''Archaeichnium'' is a member of the

Ediacaran biota The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organis ...

(635-542 Ma) first described by Martin Glaessner in 1963. It is characterized as a tubular

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

found in the

Nama group The Nama Group is a megaregional Vendian to Cambrian group of stratigraphic sequences deposited in the Nama Basin, Nama foreland basin in central and southern Namibia. The Nama Basin is a peripheral foreland basin, and the Nama Group was deposited ...

(570-543 Ma) of

South West Africa South West Africa was a territory under Union of South Africa, South African administration from 1915 to 1990. Renamed ''Namibia'' by the United Nations in 1968, Independence of Namibia, it became independent under this name on 21 March 1990. ...

, and is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus, containing only ''Archaeichnium haughtoni''.

Discovery

The rock containing the fossil that would eventually be named ''Archaeichnium haughtoni'' was first discovered in 1927 by Dr. H. F. Frommurze and S. H. Haughton while the two were doing geological mapping in Southwest Africa. The rock was found in the Nama group of Cambrian age in Central/ Southern

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

. In 1959, Haughton published the paper that described the fossils as early archaeocyathids, a taxon of sedentary reef-building organisms that doesn't usually appear in the fossil record until the late Cambrian. However, in 1963 Martin Glaessner revisited the rocks and determined that the fossilized animals did not actually distinctly possess the features that would classify it as an archaeocyathid, nor did he find it to share features with any known species. Glaessner dubbed the fossil anew as ''Archaeichnium haughtoni''

Description

''Archaeichnium'' is a tube-shaped fossil that may be preserved as hollow or infilled tubes. The overall shape of the tube is slightly tapered at one end so that it is vaguely conical. The structure is typically between 3–5 cm long with a 0.5 cm diameter, and the walls of the tube are 0.1 cm thick. Typically, the tubes exhibit longitudinal ribbing on the exterior, which creates 10-12 distinct "ribs". ''Archaeichnium'' also has latitudinal restrictions that organize it into approximately three sections cranio-caudally. When cross-sectioned, the tube lacks septae. The fossil is typically found in cross-bedded sandstone that is interpreted as a shallow marine depositional environment. Walls of the tube are typically agglutinated with small quartz grains.

Distribution

''Archaeichnium'' fossils are found in the Nasep quartzite stratigraphic unit within the Nama group at the following sites: * Nevada, United States of America * Namibia, Africa * Nilpena, Australia

References

{{Taxonbar, from=Q85742645 Index fossils Ediacaran life Ediacaran first appearances Monotypic prehistoric animal genera

Discovery

Description

Distribution

See also

References