Phylum Chordata

Chordata

Phylum Chordata:

1) Subphylum Protochordata
2) Subphylum Vertebrata

Protochordata:

1. This animals are billaterally symmetrical, triploblastic and have a coelom.
2. In addition, they show a new feature of body design, namely a notochord, at least at some stages during their lives.
3. The notochord is a long rod-like support structure that runs along the back of the animal separating the nervous tissue from the gut.
4. It provides a place for muscles to attach for ease of movement.
5. Protochordates may not have a proper notochord present at all stages.
6. Protochordates are marine animals.
7. Examples- Balanoglossus, Amphioxus.
   

Vertebrata:

1. These animals have a true vertebral column and internal skeleton allowing a completely different distribution of muscle attachment points to be used for movement.
2. Vertebrata are bilaterally symmetrical, triploblastic coelomic and segmented, with complex differentiation of body tissue and organs.
3. There is five classes of this subphylum i.e Pisces, Amphibia, Reptilia, Aves, Mammalia.

Aves