cranial nerve development olfactory nerve development GO:0021553 CN 1 development The process whose specific outcome is the progression of the olfactory nerve over time, from its formation to the mature structure. The olfactory nerve is a collection of sensory nerve rootlets that extend down from the olfactory bulb to the olfactory mucosa of the upper parts of the nasal cavity. This nerve conducts odor information to the brainstem. cranial nerve I development cranial nerve 1 development biological_process