Arthropods are the largest and most diverse phylum of the animal kingdom. It includes, among others, insects, arachnids, crustaceans and myriapods. The term is applied to invertebrate animals equipped with an external skeleton and jointed appendages, such as crustaceans, insects, and spiders.
An Arthropleura and a colony of Carboniferous Arachnids came through an Anomaly into the London Underground in the present day. The Arachnids were driven back through the Anomaly, and the Arthropleura was killed by electrocution.
The ARC team and Taylor Craig encountered Silurian Scorpions and Millipedes in the Silurian, and the Scorpions were responsible for the deaths of the Cleaner and two other mercenaries in the Silurian.
An Arthropleura and three Silurian Scorpions were captured by Oliver Leek's organisation and placed in his Creature Prison. One of the Scorpions was released onto a beach and presumably captured and taken in by the Anomaly Research Centre, and the other two Scorpions and the Arthropleura were presumably killed after they were locked in the Prison's cage room with the other creatures.
Two Megopterans (giant Future arthropods descended from Hymenoptera) came through an Anomaly to a Race Circuit in the present day, were one was run over and killed by a car, and the other seemed to go back through the Anomaly. In the desolate Future City on the other side of the Anomaly, several Megopterans fought in the streets with Future Predators.
A colony of approximately fifty Giant Burrowing Insects came through an Anomaly to London at some point pre-2011. One of the Insects died of gunshot wounds to the face, and the rest of the colony was killed by a gas explosion.
A swarm of Jurassic Beetle drones attacked Jim's plane in a Jurassic Desert. A queen Beetle also came through an Anomaly to Spring River Airport in the present day; it was ultimately sent back through the Anomaly.