Chordates

Non-chordates

Notochord is present.

Notochord is absent.

Central nervous system is hollow, single and dorsal.

Central nervous system is solid, double and ventral.

Pharynx perforated by gill slits.

Gills are not present.

Heart is ventral.

Heart, if present is dorsal.

A post-anal part(tail) is present.

A post-anal part(tail) is absent.