Chordates

Lancelets are the most primitive chordates.

Keratin is a fibrous protein produced by chordates. It may be found in hair, skin, claws, and wool.

The largest animal phyla are the arthropods, the mollusks, and the chordates.

Humans are chordates.

Chordates are the third largest animal phylum.

All vertebrates are chordates.