The upcoming discussion will update you about the difference between prototheria and theria. Difference # Prototheria: 1. Eggs or Young ones : Oviparous 2. Mammary: Mammary glands are without nipples or teats. 3. Glands: Indistinct or absent. 4. Pinna: Present and is formed by the nasal and premaxilla bones. 5. Beak Cloaca or anus: Cloaca […]