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Re: dogma of tree feeding sauropods
Greg Paul wrote:
>The animals that do have forked chevrons are the giant ground sloths,
>which very probably used their tails as props when they feed on two
>legs. Sauropods probably did the same thing.
I do not accept the modern dogma that all sauropods were tree feeders.
1) The "skid" chevrons occur in sauropods with very long tails, e.g.,
diplodocids. In the recent remounting of the Diplodocus at the Denver
Museum of Natural History, I discovered that the skid chevrons
practically touch one another. I suspect that functionally the "skids"
were bound with ligaments in order to keep the tail relatively stiff
and off the ground without the use of muscles. 2) The fossil evidence
for trees so tall that sauropods needed to rear up is very piss poor.
There are some large logs in the Morrison, but few indicate 100+ ft
tall trees. Considering that the dominant vegetation was ferns (over
200 species based on pollen, Litwin, pers. com.), I see no need to
invoke sauropods rearing up to feed on 100+ ft trees. 3) the broad,
squared muzzle of diplodocids is more similar to that seen in the hippo
and white rhino, both of wich are low ground cover croppers. It is not
at all like the rounded muzzle of more selective mammalian herbivores
and which is also seen in some sauropods (e.g. camarasaurids). 4) The
long neck of diplodocids would allow them to crop a larger area of
ferns, etc. in order to fuel their large mass. 5) The neck of
camarasaurids does indeed angle shapely upwards due to the wedge shaped
1st dorsal or last cervical (i.e., it is longer along the bottom of the
centrum than across the top). This sauropod was most likely a tree
feeder (perhaps tree ferns when young, conifers when adults).
Dept. of Earth Sciences
Denver Museum of Natural History
2001 Colorado Blvd.
Denver, CO 80205