Platyhystrix and dino sails

["Stephen Priestley" <sn2192@uniserve.com>]

meor hakif wrote:
> ive been doing some reading about animal behaviour, and found out that in

> sexual selection, females tend to prefer males with the boldest 
> characteristics (bigger size, brighter colors, larger sails?) . So, if 
> Dimetrodon's sail was used in sexual display, wouldn't repeated selection
of 
> males with larger sails  lead to an exageration of that trait? And could 
> this pattern of larger sails be seen in the fossil record(possibly by 
> comparing fossil specimens of the same species from rock of different 
> ages?)..well. its just an idea.:) meor hakif

Trouble is, with most of the "fin-backed" pelycosaurs there's no fossil
record of finless "females". Even if you went out on a limb and said that
_Sphenacodon_ was really a female _Dimetrodon_, you'd be hard pressed to
find an _Edaphosaurus_ without the fin.

Does anyone know if there are any remains which suggest a finless
_Ouranosaurus_ or _Spinosaurus_?

Stephen Priestley