Given the question: I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "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. A later eutherian, Eomaia, dated to 125 million years ago in the Early Cretaceous, possessed some features in common with the marsupials but not with the placentals, evidence that these features were present in the last common ancestor of the two groups but were later lost in the placental lineage. In particular:"?
The answer is:
Which came after, the placentals, or the last common ancestor?