Subarcuate fossa

The subarcuate fossa is a shallow  depression upon the internal surface of the petrous part of the temporal bone forming the wall of the posterior cranial fossa. The fossa accommodates the flocculus of the cerebellum. It is situated lateral/posterior to the internal auditory meatus. 

Anatomy
The subarcuate fossa is situated posteriorly and superiorly  between the opening of the vestibular aqueduct and opening of internal auditory meatus.

The surface of the subarcuate fossa is lined with dura mater and lodges the endolymphatic sac and duct, as well as a minute artery and vein; some veins from the mucosa of mastoid antrum enter the cranial cavity at the subarcuate fossa to drain at the superior petrosal sinus - they are remnants of larger subarcuate veins of childhood and represent a possible route of intracranial infectious spread.

Other animals
It is extensive in most primates (except for great apes) and nearly all mammals. In these animals, the subarcuate fossa houses a part of the cerebellum, the petrosal lobe.