It is a soft invertebrate without eyes or teeth. However, invertebrate Amphious (and especially Blanchiostoma floridea) can explain the origin of vertebrates. This species had a rope in the back, that is, precursor of the spine, so it is believed that it was the common anchor of all current vertebrates, including humans.
However, the problem has become of great interest in the discovery made in recent times by researchers experts in genetics, Jordi Garcia-Fernandez and Peter Holland. Invertebrate has been found with genes called Homeobox (which determine the anatomical organization of the being) and are equivalent to those of vertebrates.