Which of the follwing is not present at birth?
Ans: D (Petrous part of the temporal bone) Ref: Grays Anatomy 40th Ed Explanation: Ear ossicles will be completely formed before birth Development of Temporal Bone In the neonate, the petrous and squamous parts of the temporal bone are usually partially separated by the petrosquamous fissure This opens directly into the mastoid antrum of the middle ear The fissure remains open till 20 years in 20-40% individuals
Malleus
Incus
Stapes
Petrous part of the temporal bone