# Sainte-Barbe Clays Formation

The Sainte-Barbe Clays Formation is a geological formation in Belgium. It is found in localised areas of the northern margin of the Mons Basin, alongside the equivalently aged Hautrage and Baudour Clay Formations. It is Upper Barremian-Lower Aptian in age. It predominantly consists of laminated clay, with some lignite. It is well known for the "Iguanodon sinkhole" locality near Bernissart where many specimens of Iguanodon bernissartensis were described by Louis Dollo in the late 19th century.

## Geologic context

The Sainte-Barbe Clays Formation are part of the stratigraphy of the Mons Basin, a Cretaceous-Cenozoic sedimentary basin in western Belgium. The subsidence of the basin floor is caused by the dissolution of anhydrite in the Carboniferous basement. Wealden facies are the oldest units within the basin, and are only found on the northern margin of the basin, being absent from the central and southern parts of the basin. Localised areas of significant subsidence, referred to as "sinkholes" are observed. The Wealden facies are overlain by "mixed siliciclastic–carbonate formations" called Meules dating to the Albian.

## Fossil content
### Tetrapods

Tetrapods of the Sainte-Barbe Clays Formation :
| Genus | Species | Location | Abundance | Notes |
| Anteophthalmosuchus | A. epikrator | Bernissart | "Two ... fully articulated skeletons, one missing the skull and mandible." | Goniopholidid crocodyliform |
| Bernissartia | B. fagesii | Bernissart | IRSNB R46, mostly complete skeleton | Bernissartiid crocodyliform |
| Chitracephalus | C. dumonii | Bernissart | Carapace with preserved limbs | Cryptodiran turtle |
| Iguanodon | I. bernissartensis | Bernissart | Multiple skeletons | Iguanodontian dinosaur |
| Mantellisaurus | M. atherfieldensis | Bernissart | IRSNB 1551, single mostly complete skeleton | Iguanodontian dinosaur, formerly considered holotype of "Dollodon bampingi" |
| Hylaeobatrachus | H. croyii | Bernissart | Slab and counterslab of a complete skeleton | Salamander |
| Peltochelys | P. duchastelii | Bernissart | Shell fragments | Paracryptodire, probable close relative of Compsemys |
| Theropoda | Indeterminate | Bernissart | Phalanx | |

### Fish

Fish of the Sainte-Barbe Clays Formation :
| Genus | Species | Location | Abundance | Notes |
| Aethalionopsis | A. robustus | Bernissart | | Formerly referred to Anaethalion |
| Amiopsis | A. dolloi | Bernissart | | |
| Barbalepis | B. macroptera | Bernissart | | Coccolepid fish, formerly referred to Coccolepis |
| Pleuropholis | P. germinalis | Bernissart | | Pleuropholid fish |
| Callopterus | C. insignis | Bernissart | | Genus is later considered as nomen nudum and Ainia is used for Jurassic species, but validity of this species is not discussed |
| Pattersonella | P. formosa | Bernissart | | Formerly referred to Leptolepis |
| Scheenstia | S. bernissartensis | Bernissart | Multiple specimens | Previously referred to Lepidotes, L. brevifulcratus is a junior synonym. |
| Turbomesodon | T. bernissartensis | Bernissart | Multiple specimens | Previously referred to Mesodon and Macromesodon. |

#### Other fish

* Leptolepis attenuatus
* L. brevis
* Notagogus parvus
* Nybelinoides brevis
* Ophiopsiella dorsalis
* Ophiopsis penicillatus
* Arratiaelops vectensis
* Pholidophorus obesus
* Scheenstia mantelli
* Belonostomus sp.
* Caturus sp.
* Pholidophorus sp.
* Polypsephis sp.
* Typodus sp.

### Insects

The Tettigarctid cicada Hylaeoneura lignei is known from the formation.

### Parasites

* Ascarites gerus
* A. priscus
* Digenites proterus
* Entamoebites antiquus

### Flora

* Alethopteris elegans
* Cladophlebis dunkeri
* Conites minuta
* Laccopteris dunkeri
* Leckenbya valdensis
* Matonidium goepperti
* Onychiopsis mantelli
* Pecopteris conybeari
* P. polymorpha
* Pinites solmsi
* Polypodites mantelli
* Ruffordia goepperti
* Sagenopteris mantelli
* Sphenopteris delicatissima
* S. fittoni
* S. roemeri
* Stellatopollis hughesii
* Weichselia mantelli
* Adiantites sp.
* Equisetites sp.
* Gleichenia sp.
* Gleichenites sp.
* Hausmannia (Protorhipis)
* Lycopodites sp.
* cf. Taeniopteris sp.

### Ichnofossils

* Algites sp.