Key Characteristics

Key evolutionary innovation: Notochord

• Deutrostome coelomates
• Internal endoskeleton
• Notocord: flexible rod
• Develops along the back of the embryo
• Species diversity: 56,000 species

All chordates have these characteristics during sometime in the their life, specifically as an embryo or larva. 

• Notochord
• Dorsal hollow nerve cord
• Pharyngeal pouches
• Postanal tail
• Vertebrates
• Backbone
• Skull protecting a brain