RE: A New Hypothesis for the Origin of Flight?

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Jaime Headden wrote:

> "Pointy" skulls are not neccessarily insectivoran; birds that are
> adapted insectivores tend to have broader jaws, as do most animals that
> feast upon these protein-sinks. This is evident in many anurans; birds
> like *Aegotheles* (owlet-nightjar), nighthawks and frogmouths, swifts,
> etc. 

And in the wide-mouthed anurognathid ("frog-jawed") pterosaurs as well -
probably for the same reason: catching insects out of the air with the jaws

I've seen this argument previously in the literature: that coelurosaur jaws
were narrow and therefore poorly designed for snatching flying insects out
of the air.  I think it's a cogent argument against birds evolving from
theropods that leaped (or swooped) into the air against flying insects.
Further, catching aerial insects on the wing (as caprimulgiforms and
apodiforms do today) requires different adaptations to ground-level
insectivory (as employed by the majority of insect-eating mammals outside of
the Chiroptera).  

Jaime also wrote:

> They are corpses ... corpses do nothing on their own.

And even when skeletons are preserved _in situ_, there are differing
interpretations.  For example, the famous "Fighting Dinosaurs" - a
_Velociraptor_ and _Protoceratops_ locked together - there are differing
views on how the skeletons precisely came to be in that pose.



Tim


------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163