What is the difference between vertebrates or invertebrates?
Vertebrates are animals with a backbone (a connected stack of bony segments, each called a vertebra — plural: vertebrae). Vertebrates represent the majority of Chordates, which is a phylum of the animal kingdom — a main category. Any animal other than a chordate is an invertebrate because it belongs to a different phylum (with a few exceptions such as lancets). Other phyla include arthropods (insects, lobsters, etc.); mollusks (snails, squid, etc.); sponges; sea stars; worms; etc. Vertebrates are subdivided into fish, amphibians, reptiles, birds, and mammals. If it’s not one of those it’s probably an invertebrate. Vertebrates have an endo-skeleton made of bone or cartilage. Invertebrates have no skeleton or an exo-skeleton. Vertebrates have a head containing a brain, which continues as a spinal cord into the backbone. The various nervous systems of invertebrates are organized differently.
