Not one of my favorites, for a few reasons. Stu seemed to be the closest thing to a fully realized character in the story, and even he kept fading into a single-dimensioned megalomania as the story moved on. A few problems.
First, the initial set-up. From the instant we saw the femur everybody reading it knew it would be Stu's. The bones always belong to the person who found them in the present.
Second, more damningly, the debate between the scientists. It annoys me when a scientist in a story argues against creationism with a simple, "No, that's not true. It violates the laws of evolution". This is the kind of thinking creationists use, starting with the conclusion and massaging the evidence to fit. A better retort to the young scientist would be that using Creation as an explanation ignores mountains of evidence to the contrary which is still yet to be refuted. A time traveller actually fits the evidence better because that explanation would more likely account for only one human femur being found from that period. Ever. That it was just something that looked like a human femur but really wasn't is an even better possiblity that nobody seemed to consider. As written, the story has no character who embraces the scientific method and looks at it as a scientist would.
If time travel is available when Stu's wife is from, wouldn't someone already have gone back to check out the dinosaurs? She could have learned in grade school that Brontosauruses are pink with green spots.
I liked that Stu only got back to the past posthumously, but on reflection the gesture seemed a bit empty and sentimental. If his son actually does invent a time machine, what's to stop him from going back a few years before his Dad died and letting him play with it?
All in all, I felt that it was a little bit sentimental and a little bit sloppy in the plotting to be truly engaging. On the positive side, I do love the title.