Multiple choice In which of the following phyla is notochord present? Mollusca Vertebrata Annelida Platyhelminthes Reveal answer Fill a bubble to check yourself B Correct answer Explanation A flexible rod-like structure that is present in the embryos of all chordates and in the adult forms of certain groups, such as the lancelets and hagfishes. The notochord develops into the spinal column in most vertebrates.