Yarnemia

Yarnemia Temporal range: 557  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
reconstruction as a tunicate-like animal
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Tunicata (?)
Genus:	† Yarnemia Nesov in Chistyakov et al., 1984
Species:	†Y. ascidiformis
Binomial name
†Yarnemia ascidiformis Nesov in Chistyakov et al., 1984

Yarnemia ascidiformis is a fossil tentatively classified as a tunicate. While Y. ascidiformis looks similar to tunicates, the oldest unequivocal tunicate, Shankouclava ^[1] dates to the Cambrian period, while Y. ascidiformis is Ediacaran in age. ^{[2] [3]}

Discovery and name

The holotype fossil of Yarnemia was found from the Ust-Pinega Formation between 1976 and 1978, and described in 1984.

The generic name Yarnemia comes from the village of Yarnema near which the first specimens were found. The specific epithet, ascidiformis, refers to the likeness to ascidians.

Description

Yarnemia ascidiformis is a possible tunicate, growing up to 30 mm (1.2 in) in length, with the standard oblong body and two openings, or siphons, on the top of the body to allow water to flow through them.

See also

Other Ediacaran biota tentatively identified as tunicates include

• Ausia fenestrata
• Burykhia hunti

References

1. Chen, Jun-Yuan, et al. "The first tunicate from the Early Cambrian of South China." Proceedings of the National Academy of Sciences 100.14 (2003): 8314-8318.
2. University of California Museum of Paleontology Berkeley
3. Chistyakov, V.G.; Kalmykova, N.A.; Nesov, L.A. & Suslov, G.A. (1984). "О наличии вендских отложений в среднем течении р. Онеги и возможном существовании оболочечников (Tunicata: Chordata) в докембрии" [On the Presence of Vendian Deposits in the Middle Course of the Onega River and Presumable Existence of Tunica (Tunicata: Chordata) in Precambrian](PDF). Vest. Leningrad. Gos. Univ. (LGU) (in Russian). 6: 11–19. Archived from the original (PDF) on February 7, 2007.