Bryson, Bill - On the number of configurations
Type of Spiritual Experience
It is impossible to deduce just how many configurations there have been from the fossil records. The fossil record is biased towards sea creatures [because land based creatures are often eaten or weather down to nothing] and creatures with bones. Even then only about 1 bone in every billion is believed to become fossilised. Finally, the majority of the earth's surface has not been explored for fossil remains. Most of what has lived on earth has left behind no record at all. As such we know very very little of what has lived on earth.
If there were more species ,then there were simply more configurations, the number of which will probably never be known. The greater the number of species, however, the stronger becomes the argument for objectives based on maximising functionality.
A description of the experience
Bill Bryson - A Short History of Nearly Everything
No one knows how many species of organisms have existed since life began. Thirty billion is a commonly cited figure, but the number has been put as high as 4,000 billion … Whatever the actual total, 99.9% of all species that have ever lived are no longer with us …. For complex organisms, the average lifespan of a species is only about 4 million years......
… bearing in mind fossils can be buried anywhere within an area of slightly over 9.3 million square kilometres, little of which will ever be turned over, much less examined, most fossils will never be known