Difference between Prototheria and Theria are given below:
1. External ear on pinnae is absent.
2. Teeth are absent in the adult condition.
3. Cloaca is present.
4. Mammary gland is present but nibble is absent.
5. Testes are abdominal.
6. Corpus collasm absent.
7. Egg laying animals.
1. External ear pinnae are present.
2. Teeth are well developed.
3. Cloaca is absent.
4. Mammary gland is present with nipple.
5. Tests are descending in to scrotal sac.
6. Urethra is common for vasa differentia and urinary bladders.
7. Viviparous animals.