Angeac-Charente bonebed

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Angeac-Charente bonebed
Stratigraphic range: Berriasian
AngeacDino3.jpg
The Angeac-Charente bonebed in 2011.
TypeBed
Underlies Unconformity with Pleistocene deposits
Thickness2 metres
Lithology
Primary Clay
Location
Extent Aquitaine Basin

The Angeac-Charentebonebed 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.

Contents

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

Tables follow Allain et al. (2022) [1]

Fish

Fish of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
Parvodus P. celsucuspusTeeth Hybodont shark
Cf. Micropycnodon IndeterminateTeeth Mesturid pycnodontiform fish
Pycnodontidae IndeterminateTeeth
Ginglymodi IndeterminateTeeth and ganoid scales
Amiiformes Indeterminate"teeth, jaw remains and vertebrae"
Ionoscopiformes IndeterminateTeeth

Amphibians

Amphibians of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
Albanerpetontidae Indeterminate"dentaries, premaxillae, maxillae, vertebrae and forelimb bones"
Anura IndeterminateFragmentary bones
?Caudata IndeterminateVertebraAn assignment to Squamata cannot be excluded

Turtles

Turtles of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
Pleurosternon P. bullockiiAt 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
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
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
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
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
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
Pterosauria IndeterminateTeeth of three distinct morphotypes, at least some of which belong to pterodactyloids

Crocodyliforms

Crocodyliforms of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
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

Ornithischians

Ornithischians of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
cf. Echinodon IndeterminateTwo premaxillary teeth Heterodontosaurid
Dacentrurus sensu lato84 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 toothSimilar to Hypsilophodon
Camptosauridae Dentary tooth, femur
Ankylosauria Tooth and osteoderm

Sauropods

Sauropods of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
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 individualsAll belongs to a single taxon
Dinosaure - La vie en grand - Angeac - Sauropoda - Femur - 009.jpg
Macronaria IndeterminateTwo teethProbably closely related to Camarasaurus

Theropods

Theropods of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
cf. Nuthetes IndeterminateSeveral teeth Dromaeosaurid
Ornithomimosauria UndescribedIsolated remains of at least 70 individuals representing almost all of the skeletonMost abundant fossil at the site, [1] some authors have argued for a ceratosaur identity [3]
?Megalosauridae Indeterminatelarge (> 3 cm) blade–like teethLikely assignable to a single taxon, possibly assignable to other groups of basal tetanurans
Tyrannosauroidea Indeterminate8 teeth
Archaeopterygidae Indeterminate5 teeth

Mammals

Mammals of the Angeac bed
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages
Thereuodon T. cf. taraktesIsolated tooth crown Symmetrodont
? Gobiconodon Indeterminate Gobiconodontid
? Triconodon Almost complete tooth Triconodontid
Sunnyodon IndeterminatePremolar?Paulchoffatiid Multituberculate
Spalacotherium S. evansaeThree teeth Spalacotheriid
Peramus Indeterminate Peramurid
Dryolestidae Indeterminatetwo fragmentary molarsClosely related to Guimarotodus and Phascolestes
Pinheirodontidae IndeterminateNumerous teethMultituberculate

References

  1. 1 2 3 4 Allain, Roman; et al. (2022). "Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary". Geodiversitas. 44 (25): 683–752.
  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.
  3. Cau, Andrea; Paterna, Alessandro (May 2025). "Beyond the Stromer's Riddle: the impact of lumping and splitting hypotheses on the systematics of the giant predatory dinosaurs from northern Africa". Italian Journal of Geosciences. 144 (2): 1–24. doi:10.3301/IJG.2025.10.