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RE:sauropod feeding*



Stan Friesen wrote:

>Geese are part of a group that largely feeds underwater.  I suspect
>the long neck of the anseriformes may be an adaptation to reaching
>the bottom of a pond.  Besides, even in geese, the neck still isn't
>much langer than necessary to reach the ground.  It is just that the
>geese have a tall *body* rather than long legs.

Sorry, but the Canadian Geese out here in the west graze on the ground. 

I seen them feed at the U.S.G.S. (no lakes around), at the softball 
field near the museum and around City Park near the Museum. Karen Chin 
analyzed some of their dung I sent her and confirmed that it was grass. 

Come to think of it, I used to see them grazing in Schulkil Park in 
Philadelphia when I lived there. Also, I have a goose skeleton and the 
neck is indeed longer than the body.

>This is the feeding style of colobus monkeys, and to some degree, of
>giraffes. A giraffe feeds by pulling selected leaves from the tree
>with its long tongue and flexible lips.

Indeed, a Colobus uses its fingers to selectively pick leaves and
giraffes pluck from individual branches (narrow snout). That is still
considered selective feeding (see W. Leuthold, 1977, African
Ungulates, Springer-Verlag, 307p.)  grazer crops any low plant and may
get several different species per bite (e.g., horse will crop grass
and dandelions at the same time).

>Yes, niche partitioning, naturally.  It is impossible for so many
>sauropods to have co-existed as we see in the Morrison otherwise.
>But it can be done in the trees as much as between trees and ground.
>Giraffes and elephants coexist, and overlap in their feeding heights
>to some degree.  Giraffes are mosre selective, elephants less so.
>Giraffes, on average, feed higher, and elephants tend to feed lower.
>In the same areas there are also baboons, chimpanzees, and in some 
>areas elephants coexist with leaf-eating monkeys.

The problem here is that Stan is mixing different kinds of mammals 
having different life styles. However, note that Stan's examples 
consist of selective feeders. Yes, they do have niche partitioning. 
However, I have been focusing on one group, Sauropoda, and am pointing 
out that Stan has yet explain why diplodocids have a broad, grazing 
type muzzle, while camarasaurids, etc. have a narrow, browsing muzzle. 

>However, there is little (read none) evidence for arboreal leaf eaters
>in the Late Jurassic (multituberculates being seed and fruit eaters).

Actually they may have been omnivores, but that is a side issue (see 
Clemens and Kielan-Jaworowska, 1979, Multituberculata. IN Lillegraven 
et al, Mesozoic Mammals, the first two-thireds of mammalian evolution. 
U. of California Press; Kraus, D., 1982, Jaw movement, dental function, 
and diet in the Paleocene multibuberculate Ptilodus. Paleobiology 
8:265-281).

>>      By the way, at the WAVP meeting, it was demonstrated that the
>> holotype vertebra of Ultrasaurus (brachiosaurid) is a posterior
>> dorsal of Supersaurus (a diplodocid), a pointed conceded by Jensen
>> who at the meeting.
>
>Umm, *which* Ultrasaurus?  The Japanese one?

No, Korean (a footprint).

>or the American one that is more properly called Ultrasauros?

Yes, but since it was reported as Ultrasaurus then I passed it on that 
way.

Kenneth Carpenter
Dept. of Earth Sciences
Denver Museum of Natural History
2001 Colorado Blvd.
Denver, CO 80205
crpntr@ix.netcom.com