How did *Wiwaxia*'s armor structure differ fundamentally from typical mollusks?

It was clad in hundreds of individual, articulating pieces of armor rather than possessing a single hard shell or bivalve structure.

A major point of confusion and debate regarding *Wiwaxia*'s classification stemmed from its protective covering, which contrasted sharply with the standard morphology of modern mollusks like snails or clams. Typical mollusks rely on a unified structure, often secreted as a single shell or pair of hinged shells (bivalves). In contrast, *Wiwaxia* featured a highly dispersed armor system composed of hundreds of separate, small, dermal elements—the sclerites—that could shift and articulate as the animal moved. This architecture, relying on numerous small dermal ossifications rather than one large, centralized shell, represented a unique evolutionary pathway, even if *Wiwaxia* shared distant ancestry with mollusks.