The spores in question were 20 to 40 million years old. If one considers
however, the age of the planet (4,500 Myr) and the length of time that
microorganisms have been in existence (~3,500 Myr), then 20 to 40 Myr
is not so long. Now B. sphaericus and its buddies are also around a long time
as a matter of fact 40 Myr is not a long time in evolutionary terms. So,
40 Myr ago there were bugs in existence that were very similar to B. sphaericus
(maybe there were bugs that were indistinguishable from the B. sphaericus
This is one of the most fascinating things about evolution....the time scale.