Re: fossialization and floods

[rjmeyer@ix.netcom.com (Rob Meyerson)]

>        I was watching an old videotaped NOVA (about T-rex) recently when a 
>thought occurred to me.  For an animal as big as a dinosaur to become 
>a fossil, it has to be buried fast enough that scavangers can't get 
>to it.  Am I correct in thinking that these conditions usually 
>only occur in floods?
>        I realize that there are some exceptions to the rule (such as the 
>Gobi dinos that buried by collapsing sand banks), but my point is 
>that a majority of fossils of large animals are created by floods.  
>Am I right or wrong?

I don't think this is accurate.  A couple of summers ago, I had the opportunity 
to help excavate a fairly complete _Camarasaurus_ skeleton.  A few facts helped 
to support the idea of a gradual, gentle burial.  Firstly, the animal was lying 
on it's back; a storm would most likely leave the animal on it's side.  The on 
site interpretation is that as the animal decayed, the weight shifted, bringing 
the animal onto it's back.  Secondly, the matrix had no sedimentary features; a 
"massive" sandstone usually suggests a gentle environment of deposition.  Also, 
small bones were dislocated; we found them a few feet away from the core of the 
body.  This suggests that the body was not buried after death, which allowed a 
few parts to "migrate" downstream.

Another interpretation to your original observations is that there was not much 
of a gnawing-animal population at the time.  I'm not sure if Mesozoic multis 
were strong enough to destroy the bones as readily as modern rodents