''Strenuaeva'' is a genus of Cambrian trilobite thought to show

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

References

Ptychopariida genera Cambrian trilobites Fossils of Sweden {{Ptychopariida-stub