Did you know that coelacanths, a living chordate fossil, can live at an ocean depth of 2,300 feet, grow to be 6.5 feet long, and weigh almost 200 pounds? The narrator of a video series on evolution continues his way up the evolutionary ladder in terms of complexity as he explains to viewers the characteristics all chordates have in common–notochord, nerve cord, pharyngeal slits, and post-anal tail. He walks learners through the three subphylum, showing examples of each, and moves on to discuss the remainder of the chordate groups.