arthropoda
Structures
Arthropods have segmentation, they have a head thorax and abdomen, some have a cephalothorax where the head and thorax are combined. they can also have a variety of respiratory systems including, gills, tracheal tubes, or book lungs
Classes.
Chelicerata
Under the phyla Arthropoda ther is the subphyla Chelicerata, they are named after their fangs called chelicerae. Examples od this subplyla are merostomata (Horseshoe crabs) and Arachnida (Spiders, Scorpions, ticks, Mites)
Uniramia
Another subphyla under Arthropoda is Uniramia, this subphyla includes Millipedes, and Chilopoda (centipedes), and other insects
Crustacea:
The last subphyla under Arthropoda is the subphyla Crustacea, it includes crustaceans such as crayfish, lobsters, crabs, and shrimp.