The World on The Turtle's Back

I was kind of skeptical when I first looked at this story. I thought that it was going to be kind of confusing, and honestly a little boring. As I read the World On The Turtle's Back, I did find the story to be very interesting. I enjoyed how the authors described the creation of the Earth, with it all starting as a large ocean. Then the woman fell from the sky world and was placed on the turtle's back by the birds. It was interesting how the woman began to grow plants and create life from this one small clump of dirt that the muskrat retrieved from the ocean's floor. The twins I found to be rather interesting. The idea of the left and right twin to me reminds me of the Chinese idea of Ying and Yang, with one being good and the other being somewhat evil. This is also different though, as the twins were used as the reasoning for different plants and animals. Overall i did really enjoy this story.
Questions
1. Where does the muskrat come from? The muskrat I thought was a land mammal.
2. What happens to the turtle after all this land mass began to grow on his back?
3. How large was the turtle, being he was holding 4 people on his back?