Re: Brontosaurus/Apatosaurus

[twilliams@canr1.cag.uconn.edu]

> He has Brontosaurus excelsius and B. louisi in the middle Morrison and
> Apatosaurus ajax at the top.

How bizarre.  John McIntosh (c1990) considered A. ajax and A. 
excelsius to be so similar to each other that the only criterion he could 
use to distinguish the two was adult body size (A. ajax is 10-15% bigger
than A. excelsius).  A. ajax and A. excelsius share the same degree 
of slenderness of theie limb elements; an accessory lamina in 
infrazygapophysial 
cavity of certain cervicals; and forward-directed extensions of the cervical 
ribs.

A. louisae, on the other hand, could be distinguished from the other 
two species by the extreme robustness of its limb elements, and by the 
absence of the vertebral characters listed above.



> 
> He is proposing the genus Eobrontosaurus for his new species from the
> lower Morrison. That paper will be out in our Lower to Mid. Cret.
> Terrestrial ecosystems symposium volume that will be out next fall.
> 
> Jim Kirkland 
> Dinamation Int'l Soc.
> 
> 
>