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Re: Paired Eggs in a Dinosaur Indicate Biological Sex

At 6:19 PM -0700 4/14/05, Jaime A. Headden wrote:
><Let's not forget the paired eggs found within _Sinosauropteryx_.>
>  I think the "eggs" found therein are two small and too far forward to
>effectively determine this. The shapes and sizes are alarminly small compared
>to the sizes seen in other eggs compared to their respective layers. Similarly
>sized maniraptorans like the aforementioned troodontids and oviraptorids have
>eggs relatively MUCH larger compared to the masses found in *Sinosauropteryx*,
>so this would likely need to await corroboration. The position of the masses,
>if eggs, may be indicative of an intestinal position as well as any oviduct
>position. Similarly, development of a shell occurs further towards the cloaca
>than where the ovaries are likely to be indicated, and these masses were found
>near to where you'd expect the ovaries or kidneys to be placed, directly
>anterior to the puboiliac contact.

At least one of the paleontologists I talked with recently was not convinced 
those were eggs in Sinosauropteryx. (Sorry, but I can't remember who because I 
was working on a big project and talked to a lot of people.) It was not that he 
could prove they weren't eggs, but that there wasn't enough evidence to prove 
that there WERE eggs. They do not preserve shell. The new fossil does preserve 
shell, with features which match known fossil eggs, so there's no doubt what 
they were and good evidence they were about ready to be laid. 

Jeff Hecht, science & technology writer
jeff@jeffhecht.com; http://www.jeffhecht.com
Boston Correspondent: New Scientist magazine
Contributing Editor: Laser Focus World
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