Thank you, Glen. My brain keeps remembering this word "childlike" and that was why I asked. Also I am looking for some adjectives to describe a turtle shell. Since people don't normally use it, I will not use it either.It makes sense -- you can understand it -- but it is awkward and not what we would normally say.
Thank you, Ed. Glen in post #2 said that it is not common that people use the word "shield-like". So I don't think I will use that word. However, I really like your reassurance that I can use it.In your original sentence it's better to say that the shell is like a shield, but you could use shield-like as an adjective if you wanted so say something else about the shell, for example:
The turtle's shield-like shell is strong enough that you can stand on it without danger of squashing the turtle. -- This is a hypothetical example, don't say this to anyone and then blame me if it goes horribly wrong!