''Skinnera'' is an

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 th ...

-aged fossil found in Australia. It was discovered by A.L. Halliday and M.M. Bruer near Mount Skinner in the locality of Anmatjere, in the

Northern Territory of Australia The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Aust ...

some time before 1969. Mary Wade of the

University of Adelaide The University of Adelaide (informally Adelaide University) is a public research university located in Adelaide, South Australia. Established in 1874, it is the third-oldest university in Australia. The university's main campus is located on N ...

originally formally described ''Skinnera'' as a medusa.

Description

''Skinnera'' is a small, disk-shaped fossil preserved as a composite mould. Specimens range in diameter from most are about across. They are slightly domed and all approximately 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,

Diversity

There is only one known species, ''S. brooksi.''

Discovery

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 The Ediacaran fossil ''Hallidaya'', a close relative of '' Skinnera'' lived in Belomorian (559-550 Ma) 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 Aus ...

brueri,'' for the discoverers, and Form B ''Skinnera brooksi'' for the location. Wade (1969) described ''Skinnera'' as a medusa, though, other sources classify it as a

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 ...

n related to ''

Tribrachidium ''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. Etymology ...

'' and ''Hallidaya''.

Distribution

''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.

Taphonomy

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.

Significance

''S. brooksi'' was described by Mary Wade, a leading female paleontologist at the time in a male dominated field.

References

{{Taxonbar, from=Q21397011 Ediacaran life Fossils of Australia