How did the mammalian reproductive system develop from Monotremata over Marsupalia to Mammalia?

Answer:
The question asked is wrong, this process is called evolution not development & it did not happened as you asked ,monotremata and marsupials are both mammals
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First answer by Profmafzal. Last edit by Profmafzal. Contributor trust: 31 [recommend contributor recommended]. Question popularity: 1 [recommend question].