Protochordata

• These animals are bilaterally symmetrical, triploblastic.
• They show a new feature of body design, namely a notochord , at least at some stages during their lives.
• The notochord is a long rod-like support structure (chord=string) that runs along the back of the animal separating the nervous tissue from the gut.
• It provides a place for muscles to attach for ease of movement.
• Protochordates may not have a proper notochord present at all stages in their lives or for the entire length of the animal.
• Protochordates are marine animals.

For Example: Balanoglossus, Herdmania and Amphioxus