<h2>Chordata</h2>

<p>
Chordates (/ˈkɔrdeɪts/) are animals possessing a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a 
post-anal tail for at least some period of their life cycles. Taxonomically, the phylum includes the subphyla Vertebrata, including 
mammals, fish, amphibians, reptiles, birds; Tunicata, including salps and sea squirts; and Cephalochordata, comprising the lancelets. 
Members of the phylum Chordata are bilaterally symmetric, deuterostome coelomates, and the vertebrate chordates display segmentation.
</p>
<p>
The phylum Hemichordata including the acorn worms has been presented as a fourth chordate subphylum, but it now is usually treated as a 
separate phylum. It, along with the phylum Echinodermata, including starfish, sea urchins, and sea cucumbers and their kin, are the 
chordates' closest relatives. Primitive chordates are known from at least as early as the Cambrian explosion.
</p>

<p>
Of the more than 65,000 living species of chordates, about half are bony fish of the class Osteichthyes. The world's largest and
 fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans.
</p>