From all my reading on primitive archery (the whole 5-book Primitive Bowyer's Bible series, for one) it's obvious that our ancient ancestors used all manner of points and likely tried nearly anything they could think of.
The South American Indians, moth Maya and Aztek, used this construction for various of their striking weapons, and we know that there was some trade between these cultures and Native Americans.
Likely some inventive tribesman saw similar weapons and thought he'd give it a try?

i saw something like it from ray mears before. he had an arrow with a flint tip, and another flint piece behind the tip on the shaft so that it looked looked like a fin coming off it and would widen the blade. the thing went into a leg of lamb, possibly frozen and stuck 6 inches down maybe. don't remember the exact video.

  I think that was mainly used as a way to use your smaller flakes that you wouldn't make into arrowheads.  You could take a bone, ivory or wood barbed harpoon point and give it a cutting edge like that of a stone point by inserting some of your waste flakes, ( or specially struck blades from a blade core,)  I know they inuit often used ground slate blades on their bone, antler or wood harpoon points so that they would cause more blood loss.
  I would think that they wouldn't last as long as a knapped or ground stone point as a flake like that has a fragile edge seeing as it is so thin and narrow and would likely get broken up going through bone.
 
  For another example of this type of thing google Macuahuitl, it is an Aztec sword made with blade inserts.

microblade technology, as it's called, goes waaaay back! much farther than the mesolithic, to the Paleolithic and possibly beyond. almost all the spear points found in western and central asia are composites of antler and microliths and were probably employed by the first settlers of the Americas. there is even evidence that Neanderthal used this technology. when you think about it, it just makes sense. an antler point is both easier to make and more robust than an all stone point, and with the addition of microblades it becomes a more efficient one as well. it is also more economical. with the right technique, you can strike off hundreds of microliths from just one modest stone core whereas you might only get two or three full stone points. this becomes especially important in areas where knappable stone is rare, like the Artic regions. the Meso American cultures, like the Aztec and Maya, employed it for both points and striking weapons because of the extreme sharpness of the untouched edges of microblades, and because they are easily replaced when broken. the Natufian cultures (predecessors of the earliest farmers) made microlith sickles to harvest wild grain and tipped their hunting points with them as well.

paleoarts, thanks for the pics I think I see a bit better how it could be used for a piercing weapon. I see that you've "sloped" the first micro blade so it easily widens the cut started by the antler puncturing the skin. That was one of my main questions as it seemed to me that the microblades should snap off rather than widen the cut. I knew that they were used for a striking weapon by the aztecs, but I couldn't see how it would work for piercing. Thanks!

Have you used any of your composite points on targets to get an idea of how well they function?

My camera is still refusing to shoot pictures! 

By the way, while writing my thesis I found a very interesting book, written by 2 Italian experimental archaeologists that have experimented some Bronze Age bows found in Northern Italy (a site called Fiavé Carrera).

Of course they made and shoot some composite points; it seems that this kind of point was still used in Northern Italy well after the Neolithic and Copper Age, toghether with more modern flint arrowheads.

This's the book:

AUTHORS: P. Bellintani and F. Cavulli.
TITLE: "Catene operative dell'arco preistorico - incontro di archeologia sperimentale" ("Building and using a prehistorical bow - experimental archaeology meeting").
PUBLISHED IN: Trento
YEAR: 2006.

There's not the Editor because they printed it at the university of Trento.
I really hope you may find it; otherwise I may go to the Archaeological Superintendence and scan some pages!
Let me know!
Mauro.

I knew I had this pic!
Here's what they found somewhere in Italy (can't remember where!):



The caption says:"Bone harpoon with geometrical microliths".
It's a Late Mesolithic (Epigravettian) tool 
Greetings,
Mauro.