Wiwaxia

Wiwaxia is an extinct genus of marine animals from the Cambrian Period, recognized by overlapping armor-like scales and paired dorsal spines.

Cambrian: The first period of the Paleozoic Era, spanning roughly 539 to 485 million years ago. Wiwaxia fossils occur in deposits from this interval.
Sclerite: A small, hardened plate or spine forming part of an animal’s external covering. Wiwaxia’s overlapping scales are sclerites arranged in distinct body zones.
Charles Doolittle Walcott: An American geologist and paleontologist who discovered and studied the Burgess Shale fossils. Walcott described Wiwaxia from the Burgess Shale in the early twentieth century.
Mollusca: A major animal phylum that includes snails, clams, and cephalopods. Wiwaxia’s radula-like feeding apparatus and scales have been compared with molluscan features.
Phylogenetic placement of Wiwaxia: The unresolved question of where Wiwaxia belongs on the evolutionary tree of animals. Molluscan and annelid affinities explain different parts of its anatomy.
Burgess Shale: A fossil deposit in British Columbia that preserves exceptional soft-bodied Cambrian organisms. Its fossils provide the best-known record of Wiwaxia.
Radula: A ribbon-like feeding organ bearing rows of tiny teeth, found in molluscs and some related animals. A fossilized radula associated with Wiwaxia suggests it scraped or processed food.
Harry B. Whittington: A British paleontologist whose research transformed understanding of Burgess Shale animals. His reexamination of Wiwaxia helped establish its distinctive body anatomy.
Annelida: A phylum of segmented worms, including earthworms and marine bristle worms. Some interpretations link Wiwaxia’s body organization and bristles to annelid-like animals.
Cambrian paleontology: The study of Cambrian fossils and the evolution of early animal ecosystems. New fossils and analytical methods may clarify Wiwaxia’s anatomy and relationships.

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OttoiaRelated: Wiwaxia remains in Ottoia fossils provide direct evidence of predation.