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RE: sauropod necks-buckaroobwana is back! ha ha ha ha ha !!
At 04:55 PM 10/8/99 +0100, Jarno Peschier wrote:
>So, if I understand this correctly, this would signify that Camarasaurus was
>completely incapable of drinking water from ground level or below? If the
>cervical vertebrae have to be disarticulted just to get the neck horizontal,
>how could it go even lower?
That is a very good point, I hadn't thought of that. Hmm... The neck
must have been capable of *some* ventral flexion. These vertebrae had to be
disarticulated in order to make the neck straight, and take out natural
"kinks" in the structure. With them articulated, you might be able to bend
the neck a little at each vertebral articulation, getting a smooth curve
down (albeit from a dorsally directed shoulder region). Try this analogy:
If you take a letter "s" and straighten it out, you'll be bending it
the most in two places (the apices of the curve). You can spread this
distortion out along the entire length of the letter, a little bit over
each segment of the line. The result is a very gently curved "s" shape,
looking a lot more like a sinusoidal curve. It's not as long as your
straight line, but there is a lot less strain.
Alternately, I suppose the animals could have kneeled. Or could
they? Matt, any ideas? Didn't someone (Greg Paul?) illustrate sauropods
kneeling to drink?
There is always the possibility that my interpretation is completely
wrong. Understandably, I don't think so, but I certainly wouldn't go around
basing a theory on it. The obvious thing to do is to go and study one of
these guys and carefully document the vertebrae. Unfortunately, I have a
thesis to write. Anyone else up for it? :)
>So how then did Camarasaurus get the water that it would certainly have needed?
>Or is my "would certainly have needed" is error, with dinosaurs having a
>non-permeable skin (???), eating vegetable matter with enough water content to
>sustain them (???) and expending so little water via waste disposal?
Hmm... all animals need water. Some desert-dwelling animals get all
the water they need from metabolic water, and don't need any outside water.
However, to my knowledge, these are very SMALL animals. Here's a good
question for your local botanist: how much water would plant matter
available to a high-browser actually contain? I had always assumed that the
most watery fronds were down low, and if _Camarasaurus_ ate those, the point
is moot. If there isn't much water in higher leaves and twigs, then the
theory doesn't hold much... um... doesn't help.
True, the excretion of uric acid (instead of urea) in reptiles is
believed to be an adaptation for water conservation. It is parsimonious to
presume that sauropods excreted this substance. However, it was my
understanding that, water-proof or not, all terrestrial animals lose water
through respiration, evaporation from moist exposed tissues (eyes, mouth,
bodily orofices, etc.). This would explain why I've seen members of so many
different reptile clades drinking water. So I feel confident in concluding
that _Camarasaurus_ probably did drink water.
How did it drink? I dunno, maybe some weird pterosaur would scoop up
water in its gular sack and dump it down the camy's throat in exchange for
being allowed to lay its eggs in folds of skin along the sauropod's back.
Ok, you can laugh, but I ain't the one suggesting they didn't drink water. ;)
At 09:18 AM 10/8/99 -0700, Dan Bensen wrote:
>I wondered about that too, when I read the Discovery article. Did Camarasaurus
>live in a dry, desert-like environment? Did its ancestors? Maybe, the
I believe the Morrisson Formation is hypothesized to have been laid
down under arid conditions. However, since it is largely a fluvial deposit,
and since I have heard of many sauropod skeletons being recovered from flood
or channel deposits, I doubt _Camarasaurus_ was hurting for access to water.
It's ancestors, well, that's a different issue.
>water-saving adaptations nessisary for living in a desert would have allowed
>Camarasaurus to develope a neck that reached higher than it could otherwise.
What would it be eating in the desert that was so high in the air?
For that matter, I believe _Camarasaurus_ has, proportionately, the shortest
neck of any Morrisson sauropod. Still, it is an interesting hypothesis. :)
Jonathan R. Wagner, Dept. of Geosciences, TTU, Lubbock, TX 79409-1053
"Why do I sense we've picked up another pathetic lifeform?" - Obi-Wan Kenobi