syrinx:
But the earliest syrinx, an arrangement of vibrating cartilage rings at the base of the windpipe, was still a long way from producing the lilting notes of a blackbird. Instead, the extinct duck relative that possessed the organ between 66 and 69 million years ago was only capable of honking (Nature, doi.org/brvv).
NewScientist, “First birds made honking sounds more than 66 million years ago” (22 October 2016)
