LATE OLIGOCENE AND EARLY TO MIDDLE(?) MIOCENE LAND PLANTS, UPPER PIUMA MEMBER, SESPE FORMATION, AND FERNWOOD MEMBER, TOPANGA CANYON FORMATION, CENTRAL SANTA MONICA MOUNTAINS, LOS ANGELES COUNTY, CALIFORNIA
One or more arborescent land plant taxa, including the plane tree- or sycamore-like form genus Platanoxylon, occur as petrified wood, including logs at least 2 m in length, at numerous sites in the upper half of the continental Fernwood (middle) Member of the overlying Topanga Canyon Formation. These taxa constitute the Calabasas Peak Motorway Florule. The plant-bearing interval is mostly if not entirely above the level of late Hemingfordian (late early to early middle Miocene) land mammals, including the equid Parapliohippus carrizoensis. Rodent remains occur at a site at or very near the base of the plant-bearing interval, and a specimen of Turritella(?) occurred as float at a site higher in the interval. The overlying marine Cold Creek (upper) Member contains the Temblorian (late early to late middle Miocene) gastropod Turritella temblorensis and is overlain by the Conejo Volcanics (16.0 to 13.4 Ma, middle Miocene).