Nicolas Weis is a visual development artist working for the animation industry (Imagi, Dreamworks). He has put up a video (below) of the art he created for The Croods. You might have seen some of his art in The Art of The Croods.

And below is a video of his personal sketchbook with work from June 2006 to September 2008.

Check out his blog for more content: https://nicolasweis.com/blog/