This bone is a humerus (upper arm bone) of a long necked brachiosaur. It takes a lot of work to clean a bone this big.
We are currently studying a new species of an ornithischian dinosaur (lower jaw pictured above). It is the smallest known dinosaur from North America and one of the tiniest dinosaurs ever found.
Witness Dinosaur Encounters Saturdays and Sundays in the North American Mammal Hall, Level 2.
Dinosaurs constitute one of the most successful groups of terrestrial vertebrate animals ever to inhabit the Earth. For over 160 million years in the Mesozoic Era, large dinosaurs dominated every terrestrial niche, appearing during the later part of the Triassic, flourishing through the Jurassic, and surviving until the very end of the Cretaceous. A wealth of evidence has been accumulated in support of the notion that a group of carnivorous dinosaurs, theropods known as maniraptorans, contain the predecessors of birds–65 million years after the Cretaceous mass extinction exterminated the last surviving species of large dinosaurs, their living descendants (birds) continue to be a main component of most terrestrial ecosystems.