Walliserops is a weird genus of lower-to-middle Devonian trilobite with a trident sticking out of its head. There are six species of Walliserops: Walliserops trifurcatus, Walliserops hammii, Walliserops tridens, and three undescribed species.
The use for the trident is unknown. Maybe it's for defense, maybe it's for detecting food under the sand (sort of like a built-in radar), or maybe it's for fighting other males to mate and the female doesn't have a trident, so it might be thought to be a different kind of trilobite.
This well-preserved fossil of Walliserops trifurcatus shows every detail, so scientists don't need to reconstruct it learn about it. Walliserops had to avoid predators such as Shinderhannes bartelsi, Dunkleosteus, Eusthenodon, and Eusthenopteron.
The family of trilobites which was wiped out in the Permian must have been very successful because all other families of trilobites were wiped out in either Ordovician or Devonian.
Walliserops isn't the only trilobite with a weird head. The Permian trilobite Keryopigee had a head shaped like a pointy top hat. But Walliserops probably isn't related to Cheiropyge because Cheiropyge only had one spike in the front of its head. Walliserops had a lot more spikes all over the body.
Walliserops trifurcatus was the only species of Walliserops with a long trident. The others had the trident directly attached to the head and not on a pole-like spike like trifurcatus.