SAUROPOD POLING?

[pss1nw@surrey.ac.uk (Nigel Woodger)]

>  I REMEMBER READING ABOUT SOME SAUROPOD FOOTPRINTS WHERE ONLY THE FRONT PRINTS
>WERE VISIBLE. THIS WAS INTERPRETTED TO MEAN THAT THE ANIMAL WAS IN DEEP ENOUGH
>WATER TO BUOY ITS REAR LEGS OFF OF THE LAKE BOTTOM. MY QUESTION IS: IF IT WAS
>DEEP ENOUGH FOR THIS, WASN'T IT ALSO DEEP ENOUGH THAT THE WATER PRESSURE WOULD
>PREVENT THE SAUROPOD LUNGS FROM OPERATING? IS THERE ANOTHER INTERPRETATION OF
>THE PRINTS POSSIBLE? ARE WE SURE THAT THEY ARE _SAUROPOD_ FOOTPRINTS? WEREN'T
>SOME PROSAUROPODS OCCASIONALLY BIPEDAL?
>
>SCOTT HORTON
>GEOPHYSICIST/COMPUTER PROGRAMMER
>
>in a realy good book which I think is called Tracking Dinosaurs and I'm 
afraid I can't remember the author either (My copy is at home and I'm not) 
it is suggested that these fossils may be of "under tracks" that is to say 
not the prints in the top layer of soil at the time the track was made but a 
lower level of soil/clay etc that only preserved the deeper prints of the 
forfeet.

regards
Spike