Creationists are fond of claiming that there is a lack of transitional fossils. Well here is another one:
Scientific American: From Jaw to Ear: Transition Fossil Reveals Ear Evolution in Action
Now hear this: early mammal fossil shows how sensitive ear bones evolved.
As Larry Martin said in response to creationist claims: "My drawers are crawling with transitional forms-" uh, meaning his fossil storage drawers of course.