Need help with the following clues please.
9A:Building material easily eroded S?N?????E (9)
5D: In certain though not fast way S????? ??T ?????? (6-3-6) sorry for lack of letters.
14D: Very severe D?A???I?? (9)
16D: With flat sections between ??T?????D (9)
26A: Herbivorous dinosaur S???????R (9)
Thanks in advance.