Over the last 100 odd years, the evolution of birds was marked by the eventual loss of all teeth. How and why this happened is still being discovered. In the process, however, some birds have developed unusual tooth-like serrated jaws, and the functions of these are peculiar to the birds in question. Toucans, hummingbirds, mergansers, even some raptorial birds such as osprey, and some extinct birds have developed large toothy projections, but most of these birds lack bony parts. Some that do, such as mergansers, an extinct group of ducks from the Pacific called moa-nalos, and the incredible pelagnornithid "pseudontorns" have remarkable bony projections, the function of which in some are unknown due to their disappearance. More here: qilong.wordpress.com/2014/10/2…
- Pelagornis sandersi
, the largest soaring bird known, and second largest flying bird after Argentavis</i>.Middle
- Hesperornis regalis
, a diving and flightless bird once considered a relative of loons and grebes. Naturally, bore teeth in its jaws, these are shown covered up with featherless soft-tissue.Bottom
- Mergus merganser
, specifically a male red-breasted merganser.