What is Cloaca?
The '''cloaca''' is a common rear opening in land [[vertebrate]]s. Through this opening, the animals expel [[urine]] and [[faeces]], and carry out [[reproduction]]. The cloaca is a primitive or 'basal' feature of [[tetrapod]]s. All [[amphibia]], all [[sauropsid]]s ([[reptile]]s and [[bird]]s) and even [[monotreme]] [[mammal]]s have a cloaca. A different method is used by [[theria]]n mammals, such as [[marsupial]]s and [[placental]]s. They have an [[anus]] for [[defecation]], and another opening for urine and sexual reproduction. {{biology-stub}} [[Category:Tetrapods]] [[Category:Digestive system]] [[Category:Reproductive system]] [[Category:Animal anatomy]]