Re: Possible Tyrannosaurid nesting behaviour

[Dino Guy and Computer Gal <gbabcock@best.com>]

The large eggs from the lower Cretaceous of China which Ken Carpenter displays
in "T-rex: The Ultimate Guide" are not identified as belonging to
_Tyrannosaurus_ (which never lived in Asia).  These large elongate eggs --
_Macroelongatoolithus xixiaensis_ -- are featured extensively in the May 1996
issue of _National Geographic_.  In fact, the "Baby Louie" embryo (given this
nickname after the photographer, Louie Psihoyos), also seen in the program, is
on view in Philip Currie's "The Great Dinosaur Egg Hunt" article in this issue
in fossil form and was the basis for Brian Cooley's model on the cover.  It is
tentatively described as a therizinosaur, based on the fossil embryo, although
the egg differs markedly from Terry Manning's therizinosaur eggs (as seen in the
pages immediately following the _Macroelongatoolithus_ coverage, again with a
photograph of the embryo fossil and a Brian Cooley model).
_Macroelongatoolithus_ eggs are also featured in the photograph on pp. 98-99,
comprising a two meter wide radial clutch of at least 26 eggs arranged around an
empty center.

In "T-rex: The Ultimate Guide," Carpenter was using the eggs to demonstrate the
general nature and scale of large theropod eggs and hatchlings.  I am not aware
of any eggs identified as tyrannosaurid, though I'd be happy to hear of any.
Relatively few oospecies (egg species) have been positively matched to
particular dinosaur taxa.  This requires a direct association between eggshell
and embryo material.

If you don't have the magazine, see
<www.nationalgeographic.com/dinorama/eggs.html>.  In fact, you should check it
out whether you have the magazine or not.  It contains images and text that are
not in the original article.  If you want to explore this topic further, I
strongly recommend Ken Carpenter's _Eggs, Nests, and Dinosaur Babies_, a
thorough, occasionally humorous, accessible, and well illustrated effort, and
less expensive than some of the other essential dinosaur texts to come out in
recent times.

--
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Ralph W. Miller III   ralph.miller@alumni.usc.edu

And, of course, contrary to the video title, it should read _T. rex_