Yuknessia

Yuknessia Temporal range: Chengjiang–Burgess Shale PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Hemichordata
Class:	Pterobranchia
Genus:	Yuknessia Walcott, 1919
Species
Y. simplex Walcott, 1919 (type) Y. stephenensis LoDuca et al., 2015

Yuknessia is an early pterobranch, known from the Burgess shale,^[1] the Chengjiang and the Wheeler shale.^[2] Long, unbranched fronds emerge from a central holdfast-like body covered in small conical plates.^[1] 23 specimens of Yuknessia are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community.^[3] The genus contains two species: the type species Y. simplex and Y. stephenensis^[2] It was originally interpreted as a green alga, and has since been reinterpreted it as a colonial pterobranch.^[2][4][5]

External links

• "Yuknessia simplex". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011.

References

1. Briggs, D.E.G.; Erwin, D.H.; Collier, F.J. (1995), Fossils of the Burgess Shale, Washington: Smithsonian Inst Press, ISBN 1-56098-659-X, OCLC 231793738
2. Steven T. LoDuca, Jean-Bernard Caron, James D. Schiffbauer, Shuhai Xiao and Anthony Kramer (2015). "A reexamination of Yuknessia from the Cambrian of British Columbia and Utah". Journal of Paleontology. 89 (1): 82–95. doi:10.1017/jpa.2014.7.
3. Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.
4. Michael Steiner & Jörg Maletz (2012). "Cambrian graptolites (Pterobranchia) and the origin of colonial organization in metazoans" (PDF). TERRA NOSTRA – Schriften der GeoUnion Alfred-Wegener-Stiftung. Centenary Meeting of the Paläontologische Gesellschaft. Programme, Abstracts, and Field Guides. 2012/3: 173–174.
5. "Graptolite (Hemichordata, Pterobranchia) preservation and identification in the Cambrian Series 3". doi:10.1111/pala12200 (inactive 2016-06-17).