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Re: Where are the egg shells



Plenty of modern birds simply carry the shell fragments away from the nest 
after hatching, to 
prevent their smell from attracting predators to the nest. If small ornithopods 
nested in burrows, 
then the smell of newly-hatched egg shells could well have attracted unwanted 
attention from 
predators such as large pythons or badger-sized mammals. Eating them could also 
have been a 
valid method of disposal, although disposing of them elsewhere might actively 
lead scent-dominant 
predators away from the burrow.

Similar structures to the North American burrows have been identified in 
Southeastern Australia, an 
area where dinosaur fossils tend to be dominated by small ornithopod remains.

On Wed, Jul 10th, 2013 at 6:27 AM, john-schneiderman@cox.net wrote:

> Bakker (1990) described tightly-packed pods of 6 to 35 individuals which 
> he interpreted as representing groups of Drinker in burrows, perhaps 
> drowned by flooding or killed by disease. If Drinker was indeed a 
> burrower, it would be among the first known for dinosaurs; the only 
> well-supported published case of a fossorial nonavian dinosaur is the 
> more recently discovered, distantly related Oryctodromeus. One problem 
> with Bakker's interpretation was the lack of fossilized egg shell 
> fragments amongst the individuals which he stated (1992) was a family 
> group of many juvenile/hatchlings with adults within a nesting burrow 
> found in Como Bluff, Wyoming.
> 
> Supporting the nesting burrow idea, is it possible that a behavior 
> amongst Drinker, and possibly other small ornithopods, were for the 
> adults to consume the egg shell fragments after the the babies hatched 
> as a means to replenish their loss of calicum, and thus no egg shell 
> fragments to be found in the nest? Egg and egg shell eating is common 
> amongst the birds ("Dinosaurs") today.
> 
> References:
> 
> -- Bakker, R.T., Galton, P.M., Siegwarth, J., and Filla, J. (1990). A 
> new latest Jurassic vertebrate fauna, from the highest levels of the 
> Morrison Formation at Como Bluff, Wyoming. Part IV. The dinosaurs: A new 
> Othnielia-like hypsilophodontoid. Hunteria 2(6): 8-14.
> -- Bakker, R.T. (1990). A new latest Jurassic vertebrate fauna, from the 
> highest levels of the Morrison Formation at Como Bluff, Wyoming, with 
> comments on Morrison biochronology. Part I. Biochronology. Hunteria 
> 2(6):1-3.
> -- Bakker, R. T. (1997). "Dinosaur mid-life crisis: the 
> Jurassic-Cretaceous transition in Wyoming and Colorado". In Lucas, S.G., 
> Kirkland, J.I., and Estep, J.W. (eds.). Lower and Middle Cretaceous 
> Terrestrial Ecosystems. New Mexico Museum of Natural History and Science 
> Bulletin 14. New Mexico Museum of Natural History and Science. pp. 
> 67â??77.
> -- Varricchio, David J.; Martin, Anthony J.; and Katsura, Yoshihiro 
> (2007). "First trace and body fossil evidence of a burrowing, denning 
> dinosaur". Proceedings of the Royal Society B: Biological Sciences 274 
> (1616): 1361â??1368.
> -- Dinosaur Parents, Dinosaur Young: Uncovering the Mystery of Dinosaur 
> Families By Kathleen Weidner Zoehfeld;  HMH Books for Young Readers 
> (January 22, 2007) ISBN-10: 0618752447 pgs: 31-32.


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Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
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