Invertebrates are animals that lack a backbone. Invertebrates account for more than 97% of all species alive today.
The first animals to have evolved were invertebrates.
Fossil evidence of invertebrates dates back to the late Precambrian, 600 million years ago. Invertebrates evolved from single-celled microorganisms.
Since invertebrates do not have bones, a bony skeleton, or a backbone, they must instead gain structural support for their bodies in different ways.
|Marine||Marine Habitats • Aquariums • Global Oceans • Ocean Weather
|Vertebrate||Fishes • Mammals • Reptiles • Amphibians • Cartilaginous Fishes • Sharks
|Invertebrate||Arthropod • Mollusca • Echinoderms • Cnidaria
|Conservation Status||Critically Endangered • Endangered • Near Threatened • Vulnerable • Least Concern • Data Deficient • Not Evaluated|