This is a very interesting question and it depends largely on definitions. Even the word hominid has varying meanings depending on who you ask varying from strictly meaning the ancestors of humans over the last 4 million years to encompassing all of the great apes (humans, chimpanzees, gorillas, and orangutans).

As you get evolutionarily closer to modern humans where we diverge from the rest of the great apes, there is still some controversy over who we're descended from. Much of this difficulty arises from the fact that we have only a limited number of bones from these ancestors and frequently, each one seems to indicate some new branch of our genetic tree. There may yet be other bones out there waiting to be discovered and tell more of the story.

A very good website for further explanation of human evolution is the Smithsonian. It poses what we know with pictures of the fossil remains and it also tells about some of the controversies. smithsonian