Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name.
| Cenomanian | |||||||||
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| Chronology | |||||||||
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| Etymology | |||||||||
| Name formality | Formal | ||||||||
| Usage information | |||||||||
| Celestial body | Earth | ||||||||
| Regional usage | Global (ICS) | ||||||||
| Time scale(s) used | ICS Time Scale | ||||||||
| Definition | |||||||||
| Chronological unit | Age | ||||||||
| Stratigraphic unit | Stage | ||||||||
| Time span formality | Formal | ||||||||
| Lower boundary definition | FAD of the Planktonic Foraminifer Rotalipora globotruncanoides | ||||||||
| Lower boundary GSSP | Mont Risoux, Hautes-Alpes, France 44.3925°N 5.5119°E | ||||||||
| Lower GSSP ratified | 2002 | ||||||||
| Upper boundary definition | FAD of the Ammonite Watinoceras devonense | ||||||||
| Upper boundary GSSP | Rock Canyon, Colorado, US 38.2822°N 104.7275°W | ||||||||
| Upper GSSP ratified | September 2003 | ||||||||
As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya.
The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States.
At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for marine species.
Cenomanithrips, an extinct thrips of the Stenurothripidae family, was named after the Cenomanian, the age of the Myanmar amber in which it was discovered.