‖n. pl. [ NL., fr. L. in- not + vertebratus vertebrate. ] (Zool.) A comprehensive division of the animal kingdom, including all except the Vertebrata. [ 1913 Webster ]
a. (Zool.) Destitute of a backbone; having no vertebræ; of or pertaining to the Invertebrata. --
Age of invertebrates.
a. Having no backbone; invertebrate. [ 1913 Webster ]
‖n. pl. [ NL. ] (Zool.) One of the grand divisions of the animal kingdom, comprising all animals that have a backbone composed of bony or cartilaginous vertebrae, together with Amphioxus in which the backbone is represented by a simple undivided notochord. The Vertebrata always have a dorsal, or neural, cavity above the notochord or backbone, and a ventral, or visceral, cavity below it. The subdivisions or classes of Vertebrata are Mammalia, Aves, Reptilia, Amphibia, Pisces, Marsipobranchia, and Leptocardia. [ 1913 Webster ]
n. (Zool.) One of the Vertebrata. [ 1913 Webster ]