Discover the Aquitanian Stage and Explore the Fossils and Geodiversity That Shaped Our Planet

Sip back and discover the Aquitanian Stage dated to between 23.03 – 20.44 million years ago and explore the earliest division of the Miocene Epoch. The Aquitanian Stage is named from studies of the Aquitaine Basin in France and is a stage that follows the Late Oligocene Chattian and precedes the Burdigalian. The Aquitanian Stage tells a story of a global shift toward cooler and drier climates. The official boundary is defined by the GSSP in the Rigoroso Formation at Lemme-Carrosio in the Piedmont Tertiary Basin in southern Piedmont, Italy. Lemme-Carrosio is characterised by an assemblage of calcareous nannofossils such as Sphenolithus sp., Planktonic Foraminifera including Paragloborotalia kugleri, Globoquadrina sp; Benthic Foraminifera and Dinoflagellate Cysts. During the Aquitanian, mammalian evolution accelerated, with new species migrating from Asia and Africa into Europe, including early deer, rodents, and primates, marking significant faunal diversification. Tectonic activity, notably the Alpine Orogeny, shaped European landscapes and created sedimentary basins preserving rich fossil records. Marine ecosystems flourished with diverse planktonic foraminifera, molluscs, and early cetaceans, while climate conditions supported expanding forests and grasslands. The Aquitanian Stage is vital for understanding early Miocene environmental shifts, tectonic influences, and biological evolution.

The Aquitanian Stage spans approximately 2.59 million years and represents the earliest division of the Miocene Epoch within the Neogene Period of the Cenozoic Era. It succeeds the Chattian Stage of the Late Oligocene and precedes the Burdigalian Stage marking the base of the Miocene. This interval is distinguished by a global cooling and a drying trend relative to the warmer conditions of the preceding Oligocene reflecting an important time of climate change.

Named after the Aquitaine Basin in southwestern France where its characteristic rock formations were first studied. The Aquitanian Stage is notable for significant faunal changes including the migration and evolution of new mammal species from Asia and Africa into Europe. These biological shifts provide valuable insights into the diversity of the early Miocene’s ecosystem.

The official Global Boundary Stratotype Section and Point (GSSP) defining the base of the Aquitanian is located not in France but in the Lemme-Carrosio Section of the Rigoroso Formation in the village of Carrosio village within the Piedmont Tertiary Basin.

The Rigoroso Formation located in the Tertiary Piedmont Basin borders the Western Alps and Northern Apennines and is made up of a succession of silty sediments including mudstone, siltstone and sandstone that reflect the presence of turbidity currents. The formation exhibits notable lithologic variability and its deposition is closely tied to regional tectonics with the basin developing in an extensional setting during the late Eocene to early Oligocene and later influenced by Apennine compression. The Lemme-Carrosio section is a approximately 63 meters thick thin-bedded succession of mudstone and siltstone known as the Marne di Rigoroso or Rigoroso Marls. This formation is linked to the Formazione di Rocchetta a formation key for understanding the sedimentary and tectonic evolution of northwestern Italy and particularly the interactions between the Alps and Apennines.

The Apennines are a prominent mountain range that forms the backbone of Italy, stretching approximately 1,350 Km from Liguria in the northwest to Sicily in the south. Running down the center of the Italian peninsula, they separate the eastern and western regions and serve as the source of nearly all of Italy’s rivers, including the Tiber and Volturno. The range is characterised by dramatic peaks and valleys with Corno Grande as its highest point protected areas such as the Corno alle Scale Regional Park preserve the region’s unique landscapes and biodiversity.

The stratigraphic boundary at the Lemme-Carrosio section is marked by the first appearance of the planktonic foraminifer Paragloborotalia kugleri a globally recognisable biozone ratified by the International Commission on Stratigraphy in 1996. The section also features key biostratigraphic markers including calcareous nannofossils including Sphenolithus ciperoensis, S. delphix, and S. capricornutus; planktonic foraminifera like Globoquadrina dehiscens and Globigerinoides altiaperturus, benthic foraminifera such as Uvigerina spinicostata, and dinoflagellate cysts including Ectosphaeropsis burdigalensis and Chiropteridium species.

First introduced by French geologist Charles Mayer in 1858 the Aquitanian Stage is represented by the marine sedimentary sequences in the Aquitaine Basin. Along with marine fossil assemblages terrestrial deposits within this stage contain early Miocene mammals including rodents, early ruminants and primates.

In Europe, the MN1 mammal zone corresponds to the Aquitanian Stage the earliest biozone of the European Neogene mammal stratigraphy corresponding to the early Miocene. It marks the first phase of Miocene mammal fauna after the Oligocene featuring a diverse mix of mammals including insectivores like Galerix symeonidisi (a hedgehog-like insectivore), gliding rodents such as Eomys quercyi and the earliest bovids and cervids. This zone also reflects important evolutionary radiation and animal migrations.

During the Aquitanian, continents began to approximate their modern day configurations although tectonic activity continued to shape the landscape. The Alpine Orogeny was active in southern Europe, as the African and Eurasian plates converged, forming mountain ranges such as the Alps, Carpathians and Dinarides. This mountain building activity created foreland basins that trapped marine sediments and preserved important fossil records.

Meanwhile, the Tethys Ocean was in its final phase of closure and fragmented into the Paratethys Sea that extended from Central and Eastern Europe to Central Asia. The Atlantic Ocean continued its gradual widening through seafloor spreading while subduction-related volcanism was ongoing along the western margins of North and South America in the Pacific.

The Aquitanian climate was generally warm and temperate, representing a rebound from the cooler late Oligocene conditions. This climate allowed the expansion of mixed forests, grasslands, and open woodlands across mid-latitude regions. Vegetation adapted to seasonal patterns, with both deciduous and evergreen plants diversifying alongside the evolving mammalian herbivores and grazers.

Marine ecosystems flourished and tropical reefs developed an in some areas the fossil record reveals the earliest representatives of modern cetacean families such as dolphins and baleen whales. Sharks and rays were widespread, indicating a productive marine food web.

The Aquitanian Stage of the early Miocene tells a story of diverse sedimentary environments, from marine carbonates and deltaic deposits to terrestrial sandstones and paleosols, with key European basins preserving cyclic limestones and marl. Fossil-rich lakes in the South of Asia and East Africa reveal early Miocene flora and fauna highlighting mammalian evolution.