Angeac-Charente_bonebed Knowpia

Angeac-Charente bonebed
Angeac-Charente bonebed
Stratigraphic range: Berriasian PreꞒ Ꞓ O S D C P T J K Pg N
	The Angeac-Charente bonebed in 2011.
Type	Bed
Underlies	Unconformity with Pleistocene deposits
Thickness	2 metres
Lithology
Primary	Clay
Location
Extent	Aquitaine Basin

The Angeac-Charente bonebed is a fossil deposit located near Angeac-Charente in western France. It dates to the Berriasian stage of the Early Cretaceous, and is coeval with the Purbeck Group of Southern England. It has amongst the most diverse assemblages of earliest Cretaceous vertebrates known from Europe.

History of discovery edit

Dinosaur bones were first found at the site in 2008. The fossils were exposed during quarrying for overlying Pleistocene aged sand and gravel. After more bones were discovered in 2010, a team was set up composed of people from Musée d’Angoulême, Rennes University and the Muséum national d’Histoire naturelle to excavate the site. Due the promising finds, since 2011 excavations have been conducted at the site annually.^[1]

Geology and Paleoenvironment edit

The site was previously considered Hauterivian-Barremian in age,^[2] but is now considered likely middle-late Berriasian in age. The paleoenvironment is considered to have been a freshwater floodplain, dominated by cheirolepidacean conifers, with a tropical or subtropical climate. The lithology of the site is predominantly clay.^[1]

Paleobiota edit

Fish edit

Fish of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Parvodus	P. celsucuspus			Teeth	Hybodont shark
Cf. Micropycnodon	Indeterminate			Teeth	Mesturid pycnodontiform fish
Pycnodontidae	Indeterminate			Teeth
Ginglymodi	Indeterminate			Teeth and ganoid scales
Amiiformes	Indeterminate			"teeth, jaw remains and vertebrae"
Ionoscopiformes	Indeterminate			Teeth

Amphibians edit

Amphibians of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Albanerpetontidae	Indeterminate			"dentaries, premaxillae, maxillae, vertebrae and forelimb bones"
Anura	Indeterminate			Fragmentary bones
?Caudata	Indeterminate			Vertebra	An assignment to Squamata cannot be excluded

Turtles edit

Turtles of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Pleurosternon	P. bullockii			At least 12 individuals as well as one complete shell	Pleurosternid paracryptodire
Hylaeochelys	H. belli?			"many isolated plates and one incomplete specimen discovered in 2018, consisting of parts of the plastron, some peripherals and both humeri"	Thalassochelydian, represented by juveniles
Helochelydridae	Indeterminate			"incomplete isolated shell elements covered by typical tubercles, pustules and crests"

Lepidosauria edit

Lepidosaurs of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
cf. Opisthias	Indeterminate			"posterior dentary fragment bearing two preserved acrodont teeth in addition to seven broken teeth"	Sphenodontian
Paramacellodus	Indeterminate			"jaw fragment bearing two closely spaced teeth"	Paramacellodid lizard

Choristodera edit

Choristoderes of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
cf. Cteniogenys	Indeterminate			"A characteristic robust vertebra, as well as a smaller vertebra that probably belongs to a juvenile individual"

Pterosaurs edit

Pterosaurs of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Pterosauria	Indeterminate			Teeth of three distinct morphotypes, at least some of which belong to pterodactyloids

Crocodyliforms edit

Crocodyliforms of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Goniopholis	Indeterminate			"skull, mandibles, vertebrae, limb, girdle bones and osteoderms" belonging to a single individual, along with other isolated remains	Goniopholidid
Pholidosaurus				Teeth	Pholidosaurid
Theriosuchus				Teeth	Atoposaurid
Bernissartiidae				Teeth

Dinosaurs edit

Ornithischians edit

Ornithischians of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
cf. Echinodon	Indeterminate			Two premaxillary teeth	Heterodontosaurid
Dacentrurus sensu lato				84 skeletal elements, including vertebrae, ribs, several phalanges and elements of the braincase, likely belonging to a single individual	Dacentrurine stegosaur
Hypsilophodontidae				Premaxillary tooth, maxillary tooth and dentary tooth	Similar to Hypsilophodon
Camptosauridae				Dentary tooth, femur
Ankylosauria				Tooth and osteoderm

Sauropods edit

Sauropods of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Turiasauria (="Francoposeidon")	Indeterminate			"braincase, some skull bones, teeth, cervical, dorsal and caudal vertebrae, chevrons, pelvic girdle and all the limb bones" alongside isolated teeth, belonging to at least 7 individuals	All belongs to a single taxon
Macronaria	Indeterminate			Two teeth	Probably closely related to Camarasaurus

Theropods edit

Theropods of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
cf. Nuthetes	Indeterminate			Several teeth	Dromaeosaurid
Ornithomimosauria	Undescribed			Isolated remains of at least 70 individuals representing almost all of the skeleton	Most abundant fossil at the site
?Megalosauridae	Indeterminate			large (> 3 cm) blade–like teeth	Likely assignable to a single taxon, possibly assignable to other groups of basal tetanurans
Tyrannosauroidea	Indeterminate			8 teeth
Archaeopterygidae	Indeterminate			5 teeth

Mammals edit

Mammals of the Angeac bed
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Thereuodon	T. cf. taraktes			Isolated tooth crown	Symmetrodont
?Gobiconodon	Indeterminate			Isolated tooth crown	Gobiconodontid
?Triconodon	Indeterminate			Almost complete tooth	Triconodontid
Sunnyodon	Indeterminate			Premolar	?Paulchoffatiid Multituberculate
Spalacotherium	S. evansae			Three teeth	Spalacotheriid
Peramus	Indeterminate				Peramurid
Dryolestidae	Indeterminate			two fragmentary molars	Closely related to Guimarotodus and Phascolestes
Pinheirodontidae	Indeterminate			Numerous teeth	Multituberculate

References edit

^ ^a ^b Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.. Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary. Geodiversitas, Museum National d’Histoire Naturelle Paris, In press. ffhal-03264773f
^ Néraudeau, D.; Allain, R.; Ballèvre, M.; Batten, D.J.; Buffetaut, E.; Colin, J.P.; Dabard, M.P.; Daviero-Gomez, V.; El Albani, A.; Gomez, B.; Grosheny, D. (October 2012). "The Hauterivian–Barremian lignitic bone bed of Angeac (Charente, south-west France): stratigraphical, palaeobiological and palaeogeographical implications". Cretaceous Research. 37: 1–14. doi:10.1016/j.cretres.2012.01.006.

[:0-1] Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.. Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary. Geodiversitas, Museum National d’Histoire Naturelle Paris, In press. ffhal-03264773f

[2] Néraudeau, D.; Allain, R.; Ballèvre, M.; Batten, D.J.; Buffetaut, E.; Colin, J.P.; Dabard, M.P.; Daviero-Gomez, V.; El Albani, A.; Gomez, B.; Grosheny, D. (October 2012). "The Hauterivian–Barremian lignitic bone bed of Angeac (Charente, south-west France): stratigraphical, palaeobiological and palaeogeographical implications". Cretaceous Research. 37: 1–14. doi:10.1016/j.cretres.2012.01.006.

[1]

[2]

Angeac-Charente bonebed
Stratigraphic range: Berriasian PreꞒ Ꞓ O S D C P T J K Pg N
The Angeac-Charente bonebed in 2011.
Type	Bed
Underlies	Unconformity with Pleistocene deposits
Thickness	2 metres
Lithology
Primary	Clay
Location
Extent	Aquitaine Basin

Summary