Archimedes (bryozoan) Archimedes (bryozoan) Archimedes is a genus of bryozoans belonging to the family Fenestellidae. The first use of the term "Archimedes" in relation to this genus was in 1838. This genus of bryozoans is named "Archimedes" because of its corkscrew shape, in analogy to the Archimedes' screw, a type of water pump which inspired modern ship propellers. These forms are pretty common as fossils but they have been extinct since the Permian. These bryozoans lived from the Carboniferous period (Tournaisian age) to the Permian period (Leonard age) (345.3 to 268.0 Ma), when this genus became extinct. "Archimedes" is a genus of
Screw meaning of the word "screw" has long involved the idea of a helical screw thread, but the Archimedes screw and the screw gimlet (like a corkscrew) preceded the fastener. The word "bolt" is also a very old word, and it was used for centuries to refer to metal rods that passed through the substrate to be fastened on the other side, often via nonthreaded means (clinching, forge welding, pinning, wedging, etc.). The connection of this sense to the sense of a door bolt or the crossbow bolt is apparent. In the 19th century, bolts fastened via screw threads were often