Which preposition to use with dewlap

beneath Occurrences 1%

It was a sinister but powerful face, the face of a debauched hero, clean-shaven, strongly eye-browed, keen-eyed, with huge, aggressive jaw, and an animal dewlap beneath it.

of Occurrences 1%

The Commodore accordingly attempted to grasp his arm, which he found as solid as it was huge, and then passed his hand over the monstrous neck, which fell in folds of massive flesh, like the dewlap of a prize ox.

on Occurrences 1%

There should be plenty of loose, thick, and wrinkled skin about the throat, forming a dewlap on each side from the lower jaw to the chest.

under Occurrences 1%

This pendulous gland is long and narrow in the young hull, but as he ages it shortens and widens, becoming eventually a sort of dewlap under the throat.

Which preposition to use with  dewlap