Quercy Phosphorites Formation Explained

Quercy Phosphorites Formation
Type:Formation
Age:latest Bartonian-Late Oligocene
~
Period:Oligocene
Prilithology:Phosphorite
Namedfor:Quercy
Namedby:Thévenin
Year Ts:1903
Region:Occitanie
Country:France
Coordinates:44.3°N 1.6°W
Paleocoordinates:42.8°N -2°W
Overlies:Fissure fillings in karstified Jurassic and Triassic rocks

The Quercy Phosphorites Formation (French: Phosphorites du Quercy) is a geologic formation and lagerstätte in Occitanie, southern France. It preserves fossils dated to the Paleogene period (latest Bartonian to Late Oligocene),[1] [2] or MP16 to MP28 zones of the European land mammal age classification, ranging from approximately 38 to 25 Ma.

It qualifies as a Lagerstätte because beside a large variety of mammals, birds, turtles, crocodiles, flora and insects, it also preserves the soft tissues of amphibians and squamates, in addition to their articulated skeleton in what has been called natural mummies.

The genera Quercylurus, Quercymegapodius, Quercypsitta, Quercypodargus, Quercycerta and Quercygama, and species Mosaicomeryx quercyi, Robiacina quercyi, Palaeophyllophora quercyi, Archaeomys quercyi, Eomys quercyi, Eucricetodon quercyi and Tarnomys quercynus, as well as the lizards Paraplacosauriops quercyi and Pseudolacerta quercyini and the insect Palaeortona quercyensis were named after the formation.

Description

The first phosphate deposits in Quercy were discovered in 1869 and published by Daubré and Trutat independently in 1871.[3] 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.[4]

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.[5] 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.[4] These ages correspond to the latest Bartonian to Chattian, from about 38 to 25 Ma.[6]

Paleontological significance

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,[7] 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. 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.[8] It is assumed that the Quercy arthropods fossilized by a rapid fixation by phosphate-rich water followed by encrustation and mineralization.[9]

Fossil content

The following fossils have been reported from the formation:[1] [2] [10] [11]

Mammals

Apatemyidae
GenusSpeciesLocationStratigraphic positionMaterialNoteImages
ChardinyusC. sp.An apatotheria.
HeterohyusH. (Chardinyus) nanusAn apatemyid.
H. (Gervaisyus) pygmaeus
GervaisyusG. sp.
Artiodactyls
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
BachitheriumB. guirounetensis
B. lavocati
CryptomeryxC. gaudryi[12]
DichobuneD. sigei
DichodonD. vidalenci
IberomeryxI. matsoui
MosaicomeryxM. quercyi[13]
ParoxacronP. bergeri[14]
PlesiomeryxP. cadurcensis
ProdremotheriumP. elongatum
PseudamphimeryxP. salesmei
RobiacinaR. lavergnensis
R. quercyi
TapirulusTapirulus perrierensis
Carnivora
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
AmphicynodonA. typicus[15]
CephalogaleC. sp.[16]
CynodyctisC. lacustris neboulensis
DinailurictisD. bonali[17] [18]
Eofelis E. edwardsii[19]
E. giganteus[20]
cf. E. sp.[21]
EusmilusE. bidentatus[22]
MustelictisM. cf. major[23]
M. aff. olivieri
NimravusN. intermedius
PachycynodonP. amphictina[24]
P. crassirostris[25]
P. cf. dubius
P. cf. filholi[26]
PalaeogaleP. sectoria
PeignictisP. pseudamphictis[27]
QuercylurusQ. major
WangictisW. tedfordi[28]
Chiroptera
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Hipposideros PseudorhinolophusH. P. sehlosseri
H. P. trassounius
H. P. zbrjdi
LeuconoeL. lavocati
PalaeophyllophoraP. oltina
P. quercyi
StehliniaS. bonisi
S. minor
VaylatsiaV. garouillasensis
V. gerscheli
V. gracilis
V. lapradensis
Creodonta
GenusSpeciesLocationStratigraphic positionMaterialImages
ParacynohyaenodonP. magnus
ParapterodonP. lostangensis
Lipotyphla
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
AmphidozotheriumA. cayluxi
DarbonetusD. aubrelongensis
D. tuberi
MyxomygaleM. antiqua[31]
SaturniniaS. beata
S. pelissiei
Marsupials
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
AmphiperatheriumA. bourdellense
A. lamandini
PeratheriumP. bretouense
P. cayluxi
P. lavergnense
P. perrierense
Rodents
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
ArchaeomysA. intermedius
A. quercyi
BernardiaB. marandati
BlainvillimysB. gemellus
B. gousnatensis
B. langei[32]
B. rotundidens[33]
ElfomysE. medius
EomysE. gigas
E. minus
E. quercyi
EucricetodonE. atavus
E. quercyi
GliravusG. garouillensis
G. itardiensis
IssiodoromysI. limognensis
I. pauffiensis
PalaeosciurusP. goti
ParadelomysParadelomys spelaeus
PatriotheridcmysP. altus
P. altus neboulensis
P. sudrei
PseudoltinomysP. gaillardi
P. major
P. phosphoricus
SciuromysS. cayluxi[34]
S. rigali
TarnomysT. quercynus
TheridomysT. ludensis

