Hominid Cave at Thomas Quarry I (Casablanca, Morocco): Recent findings and their context

The Thomas Quarry I locality was made famous in 1969 with the discovery of a human half-mandible in a cave. In 1985, further investigations revealed the presence of a Lower Acheulean assemblage in lower units of the section. From 1988 onwards, modern controlled excavations took place within the framework of the Franco-Moroccan co-operative project " Casablanca" Acheulean artefacts, a rich mammalian fauna and four hominid teeth have been excavated from the cave. The faunal set indicates an open woodland environment. Carcasses were processed by carnivores, but cut-marks are absent, which raises the question of any human role in the bone accumulations. Stone knapping was mainly oriented towards flake production and a few bifaces have been imported into the site. Laser ablation ICP-MS dating combining the ESR and U-series data for the modelling of the U-uptake has given an US/ESR age of 501⁺⁹⁴_-76 ka for a human premolar while new OSL measurements yielded an age of 420 ± 34 ka for sediments immediately above the dated tooth and 391 ± 32 ka below. Nevertheless, biostratigraphy and lithostratigraphy point towards a greater antiquity.