Skinnera brooksi | |
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Artist restoration of Skinnera brooksi | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | † Trilobozoa |
Genus: | † Skinnera Wade, 1969 |
Species: | †S. brooksi |
Binomial name | |
†Skinnera brooksi Wade, 1969 | |
Skinnera is an Ediacaran-aged fossil found in Australia. It was discovered by A.L. Halliday and M.M. Bruer near Mount Skinner in the locality of Anmatjere, [1] in the Northern Territory of Australia some time before 1969. Mary Wade of the University of Adelaide originally formally described Skinnera as a medusa.
Skinnera is a small, disk-shaped fossil preserved as a composite mould. Specimens range in diameter from 3.9–32 mm (0.15–1.26 in) most are about 10 mm (0.39 in) across. They are slightly domed and all approximately 2 mm (0.079 in) tall. The fossils have three-fold symmetry and are characterized by three large, pouch-shaped depressions in the center which are speculated to be the stomach. These central depressions are connected to an outer rim of approximately 15 smaller pouch-shaped depressions along the perimeter of the disk by canals, [2]
There is only one known species, S. brooksi. [2]
A.L. Halliday, geologist, and M.M. Bruer, field assistant, were on a geological expedition near Mount Skinner while working for Kennecott Explorations, Pty. Ltd. when they found fossiliferous deposits near the mountain. They marked off three locations, Mt. Skinner No. 1-3. The majority of fossils were found between sites Mt. S2 and Mt. S3. Halliday and Bruer notified Mary Wade of the Department of Geology at the University of Adelaide. Wade collected additional fossils aided by Halliday and Bruer. Two types of fossils were found which Wade designated as Form A and Form B. There were about twice as many fossils of Form A than Form B. Wade named Form A Hallidaya brueri, for the discoverers, and Form B Skinnera brooksi for the location. Wade (1969) described Skinnera as a medusa, [2] though, other sources classify it as a trilobozoan related to Tribrachidium and Hallidaya. [3]
Skinnera is known from three sites in the Northern Territory of Australia near Mount Skinner. Fossils were primarily found between sites Mt. Skinner 2 and Mt. Skinner 3. [2]
The fossils were found in flaggy bedding of maroon and green shales with subgreywacks, impure siltstone, and claystones. The fossils are found flattened, parallel to the bedding plane with the dorsal surface up. [2]
S. brooksi was described by Mary Wade, a leading female paleontologist at the time in a male dominated field. [2]
Arkarua adami is a small, Precambrian disk-like fossil with a raised center, a number of radial ridges on the rim, and a five-pointed central depression marked with radial lines of five small dots from the middle of the disk center. Fossils range from 3 to 10 mm in diameter.
Dickinsonia is an extinct genus of basal animal that lived during the late Ediacaran period in what is now Australia, China, India, Russia and Ukraine. The individual Dickinsonia typically resembles a bilaterally symmetrical ribbed oval. Its affinities are presently unknown; its mode of growth is consistent with a stem-group bilaterian affinity, though some have suggested that it belongs to the fungi, or even an "extinct kingdom". The discovery of cholesterol molecules in fossils of Dickinsonia lends support to the idea that Dickinsonia was an animal.
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.
The Adelaide Superbasin is a major Neoproterozoic to middle Cambrian geological province in central and south-east South Australia, western New South Wales, and western Victoria.
Rangea is a frond-like Ediacaran fossil with six-fold radial symmetry. It is the type genus of the rangeomorphs.
Aspidella is an Ediacaran disk-shaped fossil of uncertain affinity. It is known from the single species A. terranovica.
Thectardis avalonensis is a triangular-shaped member of the Ediacaran biota, dating from 575 to 565 million years ago. The organism took the form of an elongated cone with a central depression, and its apex was anchored to the substrate.
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.
The Ediacaranbiota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period. These were composed of 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.
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.
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.
Mary Julia Wade was an Australian palaeontologist, known for her role as the Deputy Director of the Queensland Museum. Some of her most renowned work was on the Precambrian Ediacaran Biota in South Australia.
Tamga hamulifera is a disk-shaped fossil from Precambrian strata of the White Sea area, in Russia.
Ediacaran type preservation relates to the dominant preservational mode in the Ediacaran period, where Ediacaran organisms were preserved as casts on the surface of microbial mats.
Arumberia is an enigmatic fossil from the Ediacaran period originally described from the Arumbera Sandstone, Northern Territory, Australia but also found in the Urals, East Siberia, England and Wales, Northern France, the Avalon Peninsula and India. Several morphologically distinct species are recognized.
The Ediacaran fossil Hallidaya, a close relative of Skinnera lived in Belomorian of the Late Ediacaran period prior to the Cambrian explosion and thrived in the marine strata on the ocean floor of what is now considered Australia. These fossils were disk-shaped organisms that were slightly dome shaped with tri-radial symmetry. These Ediacaran organisms thrived by living in low-energy inner shelf, in the wave- and current-agitated shoreface, and in the high-energy distributary systems.
Anmatjere is a locality in the Northern Territory of Australia located about 1,088 kilometres (676 mi) south of the territory capital of Darwin.
Eoporpita is a disc or ellipse-shaped Ediacaran fossil with unsure taxonomy/classification. It is known from its type species, Eoporpitamedusa, the only species within the genus Eoporpita.
Medusoids or discoids are extinct organisms that are superficially similar to jellyfish that lived during the end of the Precambrian, the Ediacaran, and early Cambrian periods. It is believed that they were among the oldest animals, together with the petalonams, due to the discovery of Medusoid fossils from approximately 580 million years ago. They were part of the Ediacaran fauna.
Bonata is a genus of disk-shaped, soft-bodied organism which were originally found in the Ediacaran deposits of the White Sea area, Russia. It has been poorly studied because of the lack of fossil specimens found in the region since the 1980's. It contains a single species, Bonata septata.