[2] Peytoia nathorsti and its junior synonym Laggania cambria played a major role in the discovery of the radiodont body plan.

Initially interpreted as a jellyfish and a sea cucumber respectively, they were eventually shown to be the mouthparts and body of a single animal, which bore Anomalocaris-like appendages.

[1] Another species of Peytoia may be present in the Burgess Shale, represented by a single frontal appendage from the Tulip Beds locality.

[6] The history of Peytoia is entangled with that of "Laggania" and Anomalocaris: all three were initially identified as isolated body parts and only later discovered to belong to one type of animal.

[7] The first was a detached frontal appendage of Anomalocaris, described by Joseph Frederick Whiteaves in 1892 as a phyllocarid crustacean, because it resembled the abdomen of that taxon.

[9][7] Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and frontal appendage represented one enormous creature.

Its discoverer, Kazimiera Lendzion, interpreted it as a member of Leanchoiliidae,[13] a family which now known as part of the unrelated megacheirans (great appendage arthropods).

[20] Aysheaia Onychodictyon Tardigrada Onychophora Megadictyon Jianshanopodia Hadranax Kerygmachela Pambdelurion Utaurora Opabinia Aegirocassis Peytoia Schinderhannes bartelsi Cambroraster Hurdia Amplectobelua Lyrarapax Anomalocaris Houcaris Deuteropoda It has been proposed that the frontal appendages of Peytoia were used to sift sediment for prey, however, some authors have considered this unlikely due to the small size and irregular spacing of the auxiliary spines.