''Archimedes'' is a genus of
bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...
ns belonging to the family
Fenestellidae. The first use of the term "Archimedes" in relation to this genus was in 1838.
Etymology
This genus of bryozoans is named ''Archimedes'' because of its corkscrew shape, in analogy to the
Archimedes' screw
The Archimedes screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest hydraulic machines. Using Archimedes screws as water pumps (Archimedes screw pump (ASP) or screw pump) dates back ...
, a type of water pump which inspired modern ship propellers in turn named after the
ancient greek polymath. These forms are common as fossils but they have been extinct since the Permian.
Species
*''Archimedes orientalis'' Schulga-Nesterenko 1936
*''Archimedes regina'' Crockford 1947
*''Archimedes stuckenbergi ''Nikiforova 1938
[
]
Fossil range
These bryozoans lived from the Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
period (Tournaisian
The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from Ma to Ma. It is preceded by the Famennian (the uppermost stage ...
age) to the Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...
period (Leonard age) (345.3 to 268.0 Ma), when this genus became extinct.[The Paleobiology Database]
/ref>[Sepkoski, Jac]
Sepkoski's Online Genus Database - Bryozoa
/ref>
Description
''Archimedes'' is a genus of fenestrate
Fenestration may refer to:
* Fenestration (architecture), the design, construction, or presence of openings in a building
* Used in relation to fenestra in anatomy, medicine and biology
* Fenestration, holes in the rudder of a ship to reduce the w ...
bryozoans with a calcified skeleton of a delicate spiral-shaped mesh that was thickened near the axis into a massive corkscrew-shaped central structure. The most common remains are fragments of the mesh that are detached from the central structure, and these may not be identified other than by association with the "corkscrews", that are fairly common. Specimens in which the mesh remains attached to the central structure are rare.zooid
A zooid or zoöid is a single animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooi ...
s) lived on one side of the mesh, and can be recognized for the two rows of equally distanced rimmed pores. Inside the branches, neighbouring individuals were in contact through small canals. Bryozoans are stationary epifaunal suspension feeders.[
]
Distribution
The majority of fossils of this genus are distributed throughout Europe and North America, but they have also been found in sediments of Afghanistan, Canada, Russia, and Australia.[
]
References
{{Authority control
Prehistoric bryozoan genera
Carboniferous first appearances
Permian genus extinctions
Carboniferous animals of Asia
Fossils of Georgia (U.S. state)
Paleozoic life of Alberta
Paleozoic life of Nunavut