In the Carnegie Stage, the proximal part of the notochordal canal persists temporarily as the neurenteric canal ( also known as the " axial canal " ), which forms a transitory communication between the amniotic sac and the yolk sac cavities.
2.
UMZC T836 was likely not a neurocentral sutures, but possibly also not fully-grown, as in at least some elements like the fifth vertebra, the notochordal canal is still connected to the neural canal through an hourglass-shaped opening.