Micromammal-based paleoprecipitation estimates for the late Middle and early Late Miocene record of the Vallès-Penedès Basin (Catalonia): Implications for primate habitats

Abstract The densely sampled and well dated late Aragonian to Vallesian succession (late Middle to early Late Miocene, 12.5–9.0 Ma) of the Vallès‑Penedès Basin (VP) in Catalonia has yielded one of the richest primate records in Eurasia, including hominoids and pliopithecoids. Here we present high‑resolution mean annual precipitation (MAP) estimates derived from the ecological structure of small mammal assemblages to infer the paleoclimate and habitats associated with these primates. Our approach uses the relative abundance of arboreal and insectivore taxa as a paleoprecipitation proxy, producing robust results when sampling is sufficient. MAP values generally cluster around ~1,000 mm with low seasonality. Combined with mean annual temperature (~17–18 °C), this suggests a transitional climate between humid subtropical and Mediterranean regimes. These conditions would have supported diverse environments—subtropical evergreen broadleaf and mixed mesophytic forests interspersed with drier woodlands—consistent with the arboreal locomotor adaptations and inferred dietary preferences of VP primates. We find no evidence for distinct habitat partitioning between hominoids and pliopithecoids, nor for significantly more humid environments during primate‑bearing intervals. Climatic parameters remained relatively stable even through major faunal turnovers such as the Vallesian Crisis (~9.7 Ma), indicating that local extinction of hominoids and other taxa was likely not driven by abrupt climate change, but rather by longer‑term climatic deterioration or subtle environmental perturbations that affected the marginal habitats to which these species may have been restricted.