Psychic Psquirrel Ping.
No gastric mill in sauropod dinosaurs:Polished pebbles occasionally found within skeletons of giant herbivorous sauropod dinosaurs are very likely to be gastroliths (stomach stones). Here, we show that based on feeding experiments with ostriches and comparative data for relative gastrolith mass in birds, sauropod gastroliths do not represent the remains of an avian-style gastric mill. Feeding experiments with farm ostriches showed that bird gastroliths experience fast abrasion in the gizzard and do not develop a polish. Relative gastrolith mass in sauropods (gastrolith mass much less than 0.1% of body mass) is at least an order of magnitude less than that in ostriches and other herbivorous birds (gastrolith mass approximates 1% of body mass), also arguing against the presence of a gastric mill in sauropods. Sauropod dinosaurs possibly compensated for their limited oral processing and gastric trituration capabilities by greatly increasing food retention time in the digestive system. Gastrolith clusters of some derived theropod dinosaurs (oviraptorosaurs and ornithomimosaurs) compare well with those of birds, suggesting that the gastric mill evolved in the avian stem lineage.
new evidence from analysis of
gastrolith mass and function in ostriches
Oliver Wings and
P. Martin Sander
Proceedings of the Royal Society B: Biological Sciences
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Warm-Blooded Dinosaurs?
http://biology.fullerton.edu/biol404/hol/hol_ch13.html
I'm thinking we just don't want to go there.
I don't want to give the NYT the hits. Where do squirrels come in?
Psychic Psquirrel Ping.
Is there anything you can tell us about the [ahem] stones?