This is a large 1.62" long tooth of Allosaurus fragilis from the Skull Creek Quarry near Dinosaur, CO. It was left partially embedded in the sandstone matrix in which it was found, so that it stands up on it’s own.
Beautiful preserved cell structure in this piece of dinosaur bone from the Morrison Formation of Colorado. The bone has been “agatized”, replaced with silica based compounds. The larger cell structure indicates that it’s most likely from a theropod such as Allosaurus. The bones of sauropods have smaller cells.