12 February 2011
The first illustration is up on the Natural History Museum in London's website. It's an interesting study of two animals feeding. I've seen a larger color version with a third living animal, but have only been able to find a tiny thumbnail (below). It has an NMH watermark though, so it could be on their website somewhere. I also found this just now.
The second image is a unique image that shows a Nanotyrannus fishing a Hesperornis out of a coastal shallow while other Hesperornis dive for safety and a few that even appear almost calm on rocks near the attack. Done in pencil by Tuomas Koivurinne in 2006, it's an awesome study of the subject and the Hesperornis as well.
The next image is almost too active to follow, but you can try anyhow. I haven't found an artist as yet, keep an eye out for me world!
This last image is clearly a painting, artist is still being searched for, and I don't know for certain if it is hanging anywhere public. However, it contains an interesting profile as well as a head on look at the eyes of a Nanotyrannus and is therefore one of my favorite depictions found so far.