[2] The extinct species Archotuba elongata is a debated priapulid from the Early Cambrian,[3] discovered by Luo and Hu in 1999.

Recorded only in the Chengjiang Biota of Yunnan Province, this species was initially found to be part of the phylum Priapulida, but some have raised the question that A. elongata may be related to the cnidarians.

[4] In fact, due to the lack of soft body preservation, not only does confusion remain as to the placement of A. elongata, another described species, Archotuba conoidalis, has been found to be a synonym of A.

[4][5] The available specimens consist of hundreds of compressed tubes, white with some rust-colored blotches, each in shape a long cone at most 5 cm in length and 6 mm in width.

[6] The habits of A. elongata are disputable: a popular explanation is that because this species is often found fixed to other creatures, and even clustered together with its own kind in similar orientations, it perhaps did not move, highly unlike the current understanding of priapulids.