Dr. Peter Wellnhofer, in his book The Illustrated Encyclopedia of Pterosaurs (Salamander Books, 1991) on page eleven mentions that fossilization is an exception to the general rule about what happens to organisms after death; he also mentions that this rarity of fossilization is particularly relevant to pterosaurs, for their bodies were light and fragile. I believe that this concept is generally accepted among paleontologists.
In my post of July 17, 2010, I mentioned a blog post (on Science Blogs) by the paleontologist Darren Naish, who has a special interest in pterosaurs. He said, “The fossil record convincingly demonstrates that pterosaurs became extinct . . . [by] 65 million years ago.” But he gives no line of reasoning for that declaration. In The Illustrated Encyclopedia of Pterosaurs, Wellnhofer makes it clear that pterosaur extinction was not an event but a long process. I believe that Naish needs to make a choice here: Accept Wellnhofer’s proposition about gradual extinction of pterosaurs or give some line of reasoning for a quick extinction of many species of pterosaurs.
I suggest we all try to use clear thinking about this idea of universal extinction, this assumption that all species of pterosaurs became extinct. Somewhere, somebody (I believe it was Naish or Glen Kuban, or someone commenting on one of their blog posts) said, “If a group of organisms are absent from the fossil record for tens of millions of years, and if there is no evidence indicating their survival across or beyond that time, they should be assumed to be extinct.” That reasoning is faulty, for too many obvious exceptions shoot it down.
Kuban has admitted the possibility of extant pterosaurs but greatly doubts it. Both Naish and Kuban have fought vigorously to extinguish any hope for living pterosaurs in modern times. But where is the reasoning for universal extinction of all species of pterosaurs?
Both Naish and Kuban seem to have been oblivious to the obvious conclusion that Wellnhofer unwittingly allowed. If only a tiny portion of pterosaur remains have been discovered as fossils, how many species may have existed of which we are unaware! Since we have no fossil evidence for the life of many species of pterosaurs, how can we come to any conclusion about any extinction of even one of those undiscovered species? Protecting the reputation of standard paleontology should not be the primary objective of paleontologists: The first priority should be to know the truth.
For a few brief statements about pterosaur extinction (or lack thereof), see Questions and Answers.