See text Tuzoia (from Mount Tuzo, a mountain in the Canadian Rockies) is an extinct genus of large bivalved arthropod known from Early to Middle Cambrian marine environments from what is now North America, Australia, China, Europe and Siberia.

However, the soft tissues described in 2022 suggest an alternative interpretation as an animal that swam close to the seafloor (nektobenthic) as a predator or a scavenger.

[1] They were formerly considered to be the only members of the family Tuzoiidae until 2022, when a new genus Duplapex was described from the Cambrian of China, which differs from Tuzoia by having a flat carapace.

Their phylogenetic position was long uncertain due to the lack of soft tissue remains, a close relationship with Isoxys was proposed based on similarities of their carapaces.

Phylogeny of Hymenocarina after Izquierdo-López and Caron (2024)[11]Tuzoia Perspicaris Pectocaris Loricicaris Tokummia Branchiocaris Plenocaris Ercaicunia Clypecaris Pauloterminus Canadaspis Waptia Chuandianella Vermontcaris Odaraia Jugatacaris Fibulacaris Pakucaris Balhuticaris Nereocaris