If that were true, then each pair of twins would be identical with the same embryo. (religion.blogs.cnn.com)
We do not know whether the two ICMs within the same embryo may have originated from uneven splitting of a single «parental» ICM or whether the two ICMs formed independently. (sciencedaily.com)
They produced idential lambs called Megan and Morag, which originated from different cells of the same embryo. (newscientist.com)