Waptia fieldensis

Waptia fieldensis is a prehistoric marine arthropod that thrived during the Middle Cambrian period, approximately 505–510 million years ago. It is a cornerstone of the Burgess Shale Lagerstätte, a world-renowned fossil site on Fossil Ridge between Wapta Mountain and Mount Field in Yoho National Park.

Discovery and etymology. Charles Doolittle Walcott discovered Waptia on 31 August 1909 and formally described it in 1912. The genus honours Wapta Mountain (Stoney Nakoda for “river”); the species fieldensis honours Mount Field. Walcott’s field diary includes rough sketches alongside other iconic Burgess Shale fauna such as Marrella and Naraoia.

Morphology. Maximum body length ~8 cm. Shrimp-like overall form. Large bivalved carapace, narrow anteriorly and widening posteriorly, covering the head and most of the thorax. Stalked, reniform compound eyes; long, multi-segmented antennules; five thoracic somites with walking and feeding appendages; five abdominal somites; paired uropods (tail fan) for propulsion.

Taxonomy. Classified as a mandibulate arthropod within Hymenocarina, related to modern crustaceans, insects, and myriapods.

Brood care. Waptia provides the earliest direct evidence of brood care in the animal kingdom. Specimens have been found with clutches of up to 24 eggs preserved between the body and carapace; indicating that adults carried and protected offspring rather than releasing eggs into the water.

Ecology. Inhabitants of a shallow tropical sea adjacent to a submarine limestone cliff (now the Cathedral Formation). Active swimmers; likely predators or scavengers using thoracic appendages to sift detritus and mandibles to manipulate prey.

Wapta vs. Wapiti. The term “Wapta” is often confused with “Wapiti” (elk, Cervus canadensis). Wapiti is Shawnee/Cree for “white rump.” At Lake Louise, tourists who see “Wapta” on trail maps may assume it refers to elk; but the resort’s Wapta run is named for the Wapta Icefield (Stoney for “river”). The fossil Waptia shares the same linguistic root.

Protection. Burgess Shale sites are UNESCO World Heritage protected. Parks Canada and the Royal Ontario Museum monitor the Fossil Ridge locality to prevent fossil theft.