The phylum for invertebrate animals with jointed legs is Arthropoda.

The phylum Arthropoda contains a wide diversity of animals with hard exoskeletons and jointed appendages. Many familiar species belong to the phylum Arthropoda—insects, spiders, scorpions, centipedes, and millipedes on land; crabs, crayfish, shrimp, lobsters, and barnacles in water (Fig. 3.72).

Definitions arthropod - an invertebrate animal of the large phylum Arthropoda, that has an exoskeleton and several pairs of jointed legs, such as an insect, spider, or crustacean. exoskeleton - a rigid external covering for the body in some invertebrate animals, especially arthropods, providing both support and protection.

the statement is true

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.