Re: Cope's Rule in the Pterosauria - Hone & Benton 2007

[Michael Habib <mhabib5@jhmi.edu>]

> Yes, this is what I was driving at.  The idea that pterosaurs were 
> mostly coastal fish-eaters has become as entrenched as the idea that 
> Mesozoic birds were predominantly insect-eaters.  Yet, many Mesozoic 
> avians show adaptations and/or abdominal contents consistent with 
> fish-eating, or at least an aquatic/marine habit.

True.  Furthermore, I am personally a bit perplexed how pervasive the 
"competitive exclusion by other flying vertebrates" concept is.  It's 
not a bad concept, per se, but it is a little vague.  We do not tend to 
take the same attitude with any other locomotor type.  We do not, for 
example, tend to jump at a competitive exclusion hypothesis for two 
fossil clades if their primary similarity was simply being terrestrial 
or aquatic.  Flight is not somehow special in 'allowing' a smaller 
number of species.  In fact, the opposite is closer to modern reality: 
insects, birds, and bats are all very large clades (by standards of 
both abundance and species diversity).

> Also, members of the pterosaur family Anurognathidae (_Anurognathus_, 
> _Batrachognathus_, _Dendrorhynchoides_, _Jeholopterus_) had a 
> morphology consistent with catching insects 'on the wing' - big eyes, 
> wide mouths, and perhaps wings and tail adapted for slow, maneuverable 
> flight.

Most definitely.  And, it turns out that there are certain structural 
features of the forelimbs that are common amongst avian aerial hawkers 
that I suspect will be diagnostic for that ecomorph in pterosaurs as 
well (as they are related to the mechanics of that particular flight 
regime).

Cheers,

--Mike H.