Cenomanian Stage

What happened during this time?

Flora

• Angiosperms dramatically increase in the species around 100 Ma

  • Laurales found in the fossil record

• Kelp forests may appear at this time (Looy 2014), although direct evidence indicates a Miocene origin

• Earliest evidence of parental care in insects (Wang et al. 2015)

• Oldest evidence of grasses from 100–97 Ma

  • Titanosaurs coprolites indicate at least 5 distinct grass taxa from phytoliths 

Fauna

• At the end of the Cenomanian, an anoxic event took place, called the "Bonarelli Event" that is associated with a minor extinction event for marine species.

• Oldest evidence of flower pollination from a flower beetle with pollen on its legs discovered preserved in amber (Bao et al. 2019)

  • The early diversifications of angiosperms and their insect pollinators were largely decoupled until the end of the Cretaceous (Asar et al. 2020)

• Sirenobethylus charybdis, a parasitic wasp exhibiting mimicry, had an abdomen made up of three flaps, which could open into a flower-shaped structure

  • • It is hypothesized that the wasp could have laid in wait, luring potential host insects with its open trap, then snapped it shut around them. 

    • The wasp would sting and paralyze the host temporarily, allowing the ovipositor to get to work injecting eggs into the hapless victim.

• Evidence from oyster shells found in Western North America indicates temperatures were as warm as today's tropics (Jones et al. 2022)