Genus Opisthocomus refers to a group of birds commonly known as hoatzins. These peculiar birds are primarily found in South America, particularly in the Amazon basin. Hoatzins are known for their distinctive smell, which is said to resemble that of cow dung due to their unique digestive system. Synonyms for Genus Opisthocomus include the hoatzin bird, stinkbird, and reptile bird. The name "hoatzin" is derived from the native Quechuan language, which translates to "foul-smelling bird." These birds have a relatively small range and are facing threats from habitat loss and hunting, making conservation efforts critical to their survival.