In the base of the skull, which of the following foramen is most anteriorly placed?
The foramina in base of skull, in an order from anterior to posterior

Foramen ovale.
Canaliculus innominatus (sometimes)
Foramen spinosum.
Carotid canal.
Jugular foramen.
Stylomastoid foramen.

Sometimes, emissary sphenoidal foramen or foramen of Vesalius is situated between foramen ovale and scaphoid fossa in base of skull view - norma basalis.
On the internal surface of base of skull, it opens between foramen rotundum and foramen ovale.
Stylomastoid foramen
Foramen spinosum
Foramen ovale
Juglar foramen