There is an article on scala-lang with great diagram (I even put it on the wall). And also need to be mentioned:
If Scala is used in the context of a Java runtime environment, then scala.AnyRef corresponds to java.lang.Object.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…