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