EMAN's recent comments included:
"A geologist friend of mine, Matt Morgan, was documenting piles of dinosaur bones left high "up slope" in North Dakota apparently deposited there way above normal sea level by any of several tsunami surges from the K-Pg event. Essentially, the tsunami swept up the populations of land based dinosaurs living at the edge of the great inland sea which occupied the interior of North America at the time. We tend to forget that dinosaur skeletons are rare --in general-- outside ash falls, river whirl pool deposits and marl beds. The first dinosaur skeleton found in the US was found in a marl bed in New Jersey. I think this pattern is insightful as to why dinosaur skeletons are not more common."
Tsunamis are known to have moved huge rocks upward at sea coasts, but it is hard to imagine how a tsunami could sweep up "populations" of dinosaurs and selectively concentrated their bones from the other debris. I've seen a description of densly paciked dinosaur bones explained as the result of storm-flood events that swept up a herd of animals or resulted from them trying to cross a swollen river. Would be interested to know how the tsunami-bone bed connection is made in this case. .
Eman also commented as follows on my use of the mass bison kills in the 1800s as an example of how quickly bones will disappear if left unburied " Actually these bones were gathered up into huge piles and railroaded to Chicago to be ground into fertilizer. Google Bison /Buffalo Bone Fertilizer industry."
Hmm. Thanks for the info. I had not heard that part of the story, and I will have to be a little more careful about citing other people. The principle is still valid, though; a claissic study on mammal bones exposed at the surface in Kenya found that "Most bones decompose beyond recognition in 10 to 15 yr" .http://www.jstor.org/discover/10.2307/2400283?uid=3739920&uid=2129&uid=2&uid=70&uid=4&uid=3739256&sid=21102098550347
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