I believe this site may have been referenced here once before, but here it is again.
This is possibly the most thorough exploration of a what-might-have-been alternative earth, at least from the biological perspective. A team effort which will take readers days to explore and is still unfinished.
http://www.geocities.com/dbensen2/index.html
Here is a more direct link into the good stuff:
http://www.bowdoin.edu/~dbensen/Spec/Beasts.htm
This is possibly the most thorough exploration of a what-might-have-been alternative earth, at least from the biological perspective. A team effort which will take readers days to explore and is still unfinished.
http://www.geocities.com/dbensen2/index.html
Here is a more direct link into the good stuff:
http://www.bowdoin.edu/~dbensen/Spec/Beasts.htm