They were not designed at random, they were designed with a purpose. He made species fit to live in their environment. He made them able to live through and survive different and varied threats to it. Nevertheless, there are many species which while perfectly fit for their environment exhibit features which in no way they could have inherited through evolutionary means. I show those creatures which I am sure could not have developed through evolutionary means in the article above and give links showing why they are so unique. I am sure there are many more of which I do not know about.
So extinct species represent what? Failures of the Creator? I don't think so.
Maybe failure of your theory? Species were designed to fail?