''Rotularia'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of planispirally coiled fossil

polychaete worms Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are m ...

in the family Serpulidae. Owing to the

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

-like shape of ''Rotularia'', many authors in the past interpreted this genus as being

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

s in the family Vermetidae. All ''Rotularia'' species were cemented to the substrate during their earliest growth stage, but they became detached shortly after the formation of the first whorls (Savazzi, 1995). Their tubes have two layers with different microstructure (Vinn, 2008). This genus is known from the early Kimmeridgian to Late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

(Jäger, 2004).

References

*Jäger, M. 2004. Serpulidae und Spirorbidae (Polychaeta sedentaria) aus Campan und Maastricht von Norddeutschland, den Niederlanden, Belgien und angrenzenden Gebieten. Geologisches Jahrbuch (A) 157, 121–249. *Savazzi, E. 1995. Morphology and mode of life of the polychaete ''Rotularia''. Paläontologische Zeitschrift 69, 73–85. * Serpulidae Prehistoric annelid genera Kimmeridgian genus first appearances Eocene genus extinctions Late Jurassic invertebrates Late Cretaceous invertebrates Paleocene invertebrates Eocene invertebrates Fossil taxa described in 1827 Early Cretaceous invertebrates {{annelid-stub