''Glomerula'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

polychaete worm 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 made ...

in the family

Sabellidae Sabellidae, or feather duster worms, are a family of marine polychaete tube worms characterized by protruding feathery branchiae. Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell. Unlike the ...

. It differs from all other Sabellidae in having a calcareous tube and spinose

setae In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

. Only one living species, ''G. piloseta'', is known from

Lizard Island Lizard Island is an island on the Great Barrier Reef in Queensland (Australia), northwest of Brisbane and part of the Lizard Island Group that also includes Palfrey Island. It is part of the Lizard Island National Park. Lizard Island is within ...

, Great Barrier Reef, Australia. The oldest fossils of ''Glomerula'' are known from the Early

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

and their tube microstructure has remained unchanged since then.

References

{{Taxonbar, from=Q2153277 Sabellida Extant Early Jurassic first appearances