When I started developing the Chuhuac the took form as numerous sketches and scribbles, trying to figure out just what sort of shape and overall effect I wanted. A lot of thought was put into just how they would move, what they would wear, how they would hold their weapons, etc..
I didn't spend a lot of time on hard line and details, because these all come out later in the process, but the feel and the lines and the general character of the species was what I was after at this point. In some cases, the aliens looked much less predatory and closer to Gallimimus or perhaps a Struthiomimus but neither of these had the look I was after, even if they were cool on their own. Still other designs had them more or less armored and in some cases looking less dinosaur and a little more fanciful such as in the sketches below.
As time went by I explored some ideas like outrigger heavy weapon pods (right), an idea I abandoned because it seemed too cartoonish, and various degrees of lighter armor and more "spacey" looking weapons (below). The concept started to gel and when I was happy with it, I took my sketches to Chris and he got going on the final concept art.
Art by Eli Arndt