Lystrosaurus, skull, a dicynodont Stegosaurus and the Psittacosauridae

and the Psittacosauridae

but its teeth

chemical alteration has replaced the original skeletal hard parts of the fossil with pyrite

Sauropod of the Jurassic Dry Mesa

slate was quarried for hundreds of years and is still quarried today up to 38 feet in depth

Lystrosaurus, skull, a dicynodont Stegosaurus and the PsittacosauridaeLystrosaurus (meaning "shovel lizard", was a genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica, India, and South Africa. Four to six species are currently recognized, although from the 1930s to 1970s the number of species was thought to be much higher. Being a dicynodont, Lystrosaurus had only two teeth, a pair of tusk like canines, and is thought to have had a