dinodimorphism

[Nick Longrich <longrich@alumni.princeton.edu>]

>  >The robust morphotypes are usually considered the females in fossil
> theropods, and the gracile ones the males. i.e., natal males would not mate
but immigrant males would.<
> As HP Headden wrote, there is no real way to determine sex in theropods that
> really holds up to scrutiny (at least that I know of). While the
> determination of the presence or absence of sexual dimorphism can be gleamed
> from some groups of dinosaurs, I think that trying to determine the sex of a
> fossil dinosaur is probably a pipe dream. If someone proves me wrong,
> however, I'd be very excited. ;)
> Peace,
> Rob

	There's a way- eggs found inside a gracile or robust 
morphotype would pretty clearly demonstrate that one of the morphs 
was female. There may be other ways, if similar dimorphic patterns in 
the skeleton can be shown to exist in either crocs, birds, or 
preferably, both. My personal suspicion is that the males were the 
larger and more heavily built ones, since this better fits the 
pattern in modern terrestrial carnivores, but this of course remains 
to be tested. I think sooner or later we're going to figure it out- 
we found out what theropod integument looks like after all, and I 
don't know that many of us thought we'd live to see that.

        Nick