Hylocitrea

The Hylocitrea, or yellow-flanked whistler, is a unique bird found exclusively in the high-altitude forests of Sulawesi, Indonesia. It's the sole species of its genus and has been linked to the Pachycephalidae family, though new genetic studies suggest it may be more accurately classified under its own subfamily in the Bombycillidae family or even a separate family, Hylocitreidae. A 2019 study discovered that the hylocitrea is closely related to both the hypocolius and the extinct Hawaiian honeyeaters, and these groups together are closely related to the silky-flycatchers. These familial relations date back to the early Miocene epoch, roughly 20-23 million years ago.