I want to know the answer to the following question:
Which lineage were some of these early marsupial features were lost?
All the background I'm provided with is that "The oldest known fossil among the Eutheria ("true beasts") is the small shrewlike Juramaia sinensis, or "Jurassic mother from China", dated to 160 million years ago in the Late Jurassic.". Is that enough to answer the question?
Answer: no