Re: Quadraped Sailbacks-All non-dinos?

[John Schneiderman <dino@revelation.unomaha.edu>]

On Tue, 25 Apr 1995 cristeaj@pt.Cyanamid.COM wrote:

> 
>      I was recently talking to an Earth science high school teacher about 
>      how he teaches his kids about what makes a dinosaur different from 
>      other prehistoric animals.  He told me that he uses "quadraped 
>      sailbacks" (i.e. Dimetridon) as one discrimination as to what is _not_ 
>      a dinosaur.  I told him that there were other (better) ways to 
>      discriminate a dinosaur such as: (1) Lived only in the Mesozoic Era, 
>      (2) Walked with legs directly under the body (not sprawled), (3) Lived 
>      primarily on land, (4) Had unique anatomical structure (i.e. hips, 
>      etc), and (5) All dinos were reptiles.  
>      
>      Although he uses some of the above, he still put in "Quad. Sailbacks". 
>      Are there any quadraped sailback dinos?  I think the five 
>      qualifications above are enough to qualify for dinosaurian without the 
>      confusion of "Quad. Sailbacks".  What do you think?  Thanks!
>      
There are examples of "sails" in dinosaurs, although not to the level of 
development seen in non-dinosaurs creatures such as Dimetrodon.
Here are some examples:
Bipedal---> Spinosaurus, Acrocanthosaurus, Altispinax
Functionally bipedal--> Ouranosaurus, Hypacrosaurus
Quadrapedal--> Amargasaurus, Dicraeosaurus

---John Schneiderman (dino@revelation.unomaha.edu)