Thaumactena

Thaumactena is an extinct monotypic genus of scleroctenophoran that lived during Cambrian Stage 3, around. The type and only species is Thaumactena ensis.

Description

Two specimens are known, the holotype, and the paratype, both having a length-width ratio of 10:1. The oral region expands outward, forming an "oral skirt." Thaumactena is distinguished from other scleroctenophorans by the possession of a streamlined body, similar to chaetognaths, suggesting that, in life, it was an agile swimmer.

Phylogeny

Thaumactena is placed in the Scleroctenophora, as it and other members of the class possess an internal skeleton.