What term describes any animal of the phylum Chordata having a notochord?

The term that describes any animal of the phylum Chordata having a notochord is "Chordate." Chordates are defined by the presence of a notochord, which is a flexible, rod-shaped structure that provides support. In vertebrates, such as mammals, amphibians, and reptiles, the notochord is typically replaced by the vertebral column (spine) during development, but its presence in the early stages is what categorizes these organisms within the Chordata phylum.

Mammals, amphibians, and reptiles are subcategories of chordates; therefore, while they possess specific characteristics that define each class, the overarching term that encapsulates all animals with a notochord is Chordate. This distinction is essential for understanding classifications within the animal kingdom and recognizing the fundamental features that unify members of the phylum Chordata, regardless of their class.