Let’s get one thing clear. There is no missing link. Though the term “missing link” has currency with the public and pundits (not to mention creationists), to professionals and paleoanthropologists, it is a myth!
“The Missing Link” is a common phrase that causes mass confusion. It also gives rise to two major misconceptions:
First, the phrase leads directly to a profound misunderstanding of the world of living things because it promotes an essentially medieval view of nature, one in which species are fixed “types,” or “links,” that don’t change through time. To have a missing link, you need to visualize evolution as a chain. If there’s a gap in the chain, then you have a missing link. The fact is that all fossil species represent a transitional form. Like all living species, they possess a combination of unique traits and features inherited from distant ancestors.
Second, the phrase leads to misconceptions that our human origins are basically linear and straightforward. Human origins are a far messier affair. Evolution, at least at the scale of animals and plants, is mostly a “tree” with branches, twigs, leaves, etc. There were many dead-ends and blind alleys with perhaps dozens or even hundreds of our ancestral cousins becoming extinct. The existence of an evolutionary family tree is no longer questioned today, but rather the questions revolve around its size and shape – essentially “who is related to whom.”
Thus the chain metaphor is wrong. It doesn’t accurately represent biology as we know it today, but as it was understood over four centuries ago. The myth persists because of convenience; it is easier to think of species as types, with discrete qualities, than as grades between one species and another. In school, we learn the specific characteristics of plants and animals; this alone is not a problem, except that we are not often exposed to the main ramification of evolution: that those characteristics will change through time…and change is the essence of evolution.
So, our idea that there can even be such a thing as a “missing link” was created in an era of biological research which is long gone. It’s a concept which is no longer valid in our current understanding of the nature of life and evolution — As Darwin himself said, in The Descent of Man, “In a series of form graduating insensibly from some apelike creature to man as he now exists, it would be impossible to fix any definite point where the term “man” ought to be used”. 
I really hope that I have contributed in helping put this myth to rest. Below are some very distinguished and credible resources to aid you, should you want to inquire more about this subject.
Thanks for reading,
- Potts, Richard; Sloan, Christopher, “What Does It Mean To Be Human?”, National Geographic Society, 2010, Smithsonian Institution, ISBN: 978-1-4262-0606-1
- Dawkins, Richard, “The Greatest Show on Earth: The Evidence for Evolution”, Free Press; First Edition, September 22, 2009, ISBN-10: 1416594787