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Re: Re : undiscovered dinosaurs

In a message dated 5/22/98 9:02:15 PM Eastern Daylight Time,
Dinogeorge@aol.com writes:

>  HOW MANY dinosaurs were there? This question was recently addressed by 
>  Dodson (1990a), who applied statistical methods and a few seemingly 
>  reasonable  assumptions about collection and preservation biases to the 
>  dinosaur fossil record. The total number of dinosaur genera that ever
>  according to his calculations, lies somewhere between 645 and 3285, with 
>  a most probable value between 900 and 1200.

Dale Russell, in the Ask the Expert column last year on MSN Schoolhouse, 
gave the following answer to the question "How many different kinds of
were there?" 

>  It is difficult to know the total number of different kinds of dinosaurs 
>  that lived at one time or another during the dinosaurian era. Two friends 
>  of mine are both dinosaur experts and their estimates differ a lot. Dr. 
>  Peter Dodson, on the basis of a few great fossil fields, suggested that 
>  there were altogether about 1,200 kinds (genera) of dinosaurs; his 
>  colleague George Olshevsky, on the basis of the number of different
>  kinds of mammals and birds living on Earth now, felt that 11,400 was 
>  a closer estimate. From the number of mammals living about a million 
>  years ago on continents of various sizes, I suggested that perhaps 
>  3,400 different kinds of dinosaurs once lived on Earth. 

>  The truth may lie somewhere within this range. But depending on 
>  which estimate you choose, 76 percent to 92 percent to nearly 98 
>  percent of all the dinosaurs that ever lived have not yet been discovered. 
>  There is a lot of work for young dinosaur specialists to do.