dinosaurs that don’t pee?

January 06, 2008

We saw Walking with Dinosaurs on last Sunday before New Year’s in the San Jose Arean. It was really fun to see giant dinosaurs in action, even if you could tell that they were puppets and huge contraptions on rollers. The light show was inventive and created a wonderful atmosphere with few props and stage settings.

For the most part, they did a good job of explaining what was fairly well established vs. what was not well understood, for which the paleontologists had theories that were mostly guesswork. However, I was puzzled by one statement about the plateousaurus which lived in the very dry Triassic period. The narrator reported of this dinosaur that “to conserve liquid, she doesn’t sweat, or even pee.” How, I wondered, could they possibly know that from the fossil record?

I could read about Dinosaurian physiology with interesting discussions of whether they were warm or cold-blooded, but I could find no reference of what we know about dinosaur sweat or urine. I did find a site where I could ask a paleontologist. I was thrilled when Patricia Hester wrote back quite quickly:

“That’s a very good question. The statement could be derived from the
environmental data collected from the rocks where the fossil material was
discovered, the understanding of the climate during the time the animals
lived and the configuration of the continents during the Triassic. From
my understanding, the fossil material is all from Europe. The sedimentary
rocks provide data that allow for interpretation of what is called ” the
depositional environment” where the rocks were formed. That’s why ” the
context” (the rocks) where the fossil material is discovered is important
to document when researchers discover fossils.

“The depositional environments, continental configuration and climate
suggest that these animals inhabited a dry and hot world. The narrator may
have been making the “leap” from animals inhabiting similar climates in
modern ecosystems conserve moisture by reducing water loss to this extinct
early dinosaur. There are modern desert mammals that don’t “pee” any
liquid.. but eliminate wastes in solid form.

“I’m not aware of any fossil evidence from the bones themselves that would
provide this interpretation. However, there is always current research
ongoing and it’s hard to keep up with it all. Since bones are living
tissue during an animals life, there certainly could be something I don’t
know that could support the statement from the movie. I just don’t know
about it.

“The web site, http://jan.ucc.nau.edu/~rcb7/Triassic.html, shows what earth looked like during the late Triassic
… and Europe was near the center of a large continent.. as a result..
very dry.”

Now, I wonder what modern day animals don’t sweat or pee :)

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