Re: Dinosaur counts

[Stan Friesen <swf@ElSegundoCA.ATTGIS.COM>]

 From: paleo@ix.netcom.com (Glen J. Kuban )
 >      Anyway, since I monitor the C/E controversy and may write on this 
 > someday, I thought I would ask here: What does the 775 general count 
 > recently posted represent?  Is that the number of genera ever 
 > named/published?

Pretty much, yes.

 > What is the best estimate of the number of valid 
 > names (eliminating synonyms, dubia, etc)?  An even tougher question  
 > might be: about how many different or valid *species* are known?    

My synonymized list has only about 400 genera, and most of those
are nomina dubia (poorly preserved forms of doubtful value). I
suspect there are between 100 and 150 valid genera of dinosaurs
now *known*, and around 200 valid species.
  
 > Another, perhaps even more speculative question might be: how many 
 > dinosaur genera/species are likely to have lived in the entire 
 > mesozoic?  ... 

However, those numbers are only based on currently *known* forms.
Given the rate of new discovery, and the sparsity of the fossil record,
the actual number of dinosaur species that lived may well be around
ten times this number.

 > This will lead of course automatically provide estimates of
 > the percentage of dinosaurs that have already been found and the 
 > percentage remaining to be found.  

Actually, one does this the other way around - first estimate the
percentage representation and then use that to estimate the original
number of species.

 > Besides helping me with my little  
 > project above, I suspect there are some teachers in the audience who 
 > often get questions like this from students, and might be interested in 
 > the responses.  
 > 
 > Thanks,
 > 
 > Glen J. Kuban
 > paleo@ix.netcom.com
 > 
 > 

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.