The buttonquails or hemipodes resemble, but are unrelated to, the true quails.
The buttonquails or hemipodes are a small family of birds which closely resemble true quails, but are unrelated to them.
Also called a hemipode, it resembles a true quail in appearance and way of life but is more closely related to sandgrouse and pigeons.
There's a slim chance of picking up Madeiran petrel on my forthcoming Canaries trip, and I now know of a site in Morocco where the hemipodes are said to be still present and calling.
Origin
Mid 19th century: from modern Latin Hemipodius (former genus name), from Greek hēmi- 'half' + pous, pod- 'foot'.