A specimen of the ammonoid Perrinites Böse, 1919, was collected from the McCloud Limestone east of the summit of Tombstone Mountain, Shasta County, California. This is the first record of the genus in California, an important addition to the meager Permian cephalopod fauna of the state previously reported by Miller, Furnish, and Clark (1957) and Wilson (1984). It was found 1,100 feet (335 m) above the base of the formation in a coarse-grained limestone (Los Angeles County Museum of Natural History, Invertebrate Paleontology Section locality 6184) within fusulinid zone H of Skinner and Wilde (1965), considered to be late early or early middle Leonardian in age.
Mesoscale Controls on the Shasta County Convergence Zone