Hesseltal Formation
Stratigraphic range:LateCenomanian-EarlyTuronian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Planerkalk Group
Lithology
Primary	Marl,limestone
Other	Black shale
Location
Country	Germany
Extent	North Rhine-Westphalia Lower Saxony
Type section
Named by	Hiss, Kaplan & Wiese
Year defined	2007

TheHesseltal Formation orBlackcoloured Formation is aLate Cretaceous (lateCenomanian to earlyTuronian) geological formation from northernGermany. It consists of lithifiedmarls andlimestone, with a unique series ofblack shales deposited inanoxic conditions during theCenomanian-Turonian boundary event.^{[1][2][3][4][5][6]}

It provides an important record of the fauna of the proto-North Sea basin. The formation's diversity of fossil fish is thought to be due to a consequence of an expandingoxygen minimum zone that causedmass mortalities among different communities of fish, including both those associated with warm surface waters and those associated with colder waters fromupwelling. The anoxic conditions allowed for detailed preservation of some of these fish, including bony fish with their stomach contents preserved and even a few partial body fossils of cartilaginous fish.^[5][7] Fossilammonites with preserved soft parts are also known.^[8]

The formation's deposition also documents thePlenus Cold Event, an enigmatic, brief but severe cooling event that occurred during the otherwise rapid global warming from the Cenomanian-Turonian boundary event, possibly as a consequence of changing ocean circulation.^[5]

Most fish are documented in Diedrich (2012) and a species list from Amalfitanoet al (2020).^[7][9]

Genus	Species	Location	Material	Notes	Images
Apateodus	A. striatus			Anichthyotringid aulopiform.
Armigatus	A. brevissimus			Anellimmichthyiformclupeomorph.
Anomoeodus	A. angustus			Apycnodont.
	A. muensteri
Aulolepis	A. typus			Actenothrissiform.
Apsopelix	A. anglicus			A crossognathidcrossognathiform.
Bananogmius	B. ornatus			Aplethodidtselfatiiform. Preserved withClupavus in the stomach.
Belonostomus	B. cinctus			Anaspidorhynchid.
Cimolichthys	C. levesiensis			Acimolichthyidaulopiform.
Clupavus	C. maroccanus			A basalostariophysian. The most common fish of the formation.
Cylindracanthus	C. cf.minor		Rostral fragment	A fish of uncertain affinities.
Dercetis (=Leptotrachelus)	D. sp.			Adercetid aulopiform.
?Dixonanogmius	D. sp.[10]			A plethodid.
Elopopsis	E. microdon			Apachyrhizodontid crossognathiform.
Enchodus	E. lewesiensis			Anenchodontid aulopiform.
	E. venator
Hoplopteryx	H. lewesiensis			Atrachichthyiform.
Ichthyodectes	I. sp.			Anichthyodectid.
Ichthyotringa	I. africana			An ichthyotringid aulopiform.
Njoerdichthys	N. dyckerhoffi[11]	Galgenknapp Quarry, Hohne Quarry		A pycnodont.
Osmeroides	O. lewesiensis			Anosmeroididelopiform.
Pachyrhizodus	P.subulidens			A pachyrhizodontid crossognathiform.
	P. sp.
Paranursallia	P. gutturosa			A pycnodont.
Protosphyraena	P. sp.			Abillfish-likepachycormid.
"Pycnodus"	"P."scrobiculatus			A pycnodont.
Rhamphoichthys	R. taxidiotis[10]	DIMAC Quarry		A billfish-likeplethodid.
Rharbichthys	R. ferox			An aulopiform.
Rhynchodercetis	R. sp.			A dercetid aulopiform.
Protostomias	P. maroccanus			Adragonfish-liketeleost.
Tselfatia	T. formosa			A plethodid.
Xiphactinus	X. sp.			An ichthyodectid.

Genus	Species	Location	Material	Notes	Images
Cantioscyllium	C. decipiens			Anurse shark.
Carcharias	C. sp.			Asand shark.
Chiloscyllium	C. greenei			Abamboo shark.
Cretalamna	C. appendiculata			Anotodontid shark.
Cretascyliorhinus	C. aff.destombesi			Ascyliorhinid shark.
Cretodus	C. semiplicatus			Apseudoscapanorhynchid shark.
Cretoxyrhina	C. denticulata			A cretoxyrhinid shark.
	C. mantelli
Diprosopovenator	D. hilperti[5]		Partial body fossils	Apseudoscyliorhinid shark (formerlyParaorthacodus sp.)
?Eostriatolamia	?E. subulata			A sand shark.
Heterodontus	H. caniculatus			Abullhead shark.
	H. polydictyos
Paranomotodon	P. angustidens			Athresher shark.
Protolamna	P. acuta			A pseudoscapanorhynchid shark.
	P. sokolovi
Pseudoscyliorhinus	P. schwarzhansi			A pseudoscyliorhinid shark
Posadaia	P. nolfi			A sand shark.
Pseudospinax	P. pusillus			A bamboo shark.
Ptychodus	P. decurrens		Articulated specimen, teeth	A ptychodontid shark.
	P. mammilaris
Polyacrodus	P. polyptychus			Ahybodontid shark.
Scapanorhynchus	S. raphiodon			Agoblin shark.
Squalicorax	S. falcatus			Acrow shark.
Squatina (Cretascyllium)	S. cranei			Anangelshark.
Squatirhina	S. westfalica			Aray of uncertain affinities.
Turoniabatis	T. ornata			A ray of uncertain affinities.

Genus	Species	Location	Material	Notes	Images
Coniasaurus	C. crassidens[12]	DIMAC quarry	Dentary, teeth	Adolichosaurid squamate
Dolichosaurus	D. longicollis[12]	DIMAC quarry	Dorsal vertebra	A dolichosaurid squamate
Mosasauroidea indet.[12]		DIMAC quarry	Articulated tail	The oldest articulatedmosasaur remains from Europe.

• Geologic formations of Germany
• Shale formations
• Cretaceous Germany
• Cenomanian Stage
• Turonian Stage

• Articles with short description
• Short description matches Wikidata