Marnes de Dives

The Marnes de Dives is a geological formation in Normandy, France. It dates back to the upper part of the Callovian stage of the Middle Jurassic.^[1] And is partially equivalent to the Oxford Clay in England. It predominantly consists of ooidal marl, rich in pyrite and lignite, interbedded with thin limestone horizons.^[2] It is best exposed at the base of the Falaises des Vaches Noires (Cliffs of Black Cows) as well as the foreshore at low tide. It is known for its fossils, notably those of ammonites, marine crocodiles and fragmentary remains of dinosaurs, mostly theropods.

Panorama of the Falaises des Vaches Noires

Marnes de Dives
Stratigraphic range: Late Callovian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Falaises des Vaches Noires
Type	Geological formation
Underlies	Marnes de Villers
Thickness	8–10 metres (30–30 ft)
Lithology
Primary	Marl
Other	Limestone
Location
Region	Normandy
Country	France
Extent	Paris Basin
Type section
Named for	Dives-sur-Mer

Vertebrate fauna

Dinosaurs

Dinosaurs of the Marnes de Dives
Taxa	Species	Presence	Description	Images
Piveteausaurus[1]	P. divesensis	Vaches Noires	Braincase.[3]
Streptospondylus	S. altdorfensis	Vaches Noires[4]	Megalosaurid dinosaur. Originally a chimera of dinosaur and marine crocodile material. redefined to solely refer to the syntype dinosaur material consisting of "several vertebrae series, single vertebrae, a partial left pubis and limb elements". May be from the overlying Marnes de Villers, but the Marnes de Dives is much more productive and was better exposed when it was collected in the 18th century.
Sauropoda	Indeterminate	Vaches Noires	Remains consist of a single vertebra, destroyed in 1944, may be from the overlying Marnes de Villers[5]
Stegosauria	Indeterminate	Vaches Noires	Remains consist of 2 associated vertebra in hard limestone[6]
Theropoda[1]	Indeterminate	Vaches Noires	Multiple taxa represented, including indeterminate megalosaurid material possibly referrable to the two named taxa alongside fragmentary remains of Allosauroids,[7] Including dentary and maxilla fragments. Other theropod remains include an associated braincase and frontal.[8][9] Allosauroid material bears similarities to metriacanthosaurids. Material is of unclear stratigraphic provenance, and may belong to overlying cliff strata.[10]

Crocodyliformes

Crocodyliformes of the Marnes de Dives
Taxa	Species	Presence	Description	Images
Tyrannoneustes[11]	T. lythrodectikos	Vaches Noires	A geosaurine metriorhynchid
Metriorhynchus	M. geoffroyii	Vaches Noires	A metriorhynchine metriorhynchid
Neosteneosaurus	N. edwardsi	Villers-sur-Mer	A machimosaurid thalattosuchian
Proexochokefalos	P. heberti	Villers-sur-Mer	A machimosaurid thalattosuchian
Thalattosuchus[12]	T. superciliosus	Villers-sur-Mer	A metriorhynchine metriorhynchid

Icthyosaurs

Ichthyosaurs of the Marnes de Dives
Taxa	Species	Presence	Description	Images
Ophthalmosaurus	Indeterminate[13]	Vaches Noires	A ophthalmosaurid ichthyosaur

Fish

Fish of the Marnes de Dives[14]
Taxa	Species	Presence	Description	Images
Leedsichthys[15]	L. problematicus	Vaches Noires	A giant pachycormiform fish, may be from overlying Marnes de Villiers
Trachymetopon	Indeterminate		A giant coelacanth
cf. Hypsocormus	Indeterminate		A pachycormid fish
Pycnodontiformes	Indeterminate
Lepidotidae	Indeterminate		A ginglymodian
Ichthyodectiformes	Indeterminate		A stem-group teleost

See also

• List of dinosaur-bearing rock formations