Why is the anaconda in the chordata phylum?

Answer 1

To answer the question in the simplest way, the anaconda has a backbone.

However, there is more to it than that, especially given that there are two invertebrate chordate groups - Urochordata (tunicates) and Cephalachordata (lancelets) - whose backbone is not in the form of actual vertebrae.

As Chordates (or members of the phylum Chordata), anacondas share the following characteristics:

• dorsal nerve cord which is a bundle of nerve fibres which runs down the back. It connects the brain with the lateral muscles and other organs.
• notochord which is a cartilaginous rod running underneath, and supporting, the nerve cord - in the case of the anaconda, a spine.
• post-anal tail - an extension of the body past the anal opening. (This feature is not always present in some adult Chordates such as frogs and humans, but it is present in the anaconda.)
• Pharyngeal pouches - Chordates, at some stage of their life, have pharyngeal grooves and pouches that develop into other essential parts of their anatomy.