Where Are the Very Old Native Bones?

As stated in Charles Mann's novel 1941:

Paleo-Indian skeletons are extremely rare. In Europe, archaeologists have discovered scores of skeletons ten thousands years old or more. By contrast, only nine resonably complete skeletons of similar age have been found in North America (a few more exist in South America, although, as with the Lagoa Santa skeletons, their provenance is often unclear). "It's a big mystery why we don't find the burials," the University of Vermont archaeologist James Petersen told me. *

It is a very good question.

Where are the thousands of years old skeletons of South and North American native inhabitants? It depends on may things I suppose. (And what actually is the count for aged European skeletons vs. aged American skeletons?)

Method of 'burial' for one -- in the ground, beneath cairns, air burial, cremation and I'm sure there's more with intricate steps that I'm not familiar with.

Conditions that preserve skeletons for another -- in which type of soils do bones disintegrate? How long does bone disintegration take in those types of soil? What methods of preserving bodies are practiced (not just mummification but use of sarcophagi, removing the flesh, etc.)? Under which conditions are bones best preserved? How many of the European and American burials are accident vs. deliberate interments? Are the European numbers high because burials simply occurred in the right conditions for preservation?

As they say in retail, location, location, location -- European culture tends to be a socially stratified one, thus individuals of high status are buried in significant marked grave sites. Those grave sites are readily discovered with a wealth of burial goods, but were are the skeletons and grave goods of those that buried those kings and priests? In either European or American lands? Also when one considers the population density on available land on either continent, a great deal of American land is cultivated farm land with no previous archaeological examination. Who knows what's buried underneath a farmer's field deeper than the plough? Are they looking in the right place? Do they know were the 'right' place to look is?

How graves are marked -- has the landscape been significantly altered or marked in some manner that indicates a burial site or burial ground? Is the site marked with earthen mounds, below ground or above ground tombs, gravestones, or other distinctive 'grave' architecture? Is there a unique communal site used for interment like a cave where multiple skeletons would "accumulate" over time? Or are graves located next to a significant location be it spiritual (e.g. underneath a church) or secular (e.g. outskirts of a settlement)?

Oy. I think that's enough for now until I get some answers to a few of the questions I've just poised. Though now I wonder where I could find the answer to some of my questions. I also wonder if there are any (and where they are) archeological or forensic papers written about some of the issues...

Any help? Or your thoughts about this post?

Citation:
* Mann, Charles C. 1491: new revelations of the Americas before Columbus. New York: Vintage Books, 2006. p. 169.