Oldest part of the cerebellum (present even in fish) is the flocculonodular lobe consisting of the nodule of the vermis and the flocculus in the hemisphere on each side

More recent is the anterior lobe and contains the pyramis and the uvula

Most recent is the posterior lobe • The tonsils lie directly above the foramen magnum of the skull • If the intracranial pressure is raised (e.g., by a brain tumour), one or both tonsils may descend into the foramen and pose a threat to life by compressing the medulla oblongata