They looked something like sheep and something like oxen.
Sometimes they are called musk oxen.
They looked something like the bison.
Sometimes they are called musk bison.
Does it seem strange that the musk sheep should leave their cold home and come to the land where the Tree-dwellers had lived?
It was not so strange as it seemed.
Many years had passed since the Tree-dwellers lived.
It was no longer warm on the wooded hills.
There was snow on the ground the greater part of the year.
After many years it became very cold.