Comments on: Dinosaur Turnover http://blogs.smithsonianmag.com/dinosaur/2012/08/dinosaur-turnover/ Where Paleontology Meets Pop Culture Sat, 22 Dec 2012 16:48:38 +0000 hourly 1 http://wordpress.org/?v=3.4 By: Thomas R. Holtz, Jr. http://blogs.smithsonianmag.com/dinosaur/2012/08/dinosaur-turnover/comment-page-1/#comment-6781 Thomas R. Holtz, Jr. Mon, 06 Aug 2012 13:40:09 +0000 http://blogs.smithsonianmag.com/dinosaur/?p=8205#comment-6781 Although I am quite impressed by this paper, there are some issues with comparing this sequence to any other sequence in dinosaur paleontology. Basically, they are looking at the "perfect storm" for recording dinosaurian fossils: an extremely active orogeny, an extremely narrow alluvial wedge in which to dump the sediment (and thus, in combination, a very high rate for recording the presence of fossils), coupled with a currently uploaded region in an arid zone for which access is extremely easily for researchers (allowing for easier discovery of the fossils there). I wonder if other sections of dinosaur history were equally as well produced and sampled if they would have comparable levels. (The Kaiparowits might be a good case: but you need to have comparable levels of field hours of collecting to make it equivalent). That said, I think this is a really good case for turnover pulses in Mesozoic terrestrial ecosystems. Although I am quite impressed by this paper, there are some issues with comparing this sequence to any other sequence in dinosaur paleontology. Basically, they are looking at the “perfect storm” for recording dinosaurian fossils: an extremely active orogeny, an extremely narrow alluvial wedge in which to dump the sediment (and thus, in combination, a very high rate for recording the presence of fossils), coupled with a currently uploaded region in an arid zone for which access is extremely easily for researchers (allowing for easier discovery of the fossils there).

I wonder if other sections of dinosaur history were equally as well produced and sampled if they would have comparable levels. (The Kaiparowits might be a good case: but you need to have comparable levels of field hours of collecting to make it equivalent).

That said, I think this is a really good case for turnover pulses in Mesozoic terrestrial ecosystems.

]]> By: Mark Robinson http://blogs.smithsonianmag.com/dinosaur/2012/08/dinosaur-turnover/comment-page-1/#comment-6776 Mark Robinson Sat, 04 Aug 2012 02:40:46 +0000 http://blogs.smithsonianmag.com/dinosaur/?p=8205#comment-6776 "...although the picture gets a little muddier at these levels." - I bet that's due to the encroaching Western Interior Seaway. ;-) “…although the picture gets a little muddier at these levels.” – I bet that’s due to the encroaching Western Interior Seaway. ;-)

]]> By: Herman Diaz http://blogs.smithsonianmag.com/dinosaur/2012/08/dinosaur-turnover/comment-page-1/#comment-6773 Herman Diaz Fri, 03 Aug 2012 22:11:11 +0000 http://blogs.smithsonianmag.com/dinosaur/?p=8205#comment-6773 "and the hadrosaurs Lambeosaurus clavinitialis and Lambeosaurus lambei show up in the lower zone but pass through into the second zone as well." You'd think that'd be expected given that, last I checked ( http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0031295 ), the former is probably a synonym for the latter. "In order to live alongside one another, then, we can assume that there was some kind of niche partitioning–the dinosaurs were adapted to have restricted diets or live in particular habitats as a result of their competition for resources." Doesn't that count as evidence for the "turnover pulse hypothesis"? “and the hadrosaurs Lambeosaurus clavinitialis and Lambeosaurus lambei show up in the lower zone but pass through into the second zone as well.”

You’d think that’d be expected given that, last I checked ( http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0031295 ), the former is probably a synonym for the latter.

“In order to live alongside one another, then, we can assume that there was some kind of niche partitioning–the dinosaurs were adapted to have restricted diets or live in particular habitats as a result of their competition for resources.”

Doesn’t that count as evidence for the “turnover pulse hypothesis”?

]]>