Which bird has a structure "Donitz’s bridge" in its neck?

The Indian darter or oriental darter is like all other anhingas, a cormorant-like species that has a very long neck. The structure of the neck is as in other species of darter with strongly developed muscles about a kink in the neck at the 8th and 9th vertebrae that allows it to be flexed and darted forward with rapid force to stab fish underwater. The fibrous representative of Donitz's bridge is seen attached to the ninth cervical vertebra.