Old 05-27-2009, 07:41 PM
  # 179 (permalink)  
gneiss
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Originally Posted by Bamboozle View Post
I was hoping you could tell me how old it is. Actually, I knew you could tell me how old it is.


I read that these things went with the dinos...and I thought that was curious. I don't know much about that period. I'll have to do some more info digging. Thanks again, gniess.
You're welcome. I had fun with it. Although, I asked Dr. Google for the first appearance of ammonoids. For the record, it was late Cambrian, somewhere around 450 to 500 million years ago. I'm not that good, I just have reference materials and a vague idea of where to start looking.

If my guess is correct, your fossil is somewhere between 65 million and 145 million years old (probably on the younger end of the scale, 65 to 75 million years). And it's beautiful!! Most of the ammonids you find look more like this one I found last summer in Colorado:

You can see the coil shape, but it's not nearly as nicely preserved as what Bam has. For scale reference, my rock hammer is about a foot long.

It actually makes a lot of sense that whatever killed the dinosaurs would also kill many other types of creatures. Whatever it was, to cause a mass extinction would have changed climates/environments worldwide in a major way and ecosystems would have broken down quickly. That was actually kind of small as mass extinctions go. For comparison: at the end of the Cretaceous (the end of the age of dinosaurs) around 60% of life went extinct. At the beginning of the age of dinosaurs, the end of the Permian/beginning of the Triassic, about 95% of life went extinct. Ammonoids survived the Permian-Triassic extinction but not the smaller Cretaceous-Tertiary extinction.

It seems reasonable, given findings in the last 10 years or so, that to some extent dinosaurs live on as birds. There have been a number of dinosaur skeletons found with skin and feathers preserved. The popular hypothesis of a major meteor impact has been called into question in the last few weeks, even, so who knows! The new study could be wrong, or it could actually be a new finding. We probably won't be able to make a decent assessment for years.

Last edited by gneiss; 05-27-2009 at 08:05 PM. Reason: Adding some cautionary language to my science.
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