How snakes yawn.
Round Island Boa (Casarea dussumieri)
Also known as the Round Island Keel-scaled Boa, the Round Island boa is an endangered species of Bolyeriid snake that is endemic to Round Island, Mauritius. However, it has been recorded on the islands of Gunner’s Quoin, Flat Island, and IIe de la Pas as well. Round Island boas are unique among vertebrates in that they have a split jaw (an intramaxillairy joint that separates anteria and posteria bones). This is likely an adaptation which helps C. dussumeireri catch its prey, which consists mainly of geckos and skinks.
Currently C. dussumieri is listed as Endangered and faces threats from not only a small range but habitat loss and decrease of prey items as well.