This is the first time since the 1970s that Pietro has visited this exhibit. Rather than remove the entire fossil deposit, the excavators here left about 20% of the deposit in-situ so that visitors can see what it looks like.That said, it is a really large exhibit. And the fossil assemblage is unusually dense. It may have been a riverbend where both corpses and their scavengers concentrated.That’s a lotta big bones jumbled together. Among big vertebrates, a distinguishing feature of dinosaurs is the open-hole hip socket, which is visible here just up and right from the center of the image.The preserved outcrop is several hundred feet long.Fossil density is lower on the left side, but these bones were less disturbed before being buried and fossilized. Therefore, whole intact skeletons are visible in their original, ‘articulated’ arrangement.Allosaurus fragilis. A larger, older specimen. Unlike T.Rex, Allosaurus had substantial arms and grabby claws.Like other therapods it has many skull-holes which resulted in an effective compromise between skull strength and weight. It also has a little ridge above the eye, and what appear to be blood-vessel holes just above the teeth. These may have supplied blood to lips covering the teeth.Elongated ilium and pubic bones provided well-leveraged attachment-points for leg muscles. The overall slender proportions of the leg-bones suggests a very effective runner.Well-evolved hips for horizontal-body bipedalism, counterbalanced by a beefy tail.Dominant three-toed foot. Back at the Visitor’s Center is a wall of children’s drawings. We all agreed that this fellow Max’s drawing expressed the idea best: arrr!
