Animals with a backbone are called vertebrates. Animals without a backbone are called invertebrates. Vertebrates and invertebrates can be sorted into smaller groups. Vertebrates, for example ...

uterine and smooth), from lower classes within the vertebrate phylum (amphibian, fish and cyclostome) and from representatives of different invertebrate phyla (arthropod, mollusc, echinoderm ...

Vertebrates are animals that have a backbone inside their body. The major groups include fish, amphibians, reptiles, birds and mammals. Invertebrates don't have a backbone. They either have a soft ...