In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive and urinary tracts of certain animal species. The word comes from Latin, and means sewer. All birds, reptiles, and amphibians possess this orifice, from which they excrete both urine and feces, unlike placental mammals, which possess two separate orifices for evacuation. The cloacal region is also often associated with a secretory organ, the cloacal gland, which has be… (More on Cloaca)