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Abstract:
Cueva Victoria has provided remains of more than 90 species of fossil
vertebrates, including a hominin phalanx, and the only specimens of the
African cercopithecid Theropithecus oswaldi in Europe. To constrain the
age of the vertebrate remains we used paleomagnetism, vertebrate
biostratigraphy and Th-230/U dating. Normal polarity was identified in
the non-fossiliferous lowest and highest stratigraphic units (red clay
and capping flowstones) while reverse polarity was found in the
intermediate strati graphic unit (fossiliferous breccia). A lower
polarity change occurred during the deposition of the decalcification
clay, when the cave was closed and karstification was active. A second
polarity change occurred during the capping flowstone formation, when
the upper galleries were filled with breccia. The mammal association
indicates a post-Jaramillo age, which allows us to correlate this upper
reversal with the Brunhes-Matuyama boundary (0.78 Ma). Consequently, the
lower reversal (N-R) is interpreted as the end of the Jaramillo
magnetochron (0.99 Ma). These ages bracket the age of the fossiliferous
breccia between 0.99 and 0.78 Ma, suggesting that the capping flowstone
was formed during the wet Marine Isotopic Stage 19, which includes the
Brunhes-Matuyama boundary. Fossil remains of Theropithecus have been
only found in situ similar to 1 m below the B/M boundary, which allows
us to place the arrival of Theropithecus to Cueva Victoria at similar to
0.9-0.85 Ma. The fauna of Cueva Victoria lived during a period of
important climatic change, known as the Early-Middle Pleistocene
Climatic Transition. The occurrence of the oldest European Acheulean
tools at the contemporaneous nearby site of Cueva Negra suggest an
African dispersal into SE Iberia through the Strait of Gibraltar during
MIS 22, when sea-level was 100 m below its present position, allowing
the passage into Europe of, at least, Theropithecus and Homo bearing
Acheulean technology. (C) 2015 Elsevier Ltd. All rights reserved.
