Cylindrus

Cylindrus is a name that has appeared in scientific literature as a proposed genus designation and, in some non-scientific contexts, as a fictional or descriptive term. In current major taxonomic databases and reference works, Cylindrus is not listed as an accepted genus of any extant organism. Because of its uncertain status in historical sources, Cylindrus is generally regarded as a dubious or unused name rather than a recognized taxon.

The word derives from Latin cylindrus, meaning a small cylinder or cylinder-like shape, and the name has been used primarily as a morphologic descriptor in the formation of taxon names. In various historical publications, authors briefly proposed Cylindrus for groups of microbes or microscopic fungi; however, these proposals were not adopted in subsequent revisions, and the species involved were reassigned to other genera or the name was left unused in later nomenclature.

In addition to scientific uses, Cylindrus has appeared in fiction and world-building as a place name or as a genus-like moniker for imagined organisms, drawing on its cylindrical connotation.

Because the term lacks a stable taxonomic basis, there is no single, authoritative description of Cylindrus, and any specific morphological or ecological characteristics are not established in a consistent way. When encountered in contemporary texts, Cylindrus typically signals either a historical footnote about nomenclatural practice or a fictional usage rather than a current, valid taxon.