I don't think this really needs a description... it's a tyrannosaur about to chomp an ornithomimid (obviously), in Late Cretaceous Mongolia. I do believe there is a similar drawing by Bakker in The Dinosaur Heresies, but my copy is in Australia. If anyone has a copy it would be great if you could send a scan/photo of the drawing to me (john.a.conway@gmail.com). I want to see how it compares.
This painting is actually ANIMOOTED, but dA's pathetic video size won't show that to any great effect, so here's the still version.
Also love the color pallette, the tiny hints of orange and red, very cool.