Amazing Appalachiosaurus Arms

[acp002@mcdaniel.edu]

I recently came across the webpage for the McWane Science Center's exhibit on 
Alabama dinosaurs (http://www.mcwane.org/exhibits/alabama_dinosaurs).  
Unsurprisingly, Appalachiosaurus is the most prominently featured animal.  At 
the bottom of the page, there is a very intriguing video on the taxon, 
prominently featuring its forearms.  

The cast skeleton on display has incredibly elongate, robust, three-fingered 
forearms.  The arms are almost absurd; they seem proportionally longer than 
those of any tyrannosauroid or carnosaur.  This cast seems to be one from 
Triebold Paleontology (featured at: 
http://trieboldpaleontology.com/specimens/appalachiosaurus.html), so the arms 
may well be standard issue for Appalachiosaurus casts.

The initial description certainly doesn't attribute forearm material to this 
animal, and the paper's reconstruction looks like a relatively average 
tyrannosaurid.  Could this be a new speculation based on the purported basal 
position of Appalachiosaurus in the Tyrannosauroidea, thus giving it more basal 
coelurosaurian/Ornitholestes-type arms? 

Adam Pritchard
acp002@mcdaniel.edu