Re: dinosaurs'sex life

[Stanley Friesen <sarima@ix.netcom.com>]

At 08:42 AM 11/12/98 +0100, Patrick Chevallier wrote:
>>>> 
I don't know much about dinosaurs, but I realize we never read anything
about the dinosaur's sexuality. I suppose evidence is hard to find, but
does anyone have any information about this question ?
<<<

Well, it is hard to come up with much detail, given all we have are bones,
eggs, and a small handful of skin impressions.

In general, theropod sexuality is apt to be more or less similar to that of
living birds.  The main difference is that non-avian theropods tended to
lay more eggs than just about any modern bird.

There are many features of dinosaurs that appear to many to be display
structures.  Since such structures tend to be related to sexuality, or at
least mate selection, in living animals, it is likely the same in dinosaurs.

The horns and frills of ceratopsian, the thick skulls of pachycephalosaurs,
and, *I* believe, the plates of _Stegoaurus_ are most similar to structures
used today to establish dominance hierarchies and/or mating territories.
Even when not directly involved in mate selection, such hierarchies and
territories are critical to mating success.

Then there are the crests of many hadrosaurs, and the crests, ridges, and
hornlets of many theropods.  Based on modern analogies, these are likely to
have been used more o less directly in attracting mates.  Since all living
archosaurs have color vision, and male birds are often brightly colored to
attract mates, I am rather certain that these structures were quite bright
indeed, at least in the mating season.

--------------
May the peace of God be with you.         sarima@ix.netcom.com
                                          sfriesen@netlock.com