkin as a free-swimming scyphozoan jellyfish. The branched furrows on the fossil were interpreted as imprints of a system of internal radial canals and tentacles along the outer margin of the fossil, with the three oval ridges described as imprints of mouth lobes [1] [2] or gonades. [6]
Later, with the discovery of the closely related Anfesta and with their seeming affinities to Tribrachidium , Fedonkin appointed these animals to the Trilobozoa , an extinct group of the tri-radially symmetrical coelenterate-like animals that only superficially resembled cnidarians. [6] [7] Originally, Trilobozoa was established as a class in the phylum Coelenterata, but since Coelenterata has been divided into two separate phyla, Cnidaria and Ctenophora, Trilobozoa itself has been promoted to the rank of phylum. [8]
According to the latest research, Albumares was a soft-bodied benthic organism that temporarily attached (but did not adhere) to the substrate of its habitat (microbial mats). This fossil typically displays as an imprint of the upper side of the animal's body, and often some elements of its internal structure can be discerned. The branched furrows on the fossil are imprints of radial grooves on the surface of the animal, while the three ridges in the central part of the fossil are imprints of cavities within the body. Presumably, this system of grooves and cavities could be related to the collection and digestion of food particles. [4]
The Ediacaran Period 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. It is the last period of the Proterozoic Eon as well as the so-called Precambrian "supereon", before the beginning of the subsequent Cambrian Period marks the start of the Phanerozoic Eon, where recognizable fossil evidence of life becomes common.
Dickinsonia is a genus of extinct organism that lived during the late Ediacaran period in what is now Australia, China, Russia and Ukraine, most likely a basal animal. It is one of the best known members of the Ediacaran biota. The individual Dickinsonia typically resembles a bilaterally symmetrical ribbed oval. Its affinities are presently unknown; its mode of growth has been considered consistent with a stem-group bilaterian affinity, though various other affinities have been proposed. The discovery of cholesterol molecules in fossils of Dickinsonia lends support to the idea that Dickinsonia was an animal, though these results have been questioned.
Kimberella is an extinct genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the gastropods, although its affinity with this group is contentious.
Tribrachidium heraldicum is a tri-radially symmetric fossil animal that lived in the late Ediacaran (Vendian) seas. In life, it was hemispherical in form. T. heraldicum is the best known member of the extinct group Trilobozoa.
Vendobionts or Vendozoans (Vendobionta) are a proposed very high-level, extinct clade of benthic organisms that made up of the majority of the organisms that were part of the Ediacaran biota. It is a hypothetical group and at the same time, it would be the oldest of the animals that populated the Earth about 580 million years ago, in the Ediacaran period. They became extinct shortly after the so-called Cambrian explosion, with the introduction of fauna formed by more recognizable groups and more related to modern animals. It is very likely that the whole Ediacaran biota is not a monophyletic clade and not every genus placed in its subtaxa is an animal.
Yorgia waggoneri is a discoid Ediacaran organism. It has a low, segmented body consisting of a short wide "head", no appendages, and a long body region, reaching a maximum length of 25 cm (9.8 in). It is classified within the extinct animal phylum Proarticulata.
Cephalonega stepanovi is a fossil organism from Ediacaran deposits of the Arkhangelsk Region, Russia. It was described by Mikhail A. Fedonkin in 1976
Vendia is a genus of oval-shaped, Ediacaran fossils ranging from 4.5 to 12.5 mm long. The body is completely segmented into isomers, which are arranged alternately in two rows longitudinal to the axis of the body. The larger isomers cover the smaller ones externally but the posterior ends of all the isomers remain free. The transverse elements decrease in size from anterior to posterior and are all inclined in the same direction.
Trilobozoa is a phylum of extinct, sessile animals that were originally classified into the Cnidaria. The basic body plan of trilobozoans 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.
Academician Mikhail Aleksandrovich Fedonkin is a Russian paleontologist specializing in documentation of the earliest animals' body fossils, tracks, and trails. He has also described numerous Vendian-aged fossils including Hiemalora, Cephalonega, and Nimbia occlusa.
Bomakellia kelleri is a species of poorly understood Ediacaran fossil organism represented by only one specimen discovered in the Ust'-Pinega Formation of the Syuzma River from rocks dated 555 million years old. Bomakellia was originally interpreted as an early Arthropod. A study by B. M. Waggoner even concluded that the organism was a primitive anomalocarid and erroneously identified the ridges of supposed Cephalon as being eyes making Bomakellia the oldest known animal with vision. But this hypothesis has not reached acceptance, nor acknowledgement.
Ovatoscutum concentricum is one of many enigmatic organisms known from the Ediacaran deposits of the Flinders Ranges, Australia, and the White Sea area in Russia, dating around 555 Ma.
Anfesta stankovskii is a tri-radially symmetrical fossil animal that lived in the late Ediacaran (Vendian) seafloor. It is a member of the extinct group Trilobozoa.
Proarticulata is a proposed phylum of extinct, bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits, and dates to approximately 567 to 550 million years ago. The name comes from the Greek προ = "before" and Articulata, i.e. prior to animals with true segmentation such as annelids and arthropods. This phylum was established by Mikhail A. Fedonkin in 1985 for such animals as Dickinsonia, Vendia, Cephalonega, Praecambridium and currently many other Proarticulata are described.
Rugoconites is a genus of Ediacaran biota found as fossils in the form of a circular or oval-like impression preserved in high relief, six or more centimeters in diameter. The fossils are surrounded by frills that have been interpreted as sets of tentacles. The bifurcating radial ribs, spreading from a central dome, serve to distinguish this genus from the sponge Palaeophragmodictya, and may represent the channels of the gastrovascular system. Fossils of Rugoconites have been interpreted as early sponges, although this is countered by Sepkoski et al. (2002), who interpreted the organism as a free-swimming jellyfish-like cnidarian; similar to Ovatoscutum. However, the fossil is consistently preserved as a neat circular form and its general morphology does not vary, therefore a benthic and perhaps slow-moving or sessile lifestyle is more likely. Ivantstov & Fedonkin (2002), suggest that Rugoconites may possess tri-radial symmetry and be a member of the Trilobozoa.
Vendiamorpha is a class of extinct animals within the Ediacaran phylum Proarticulata.
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.
Archaeaspinus fedonkini is an extinct proarticulatan organism from the Late Precambrian (Ediacaran) period.
Cephalozoa are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
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