The missing link is alive but not so well - the story of an intrepid explorer - an unclassified museum specimen – and the most controversial book ever written.

Hey William!

You need to get rid of the dashes for starters.

A common mistake in loglines is telling too much or not telling enough.

The latter applies to you here. It comes across as too factual, but at the same time not enough info, and too abstract. You need to inject life into it, tease us with your story.

You need to describe the -

          the protagonist
–       their goal
–       the antagonist/antagonistic force.
Your hero's goal, the stakes, and the urgency/consequences.

Here's Indiana Jones:

In 1936, archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before Adolf Hitler's Nazis can obtain its awesome powers.

Pretty exciting, right?

So, questions for you to help further construct your Logline:
Who is this guy? Why should we care?
What is the missing link, what's the book? Is the specimen one and the same thing?

Okay, your hero is 'intrepid' not the strongest adjective.
What are the stakes, what's he stand to lose, his life? What if he fails?  
Who is the antagonist?

In this case yep, a short synopsis might help.

Hello.
I posted this a week ago and received no comment.
I genuinely wonder is it that far off the mark that it doesnt warrant any comment?
Did I need to preface it with a synopsis perhaps ?

"The missing link is alive but not so well - the story of an intrepid explorer - an unclassified museum specimen – and the most controversial book ever written."

Quoted from LC Hey William! You need to get rid of the dashes for starters. A common mistake in loglines is telling too much or not telling enough. The latter applies to you here. It comes across as too factual, but at the same time not enough info, and too abstract. You need to inject life into it, tease us with your story. You need to describe the -           the protagonist –       their goal –       the antagonist/antagonistic force. Your hero's goal, the stakes, and the urgency/consequences. Here's Indiana Jones: In 1936, archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before Adolf Hitler's Nazis can obtain its awesome powers. Pretty exciting, right? So, questions for you to help further construct your Logline: Who is this guy? Why should we care? What is the missing link, what's the book? Is the specimen one and the same thing? Okay, your hero is 'intrepid' not the strongest adjective. What are the stakes, what's he stand to lose, his life? What if he fails?   Who is the antagonist? In this case yep, a short synopsis might help.

Wow, excellent, thanks for that depth of feed back there LC. Very pleasing and much appreciated. I was, coincidentally mindful of Raiders of the Lost ark when I fleshed out the many action scenes in  "The fifth ape" except mine are more exciting .. huge claim I understand.
Back to the drawing board.
Thanks again.