There have been excavations over the last 100 years by different explorations on Easter Island to examine these heads and earlier ion the 20th century they found the herads did have bodies.  A more recent series of expeditions since 1982 has uncovered some of them to a depth of 7m or so to show petroglyphs of symbols on the backs of the torsos.







News here:  http://news.yahoo.com/blogs/sideshow/easter-island-statues-full-bodies-contain-ancient-petroglyphs-235631403.html

and here..  http://www.livescience.com/20580-easter-island-heads-bodies.html

Research group here...  http://www.eisp.org/

Also earlier details here...

http://www.eisp.org/category/archaeology/expeditions/routledge/
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