A new enantiornithine from the Yixian Formation with the first recognized avian enamel specialization

We report on a new enantiornithine bird, Sulcavis geeorum, gen. et sp. nov., from the Jehol Group of northeastern China. The fossil preserves robust teeth with longitudinal grooves radiating from the occlusal tip preserved in the enamel on the lingual surface. This is the first known occurrence of specialized tooth enamel within Aves. Compared with other Mesozoic groups, stomach contents are hardly ever preserved within enantiornithine...