Biochronology of Spanish Quaternary small vertebrate faunas

Thousands of fossils of small vertebrates are recorded in one of the most complete stratigraphic sequences of the continental European Pleistocene, in the Sierra de Atapuerca. This sequence, with a few interruptions, spans the last 1.5 million years. The stratigraphic series is recorded in six karstic cavities in the Sierra de Atapuerca. From the oldest record to the most modern one, these are the Sima del Elefante, Gran Dolina, Galería–Zarpazos, Sima de los Huesos, El Portalón and El Mirador. The faunal successions of continental microvertebrates have made it possible to divide the Atapuerca sequence into 7 faunal units (Atapuerca Faunal Units, ATA FUs), which are based on the first and last local appearances of taxa (LO, HO). The Spanish Quaternary small vertebrate faunas are grouped into 5 distinct biozones, from the oldest to the most recent: Allophaiomys pliocaenicus, Allophaiomys lavocati, Allophaiomys chalinei, Iberomys brecciensis and Iberomys cabrerae. These are calibrated with radiometric and palaeomagnetic dating, allowing the proposal of a continental biochronological scale for the Pleistocene of the Iberian Peninsula.