Angeac-Charente bonebed
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
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
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
Fish
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
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
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
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
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
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
Dinosaurs
Ornithischians
Sauropods
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
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
References
^ 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 .
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