protovertebrate
/ˌprəʊtəʊˈvəːtɪbrət/ /ˌprəʊtəʊˈvəːtɪbreɪt/noun
Zoology. A member of a group of animals from which vertebrates evolved; an animal considered to represent, or to be related to, an evolutionary ancestor of the vertebrates; a very primitive vertebrate.
adjective
Zoology. Of or relating to a protovertebrate or protovertebrates.
Origin
Late 19th century; earliest use found in Theodore Gill (1837–1914). From proto- + vertebrate.