Complex sentence: The creature was live-acted by a modern day red-tailed boa, though the episode was set in North America, and "Dinilysia" lived 20 million years before "Tyrannosaurus" and in South America.
Split into simpler sentences: The creature was live-acted by a modern day red-tailed boa. However, the episode in question was set in North America, and "Dinilysia" lived some 20 million years before "Tyrannosaurus" and lived in South America.