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Re: Paired Eggs in a Dinosaur Indicate Biological Sex
That means *three* species of nonavian dinosaurs are known to have had
Troodon, Citipati, and the undescribed oviraptorosaur.
Varricchio et al 1997. Nature 385. Jan. 16. pp. 247-250.
Norell et al. 1995. Nature 378. Dec.21/28. pp.774-776.
Sato T. et al. 2005. Science 308:375-376.
On Thu, 14 Apr 2005 13:50:37 -0700 (PDT) "Jaime A. Headden"
> ... and support Norell's contention in 1993 that *Citipati* had
> paired oviducts
> used in series to lay rings of eggs.
> Sato T., Cheng Y.-N., Wu X.-C., D. K. Zelenitsky, and Hsiao Y.-F.
> 2005. A Pair
> of Shelled Eggs Inside A Female Dinosaur. _Science_
> 308:375-376. (w/ supp
> "An oviraptosaurian specimen (Dinosauria, Theropoda) from an Upper
> formation in China retains a pair of shelled eggs in the pelvis,
> direct evidence that oviraptorosaurian dinosaurs laid paired
> eggs. The presence of the paired eggs suggests that theropod
> dinosaurs had
> two functional oviducts (like crocodiles) but that each oviduct
> one egg at a time and that an entire egg clutch was laid through
> ovipositions (like birds). The orientations of the eggs inside
> the skeleton
> and in clutches indicate that the mother came to the center of
> the nest to
> lay eggs."
> The specimen is very incomplete, comprising the lower pelvic
> canal, but it's
> indications for oviposition are clear both from fossil nests and the
> pairing of
> eggs in those nest and in this specimen. The relatively intact
> though crushed
> eggs within the pelvic canal indicate without much room for doubt
> the sex of
> the dinosaur, for the first time.
> Jaime A. Headden
> Little steps are often the hardest to take. We are too used to
> making leaps in the face of adversity, that a simple skip is so hard
> to do. We should all learn to walk soft, walk small, see the world
> around us rather than zoom by it.
> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
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