''Hyolithellus'' is a conical tubular fossil from the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

, originally considered a

hyolith Hyoliths are animals with small conical surface, conical animal shell, shells, known as fossils from the Palaeozoic era. They are at least considered as lophotrochozoan, and possibly being lophophorates, a group which includes the brachiopods, w ...

but since reinterpreted tentatively as an

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

worm. Its circular, thin (15–150 μm), originally phosphatic tube gets wider along its long, undulating, annulated length.

References

Cambrian invertebrates Prehistoric annelid genera Paleontology in Washington (state) Paleozoic life of New Brunswick Paleozoic life of Newfoundland and Labrador Paleozoic life of the Northwest Territories Paleozoic life of Nova Scotia Paleozoic life of Quebec Cambrian genus extinctions {{cambrian-animal-stub