The first
phosphate deposits in Quercy were discovered in 1869 and published by Daubré and Trutat independently in 1871.[4] The first fossils from the formation were described by Delfortie (
1872) and Gervais in the same year and extensively studied by Filhol from
1877 onwards. The first geologic investigation of the formation was performed by Thévenin in 1903, and apart from a description by Gèze in 1938, the paleontological richness was not studied until a team of researchers of the
Universities of Montpellier and Paris visited the site in
1965.[5]
The
karstified phosphate deposits are found from the
Lot and
Célé river valleys in the north to the left bank of the
Aveyron in the south and from the
Villefranche Fault in the east to the
lacustrine deposits of the
Aquitaine Basin in the west. The formation is found in fissures (karst) incising
Jurassic and
Triassic rocks east of
Cahors.[6] The age of the fossiliferous unit, in which almost 12,000 specimens were found ranges from the MP16 to MP28 zones of the
European land mammal age classification.[5] These ages correspond to the latest
Bartonian to
Chattian, from about 38 to 25 Ma.[7]
Paleontological significance
Paleogeography of the Late Eocene to Oligocene with biodiversity of the Quercy PhosphoritesExceptional preservation of nerves, digestive tract and stomachal content in the frog-eating salamander Phosphotriton sigei
The Quercy Phosphorites Formation is a highly
fossiliferous unit designated as a
Lagerstätte due to the excellent preservation of fossils. The
phosphorite conserves up to the nerves, digestive tract and stomach content,[8] insect larvae and other elements of the paleobiology in the formation. Nearly all Quercy fly pupae were preserved as isolated endocasts, of which many were still covered by the puparium, the hardened skin of the last larval instar.[9] The formation also straddles the
Grande Coupure and shows diversity changes (number of species) of frog, salamander, lizard and snake fossil records across the formation.[10] It is assumed that the Quercy arthropods fossilized by a rapid fixation by phosphate-rich water followed by encrustation and mineralization.[11]
Fossil content
The following fossils have been reported from the formation:[1][2][12][13]
Hugueney, M.; Maridet, O. (2017), "Evolution of Oligo-Miocene talpids (Mammalia, Talpidae) in Europe: focus on the genera Myxomygale and Percymygale n. gen", Historical Biology
Tissier, J.; Rage, J.-C.; Boistel, R.; Fernández, V.; Pollet, N.; García, G.; Laurin, M. (2016), "Synchrotron analysis of a 'mummified' salamander (Vertebrata: Caudata) from the Eocene of Quercy, France", Zoological Journal of the Linnean Society, 177: 147–164
Mennecart, B.; Métais, G. (2015), "Mosaicomeryx gen. nov., a ruminant mammal from the Oligocene of Europe and the significance of 'gelocids'", Journal of Systematic Palaeontology, 13: 581–600
Laloy, F.; Rage, J.-C.; Evans, S. E.; Boistel, R.; Lenoir, N.; Laurin, M. (2013), "A Re-Interpretation of the Eocene Anuran Thaumastosaurus Based on MicroCT Examination of a 'Mummified' Specimen", PLoS ONE, 8: e74874:1
Schmied, Heiko; Schwermann, Achim H.; van de Kamp, Thomas; dos Santos Rolo, Tomy; Baumbach, Tilo (2013), Inside the Clown. Synchrotron X-ray microtomography reveals extraordinary details of internal and genital structures of 30 million old beetles, Joachim Reitner, Yang Qun, Wang Yongdong and Mike Reich (eds.) Palaeobiology and Geobiology of Fossil Lagerstätten through Earth History, pp. 1–218,
ISBN978-3-86395-135-1
Vianey-Liaud, M.; Schmid, B. (2009), "Diversité, datation et paléoenvironnement de la faune de mammifères oligocène de Cavalé (Quercy, SO France) : contribution de l'analyse morphométrique des Theridomyinae (Mammalia, Rodentia)", Geodiversitas, 31: 909–941
Lavrov, A. V (2007), "New Species of Paroxyaena (Hyaenodontidae, Creodonta) from Phosphorites of Quercy, Late Eocene, France", Paleontological Journal, 41: 298–311
Blondel, C (2005), "New data on the Cainotheriidae (Mammalia, Artiodactyla) from the early Oligocene of south-western France", Zoological Journal of the Linnean Society, 144: 125–166
Peigné, S (2003), "Systematic review of European Nimravinae (Mammalia, Carnivora, Nimravidae) and the phylogenetic relationships of Palaeogene Nimravidae", Zoologica Scripta, 32: 199–229
Peigné, S (2001), "A primitive nimravine skull from the Quercy fissures, France: implications for the origin and evolution of Nimravidae (Carnivora)", Zoological Journal of the Linnean Society, 132: 401–410
Peigné, S.; Brunet, M. (2001), "Une nouvelle espèce du genre Eusmilus (Carnivora: Nimravidae) de l'Oligocène (MP 22) d'Europe", Geobios, 34: 657–672
Mourer-Chauviré, C (1989), Les Caprimulgiformes et les Coraciiformes de l'Éocène et de l'Oligocène des phosphorites du Quercy et description de deux genres nouveaux de Podargidae et Nyctibiidae, Acta XIX congressus internationalis ornithologici, pp. 2047–2055
Rage, J.-C (1988), "The oldest known colubrid snakes. The state of the art", Acta Zoologica Cracoviensia, 31: 457–474
Sudre, J (1984), "Cryptomerix Schlosser, 1886, Tragulidé de l'oligocène d'Europe; relations du genre et considérations sur l'origine des ruminants", Palaeovertebrata, 14: 1–31
Hartenberger, J.-L.; Vianey-Liaud, M. (1978), "La poche a phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien Superieur. 13. - Rongeurs", Palaeovertebrata, 8: 313–318