Carnegie Stage 12 Definition

Age is approximately 26 postovulatory days

Length is approximately 3-5 mm

External Features Include: a characteristic curved posture, three pharyngeal arches are visible, the caudal neuropore is closing or closed; the otic vesicles are almost closed but not detached; the upper limb buds are beginning to appear.


(O'Rahilly R and Muller F [1987] Developmental Stages in Human Embryos. Carnegie Institute, Washington, Publication no. 637)