Re: Pterosaur size (Was: Great in the air, not so good underwater)

[Jamie Stearns <stearns5@cox.net>]

To me at least, dinosaur body size, for saurischians at least, seems to 
reach its peak around the Cenomanian/Turonian, with theropods like 
Spinosaurus, Mapusaurus, and Giganotosaurus and sauropods like 
Argentinosaurus and Paralititan. Body size seems to decline in sauropods 
afterward, Bruhathkayosaurus, if a sauropod at all, being an exception. The 
carnosaurs and spinosaurs appear to go completely extinct at that point for 
some unknown reason.

What is interesting here is that most of these truly huge sauropods and 
theropods are from Gondwanaland, suggesting that geographic isolation may 
have been involved.

Then again, there are lineages that actually decrease in size over the 
Cretaceous, not just titanosaurs, but dromaeosaurs are another example; 
compare Utahraptor and Deinonychus from the EK to Bambiraptor and 
Saurornitholestes from the LK. Though I  can't recall exactly when 
Achillobator lived; that might throw the pattern off.