|Named By:||Charles Doolittle Walcott in 1919|
|Time Period:||Chengjiang-Burgess Shale|
|Location:||Canada - Burgess Shale. China, Chengjiang. USA, Utah|
|Size:||Up to 3 centimetres across|
|Fossil(s):||At least 23 individuals|
|Classification:||| Animalia | Hemichordata | Pterobranchia ||
Yuknessia is an early pterobranch, known from the Burgess shale, the Chengjiang and the Wheeler shale. Long, unbranched fronds emerge from a central holdfast-like body covered in small conical plates. 23 specimens of Yuknessia are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. The genus contains two species: the type species Y. simplex and Y. stephenensis It was originally interpreted as a green alga, and has since been reinterpreted it as a colonial pterobranch.