How the classification phylum Chordata is organized into subphylums?

Answer 1

There are three surviving subphylums of Chordata. The first, which branches off earliest, is called Urochordata and contains tunicates. The other two branches fork later, and are the Cephalochordata (amphioxus/lancelets) and Craniata (all vertebrates).

Answer 2

The phylum Chordata is organized into three subphyla: Urochordata (tunicates), Cephalochordata (amphioxus), and Vertebrata (vertebrates). These subphyla are distinguished by specific characteristics, such as the presence or absence of a backbone, which differentiate them within the larger phylum Chordata.