(...) at some stage of its development, every chordate exhibits five uniquely derived characters or synapomorphies of the group: (...) (4) a single, tubular nerve cord that is located dorsal to the notochord (...).[well established][VHOG]

TODO - add grouping class for the anterior end of the neural tube at all stages

uberon

UBERON:0003080

• anterior neural tube closure

• presumptive midbrain
• forebrain

• midbrain neural tube