What are invertebrates . Learn their size, lifespan, classification, evolution, and reproduction with pictures. Invertebrate is the group of animals that neither possess a vertebral column nor do they develop a vertebral column in their lifetime. It is derived from the notochord. The Invertebrates animals are different from Vertebrate animals as the Vertebrate animals possess bony or cartilaginous vertebral columns. Among all the living beings, more than 90 percent of living beings are Invertebrates . Invertebrates animals include a diverse group including sea stars, earthworms, jellyfish, sea urchins ... Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a spine or backbone), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum Vertebrata, i.e. vertebrates.
