Richards Spur, at the Dolese Brothers Limestone Quarry north of Lawton, Oklahoma, preserves early Permian fossils in the clay and mudstone fillings of an ancient cave and fissure system cut into much older Arbuckle Limestone. Dating to about 289 to 286 million years ago, the site is unusual because its animals were preserved in narrow vertical cave fills, often with exceptional detail from calcite in a humid cave environment. Its rich, largely terrestrial vertebrate fauna and scarcity of aquatic animals point to a relatively dry upland habitat. Since fossils were first reported in 1932, discoveries there have made it one of Oklahoma’s most important paleontological sites.