Section 2 â¢ Invertebrate Chordates 803 Chordates are animal s belonging to the phylum Chordata (kor DAH tuh) that have four distinctive featuresâa dorsal tubular nerve cord, a notochord, pharyngeal pouches, and a postanal tailâat some point during their development.ost chordates are vertebrates. Invertebrate chordates, which belong to two of the subphyla of chordatesâCephalochordata and Urochordata, also have a dorsal tubular nerve cord, a notochord, pharyngeal pouches, a postanal tail, and, possibly, an ancestral thyroid gland. They ha ve no backbone, however.
quack 1. (kwÄk) n. The characteristic sound uttered by a duck. intr.v. quacked, quackÂ·ing, quacks. To utter the characteristic sound of a duck.
Definition of shuck. 1 : shell, husk: such asa : the outer covering of a nut or of an ear of cornb : the shell of an oyster or clam.