Why are lobsters invertebrates?

An American lobster photographed in Lincoln, Nebraska Photograph by Joel Sartore, National Geographic Photo Ark. Common Name: American Lobster. Scientific Name: Homarus americanus. Type: Invertebrates. Diet: Omnivores. Average life span in The Wild: 50 or more years. Size: Up to 3.25 ft long. read more

Because when the first bilateral organism emerge (which evolve from radial organism like jellyfish), arthropods (like lobsters) follows a different evolutionary pathway to vertebrates. read more

An invertebrate, they have a carapace not a spine. Vertebrates - animals with backbones - are a subset of the chordates (animals with a stiff rod along the back), and include fish, amphibians, reptiles, birds and mammals. All other multicelled animals, including lobsters, are invertebrates, including lobsters. read more

Lobsters are marine invertebrates, the group of animals without a notochord. Like many invertebrates, lobsters protect themselves with their hard exoskeleton. This exoskeleton provides structure to the lobster's body. read more