Holaspis

Holaspis is a genus of trilobite belonging to the order Phacopida. These extinct marine arthropods lived during the Devonian period. Holaspis is characterized by its distinctive, smooth, and often globular glabella (the central raised portion of the cephalon, or head shield).

The genus is relatively small in size compared to some other trilobites. Holaspis fossils are found in various locations around the world, providing valuable insights into the paleogeography and paleoecology of the Devonian period.

One of the defining features of Holaspis is its enrollment mechanism. These trilobites could tightly roll themselves into a ball for protection, a behavior common among many trilobite species. The smooth exoskeleton and globular glabella aided in this complete enrollment, leaving few vulnerable areas exposed.

The taxonomy of Holaspis can be complex, with several described species. Distinguishing between different species relies on subtle variations in the cephalon, pygidium (tail shield), and overall morphology of the exoskeletal features. Fossil records of Holaspis contribute to a better understanding of the evolution and diversification of trilobites within the Phacopida order.