The Chordates are animals that comprise the phylum Chordata. Taxonomically the phylum Chordata includes three subphyla: Tunicata; Cephalochordata, comprising the lancelets; and the Craniata, or Vertebrata. The common attributes of the Chordata include having, for at least some period of their life cycles, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail. The phylum Hemichordata has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum.