Template:Early Neural Timeline table

Carnegie stage 8 - (about 18 postovulatory days) neural groove and folds are first seen

• Carnegie stage 9 - the three main divisions of the brain, which are not cerebral vesicles, can be distinguished while the neural groove is still completely open.
• Carnegie stage 10 - (two days later) neural folds begin to fuse near the junction between brain and spinal cord, when neural crest cells are arising mainly from the neural ectoderm
• Carnegie stage 11 - (about 24 days) the rostral (or cephalic) neuropore closes within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in several areas simultaneously. The two lips, however, behave differently.
• Carnegie stage 12 - (about 26 days) The caudal neuropore takes a day to close.
  • the level of final closure is approximately at future somitic pair 31.
  • corresponds to the level of sacral vertebra 2.
• Carnegie stage 13 - (4 weeks) the neural tube is normally completely closed.

Secondary neurulation begins at stage 12 - is the differentiation of the caudal part of the neural tube from the caudal eminence (or end-bud) without the intermediate phase of a neural plate.

Human Shoulder Development
Stage	Event