Abstract: The environmental conditions that existed during the period between 45 and 30 ka are of vital importance for addressing the transition between the Middle and Upper Paleolithic. It seems to be a hiatus of
Paleolithic populations, a "no (hu)man's land" in Central Iberia, coinciding with the mid part of Marine
Isotope Stage (MIS) 3, between 42 and 28 cal kyr BP. This break in the archaeological record makes it
difficult to address this period paleoecologically. Here we present a new cave site, Portalon del Tejadilla
(Segovia), dated to a period roughly between ~34.2 and 40.4 cal kyr BP in which cold-adapted faunas,
such as woolly rhinoceros and giant deer, have been recovered in a hyena den site context. This site is
located in Central Iberia, and more specifically, on the southern edge of the northern Plateau, an unexpected region for the presence of these faunas during the MIS 3. These new findings extend the
geographical distribution of several species, including Coelodonta antiquitatis and Megaloceros giganteus.
Furthermore, they document a climatic deterioration (colder and dryer) during the mid MIS 3 in Central
Iberia in one of the coldest and driest episodes of the Late Pleistocene. Portalon del Tejadilla fills this
temporal gap and provides valuable paleoecological information about the transition between the
Middle to Upper Paleolithic