Birds

GenusSpeciesLocationStratigraphic positionMaterialImages
AmeghinornisA. sp.
HorusornisH. vianeyliaudae
IdiornisI. itardiensis
ItardiornisI. hessae
LeptogangaL. sp.
NecrobyasN. minimus
NocturnavisN. sp.
PalaeoglauxP. perrierensis
PalaeotodusP. escampsiensis
P. itardiensis
PaleseyvusP. escampensis
PrimocoliusP. sigei
P. minor
QuercymegapodiusQ. brodkorbi
QuercypsittaQ. ivani
Q. sudrei
RecurvirostraR. sanctaeneboulae
SylphornisS. bretouensis
VentivorusV. ragei
Caprimulgiformes
GenusSpeciesLocationStratigraphic positionMaterialImages
EuronyctibiusE. kurochkini[35]
QuercypodargusQ. olsoni

Reptiles

Crocodiles
Lizards
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Ayalasaurus A. tenuis[36]
Brevisaurus B. smithi
CadurciguanaC. hoffstetteri
CadurcogekkoC. piveteaui
DracaenosaurusD. croizeti
EurhelodermaE. gallicum
GeiseltaliellusG. lamandini
MediolacertaM. roceki
NecrosaurusN. cayluxi
N. eucarinatus
OmoiotyphlopsO. priscus
ParaplacosauriopsP. quercyi
PlacosaurusP. rugosus
P. sp.
PlesiolacertaP. lydekkeri
Pseudeumeces P. cadurcensis
PseudolacertaP. mucronata
P. quercyini
QuercycertaQ. maxima
QuercygamaQ. galliae
UromastyxU. europaeus
Snakes
Turtles

Amphibians

Frogs
Salamanders

Insects

Flora

References

Bibliography

Map reports
Paleontology

Notes and References

  1. http://www.fossilworks.org/cgi-bin/bridge.pl?action=displayStrata&geological_group=&formation=Quercy%20Phosphorites&group_formation_member=Quercy%20Phosphorites Quercy Phosphorites Formation
  2. http://www.fossilworks.org/cgi-bin/bridge.pl?action=displayStrata&geological_group=&formation=Phosphorites%20du%20Quercy&group_formation_member=Phosphorites%20du%20Quercy Phosphorites du Quercy Formation
  3. Legendre et al., 1997, p.331
  4. Legendre et al., 1997, p.332
  5. Astruc & Pellissié, 1988, p.8
  6. Legendre et al., 1997, p.333
  7. Tissier et al., 2017, p.6
  8. Vasilyan, 2018, p.19
  9. Van de Kamp et al., 2018, p.12
  10. Legendre et al., 1997, p.334
  11. Legendre et al., 1997, p.335
  12. Sudre, 1984
  13. Mennecart & Métais, 2015
  14. Blondel, 2005
  15. Bonis et al., 2019, p.603
  16. Bonis et al., 2019, p.612
  17. Peigné, 2003
  18. Bonis et al., 2019, p.616
  19. Peigné & Brunet, 2001
  20. Peigné, 2000
  21. Peigné, 2001
  22. Bonis et al., 2019, p.618
  23. Bonis et al., 2019, p.614
  24. Bonis et al., 2019, p.610
  25. Bonis et al., 2019, p.604
  26. Bonis et al., 2019, p.608
  27. Bonis et al., 2019, p.615
  28. Bonis et al., 2019, p.611
  29. Hooker, 2018, p.236
  30. Lavrov, 2007
  31. Hugueney & Maridet, 2017
  32. Ginot et al., 2016, p.7
  33. Hartenberger & Vianey-Liaud, 1978
  34. Vianey-Liaud & Schmid, 2009
  35. Mourer-Chauviré, 1989
  36. Augé, 2005
  37. Rage, 1988
  38. Broin, 1977
  39. Rage, 2006
  40. Laloy et al., 2013
  41. Tissier et al., 2016
  42. Schmied et al., 2013, p.145
  43. Van de Kamp et al., 2018, p.4
  44. Van de Kamp et al., 2018, p.2
  45. De Franceschi et al., 2006, p.99
  46. De Franceschi et al., 2006, p.100
  47. De Franceschi et al., 2006, p.101