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.
Flack vs. flak. A flack is a personâespecially a press agent or publicistâwho talks up his or her employer and deflects criticism. Flak (usually a mass noun) refers to (1) antiaircraft artillery, and (2) excessive or abusive criticism (the second definition derives metaphorically from the first).