Re: Platyhystrix and dinosaur humps/sails

[Dinochandler@aol.com]

Yes, most of the "sail-backed" dinosaurs lived around each other, too, like 
_Ouranosaurus_ and _Spinosaurus_.  Having a hump for a desert living animal 
would probably be advantageous, just look at camels.  But I don't believe 
they have bones in their humps.  Some bison do however have elongated 
vertebra like in _Spinosaurus_ and they support a hump.  Well, to answer your 
question, in the case of dinosaurs it would probably be more beneficial to 
have a hump rather than a sail, but in amphibians, I don't know.  But in 
_Dimetrodon_, the "spines" as we'll call them have a different look to 
them...they're more delicate and seem that they would only support skin, as 
they look similar in _Amargasaurus_, which probably used the sail for 
courtship or possibly defense (not sure about this one).  Back to 
_Dimetrodon_,  since it was a mammal-like reptile, it was probably 
ectothermic, and used a "sail" for heat acquisition.  Dinosaurs, on the other 
hand...
Anybody else have anything to add?

In a message dated 3/6/00 5:32:14 PM Pacific Standard Time, 
m38jeep@hotmail.com writes:

<< I was going through some of my books and came across a picture of the 
 sailbacked amphibian, Platyhystrix. The spines on its back resembled those 
 of Spinosaurus and Ouranosaurus- flat and blade-like. I've never seen its 
 skeleton, just a few illustrations, but I was wondering this: if we were to 
 say dinosaurs have humps because their spines resemble humped mammals, 
 shouldn't we say the same for Platyhystrix? Which would seem more 
 advantageous to an amphibian, a hump or a sail? BTW, it lived around the 
 same time and place as more probable sailbacks like Dimetrodon and 
 Edaphosaurus, which I find rather interesting... >>