Mantelliceras mantelli Zone

Base: Base of the zone is mostly coincident with the base of the Chalk Group, except where earliest Cenomanian deposits comprise glauconitic sandstones (eg. locally in South-east Devon), where it is within the highest part of the Upper Greensand Formation.

Top: The top of the zone is immediately below the first appearance of Mantelliceras dixoni (Gale, 1995).

Range of Index species: Common in nominate zone, rare in overlying M. dixoni Zone (Wright & Kennedy, 1984).

Key Fauna:

Porifera:	Stauronema carteri
Brachiopoda:	Tropeothyris? carteri
Bivalvia:	Aucellina spp.
	Inoceramus anglicus
	I. crippsi (locally abundant)
Ammonoidea:	Hyphoplites spp.
	Hypoturrilites gravesianus
	Mantelliceras spp. (except M. dixoni)
	Mariella spp.
	Neostlingoceras carcitanense
	Schloenbachia spp. (locally abundant)
	Sharpeiceras spp.

Faunal abundance & preservation: Typically rich and phosphatised fauna near base of zone.

Bio-markers: (see under subzones)

Subzones: Mantelliceras saxbii

Sharpeiceras schlueteri

Neostlingoceras carcitanense

Age: Early Cenomanian