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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
lived, 
>  according to his calculations, lies somewhere between 645 and 3285, with 
>  a most probable value between 900 and 1200.
<SNIP>

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
dinosaurs 
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. 

Mary
mkirkaldy@aol.com