re: Tanystropheus egg question.

[david peters <davidrpeters@earthlink.net>]

Here's a rough hypothesis, in lieu of hard data either way.

If the epipubic bones turn out to be oversized hemal arches, with anterior 
articular surfaces instead of sharp points, then that clears the way for the 
posterior shifting of the cloaca -- incrementally making room for an ever 
longer stiffer cervical series in the neonate. Development in utero would not 
hinder development of a stiff neck, as it would within the typical confines of 
spheroid.

So rather than indicating male gender, these unusual paired bones may signify 
the female gender. 

Falsifiers, if ever found:
1. eggs.
2. epipubic bones of the same sort on short-necked genera.
3. sharp points on the epipubic bones (I know, they're on Wild's and Olsen's 
illustrations, but are they really there? On verifiable specimens, one each of 
Tanytrachelos and Tanystropheus, they are not sharp).
4. Two tanystropheids fossilized while makin' bacon and the one on top has 
epipubic bones.

David Peters
St. Louis