Peytoia nathorsti
Peytoia nathorsti is a species of hurdiid radiodont from the Burgess Shale. It is the type species of the genus "Peytoia". History. Like the iconic Burgess Shale radiodont "Anomalocaris canadensis", "Peytoia nathorsti" has a complicated taxonomic history. It and "Laggania cambria" were named in the same paper in 1911. The type specimen of "Peytoia nathorsti" consisted of an isolated oral cone, which Walcott interpreted as the body of a jellyfish. The type specimen of "Laggania cambria" was a poorly preserved body and oral cone, which Walcott interpreted as being a holothurian. In 1978, however, Simon Conway Morris recognized  that the "mouthparts" of "L. cambria" were nearly identical to the "body" of "P. nathorsti", so he suggested that "L. cambria" was a composite of a sponge, "Corallia undulata", and a "Peytoia nathorsti". Conway Morris regarded "Laggania cambria" as a synonym of "Peytoia nathorsti", and in doing so made "Peytoia nathorsti" be the valid name among the simultaneously-named synonyms. In 1985, Harry B. Whittington and Derek E. G. Briggs described the first full-body specimens of "Peytoia nathorsti" along with the first full-body specimen of "Anomalocaris canadensis". Based on the newly apparent similarities between the two species, they  considered "P. nathorsti" to be a species of "Anomalocaris", as "Anomalocaris nathorsti". Finally, new data on the morphology of the oral cone of" Anomalocaris canadensis" in 2011 confirmed that it was distinct from "Peytoia nathorsti".