Dinosaur "sails" in today's lizards...

[Pluto77189@aol.com]

    I've been reading posts from this list for a couple of years or so, on and 
off...  I like that Spinosaurus got publicity from JP3, and I found some of the 
discussions interesting, especially when comparing the sail of spino with other 
animals, dinosayrs included.  

    With spinosaurus, and other sail backed dinosaurs and reptiles, we're 
thrown dozens of reasons for the feature.  It's a temperature regulator, a 
defenzive threat, blah...blah...   And so many people have said(not necessarily 
on this list, I don't think) that the "sail" is not seen in nature nowadays.  
This isn't true.  

   Tall dorasl spine s is actually very common in lizards, in South American 
Basilisks and sailfin dragons.  They are even more common in Chameleons--Some 
of which have EXTREMLY similar sails to Spinosaurus, and many of which have 
them nearly identical to the Acrocanthosaurs(I get a good look at the mounted 
Acro almost every day.  They have one at the NC mueseam of natural history, and 
you can see it from the street.)

I don't have the links "on me" but if anyone's interested,  I can post some 
links to some pics of certain Chameleo species that demonstrate the "sail":  
C.cristatus, C. montium, C. quadricornis, C. Melleri

And some with the "high back" that Acro probably had: 
C. deremensis(I have a breeding group of these) 

The "high back" seems to be a camoflage/display tactic, with deremensis, it 
helps make them look more like a leaf from the side, but it also makes them 
look much bigger(especially in the males)

The "sails" in the other species are(mostly) sexually dimorphic, although 
present in the females to a lesser extent, and are used in displays.  They are 
there for both attracting mates and scaring off rivals.  

Aside from the "use" of these attributes, you get a good idea of what the thing 
actually looked like in the dinosaurs.  
In C. deremensis, the effect is that of a high, narrow back.
In C.cristatus, the effect is more of a sail than even spinosaurus had, 
complete with vertebral spines visible through the skin.  

Lemme see if I can find some really good pics.  
Eric A