RE: Russian Dinosaurs in T.O.: Longisquama

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

Silvio Renesto wrote:

> IMHO display either for mating or for threatening of potential 
> predators is probably the best interpretation for the elongate 
> appendages of Longisquama. 

Methinks the feather-like appendages might have been used to tickle the
noses of potential predators.  As the watery-eyed predator hauled back for a
sneeze, the _Longisquama_ made its getaway.

> On the other hand parachuting might be feasible. 

On a serious note, this (and/or an ornamental mating structure) is the most
plausible interpretation for _Longisquama_'s appendages.  IMHO.

>   Haubold and Buffetaut (1987) proposed that Longisquama was able to 
> spread out the plume-like appendages at its sides forming a sort of
> gliding "wing" like in kueheneosaurid/coelurosauravid/ Draco. This 
> gliding apparatus would perhaps  have been uneffective, I suspect, 
> owing to the lack of a continuous  surface. Thus I prefer to stick to 
> the display.

Haubold and Buffetaut (1987) did not sufficiently demonstrate that these
appendages were paired, nor mobile.  Under their interpretation, the
plume-like appendages could be used for gliding, then folded above the back
like the wings of a butterfly when not in use.  This interpretation has been
siezed by those who would like to connect _Longisquama_ (in whatever
capacity) to the origin of birds.



Tim

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

Timothy J. Williams 

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

Phone: 515 294 9233 
Fax:   515 294 3163