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

Genus	Species	Location	Stratigraphic position	Material	Note	Images
Chardinyus	C. sp.				An apatotheria.
Heterohyus	H. (Chardinyus) nanus				An apatemyid.
	H. (Gervaisyus) pygmaeus
Gervaisyus	G. sp.

Artiodactyls

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bachitherium	B. guirounetensis
	B. lavocati
Cryptomeryx	C. gaudryi^[12]
Dichobune	D. sigei
Dichodon	D. vidalenci
Iberomeryx	I. matsoui
Mosaicomeryx	M. quercyi^[13]
Paroxacron	P. bergeri^[14]
Plesiomeryx	P. cadurcensis
Prodremotherium	P. elongatum
Pseudamphimeryx	P. salesmei
Robiacina	R. lavergnensis
	R. quercyi
Tapirulus	Tapirulus perrierensis

Carnivora

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Amphicynodon	A. typicus^[15]
Cephalogale	C. sp.^[16]
Cynodyctis	C. lacustris neboulensis
Dinailurictis	D. bonali^[17] ^[18]
Eofelis	E. edwardsii^[19]
	E. giganteus^[20]
	cf. E. sp.^[21]
Eusmilus	E. bidentatus^[22]
Mustelictis	M. cf. major^[23]
	M. aff. olivieri
Nimravus	N. intermedius
Pachycynodon	P. amphictina^[24]
	P. crassirostris^[25]
	P. cf. dubius
	P. cf. filholi^[26]
Palaeogale	P. sectoria
Peignictis	P. pseudamphictis^[27]
Quercylurus	Q. major
Wangictis	W. tedfordi^[28]

Chiroptera

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Hipposideros Pseudorhinolophus	H. P. sehlosseri
	H. P. trassounius
	H. P. zbrjdi
Leuconoe	L. lavocati
Palaeophyllophora	P. oltina
	P. quercyi
Stehlinia	S. bonisi
	S. minor
Vaylatsia	V. garouillasensis
	V. gerscheli
	V. gracilis
	V. lapradensis

Creodonta

Genus	Species	Location	Stratigraphic position	Material	Images
Paracynohyaenodon	P. magnus
Parapterodon	P. lostangensis

Lipotyphla

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Amphidozotherium	A. cayluxi
Darbonetus	D. aubrelongensis
	D. tuberi
Myxomygale	M. antiqua^[31]
Saturninia	S. beata
	S. pelissiei

Marsupials

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Amphiperatherium	A. bourdellense
	A. lamandini
Peratherium	P. bretouense
	P. cayluxi
	P. lavergnense
	P. perrierense

Rodents

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Archaeomys	A. intermedius
	A. quercyi
Bernardia	B. marandati
Blainvillimys	B. gemellus
	B. gousnatensis
	B. langei^[32]
	B. rotundidens^[33]
Elfomys	E. medius
Eomys	E. gigas
	E. minus
	E. quercyi
Eucricetodon	E. atavus
	E. quercyi
Gliravus	G. garouillensis
	G. itardiensis
Issiodoromys	I. limognensis
	I. pauffiensis
Palaeosciurus	P. goti
Paradelomys	Paradelomys spelaeus
Patriotheridcmys	P. altus
	P. altus neboulensis
	P. sudrei
Pseudoltinomys	P. gaillardi
	P. major
	P. phosphoricus
Sciuromys	S. cayluxi^[34]
	S. rigali
Tarnomys	T. quercynus
Theridomys	T. ludensis

Birds

Genus	Species	Location	Stratigraphic position	Material	Images
Ameghinornis	A. sp.
Horusornis	H. vianeyliaudae
Idiornis	I. itardiensis
Itardiornis	I. hessae
Leptoganga	L. sp.
Necrobyas	N. minimus
Nocturnavis	N. sp.
Palaeoglaux	P. perrierensis
Palaeotodus	P. escampsiensis
	P. itardiensis
Paleseyvus	P. escampensis
Primocolius	P. sigei
	P. minor
Quercymegapodius	Q. brodkorbi
Quercypsitta	Q. ivani
	Q. sudrei
Recurvirostra	R. sanctaeneboulae
Sylphornis	S. bretouensis
Ventivorus	V. ragei

Caprimulgiformes

Genus	Species	Location	Stratigraphic position	Material	Images
Euronyctibius	E. kurochkini^[35]
Quercypodargus	Q. olsoni

Reptiles

Crocodiles

Lizards

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Ayalasaurus	A. tenuis^[36]
Brevisaurus	B. smithi
Cadurciguana	C. hoffstetteri
Cadurcogekko	C. piveteaui
Dracaenosaurus	D. croizeti
Eurheloderma	E. gallicum
Geiseltaliellus	G. lamandini
Mediolacerta	M. roceki
Necrosaurus	N. cayluxi
	N. eucarinatus
Omoiotyphlops	O. priscus
Paraplacosauriops	P. quercyi
Placosaurus	P. rugosus
	P. sp.
Plesiolacerta	P. lydekkeri
Pseudeumeces	P. cadurcensis
Pseudolacerta	P. mucronata
	P. quercyini
Quercycerta	Q. maxima
Quercygama	Q. galliae
Uromastyx	U. europaeus

Snakes

• Cadurcoboa insolita^[10]
• Coluber cadurci^[10]
• Dunnophis cadurcensis^[10]
• Eoanilius europae^[10]
• Natrix mlynarskii^{[10] [37]}
• Palaeopython cadurcensis
• P. filholi
• P. neglectus
• Paleryx cayluxi
• Platyspondylia lepta^[10]
• Plesiotortrix edwardsi

Turtles

• Ptychogaster cayluxensis^[38]
• Testudo phosphoritarum
• Testudinidae indet.^[38]

Amphibians

Frogs

• Bufo serratus^[39]
• T. gezei^[40]
• Thaumastosaurus bottii^[39]

Salamanders

• Heteroclitotriton zitteli^[39]
• Megalotriton filholi^[39]
• M. portisi^[39]
• Phosphotriton sigei^[41]

Insects

• Coptera anka
• Onthophilus intermedius^[42]
• Palaeortona quercyensis^[43]
• Xenomorphia handschini^[43]
• X. resurrecta^[44]
• Blattodea^[42]
• Coleoptera^[42]
• Diptera^[42]
• Ensifera^[42]
• Hymenoptera^[42]
• Lepidoptera^[42]
• Myriapoda^[42]

Flora

• Palmocaulon sp.^[45]
• Anacardiaceae indet.^[46]
• Caryophyllales indet.
• Malvaceae indet.^[47]
• Menispermacae indet.^[47]
• Sapotaceae indet.^[47]
• Ulmaceae indet.^[47]
• Vitaceae indet.^[46]

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