Berriasella jacobi

Berriasella jacobi
Temporal range:
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Family: Neocomitidae
Genus: Berriasella
Species:
B. jacobi
Binomial name
Berriasella jacobi
Mazenot 1939

Berriasella jacobi is an extinct species of ammonite from the late Jurassic and early Cretaceous.[1] Because of its unique stratigraphic position, it is used as an index fossil to determine the boundary of the Cretaceous and Jurassic periods. The Berriasella jacobi zone defines the substage of the Lower Berriasian, the Berriasian being the lowest stage of the Cretaceous.[2] However, due to the species limited geographic distribution, several other candidates that have been nominated, including Calpionella alpina.

  1. ^ "Mindat.org". www.mindat.org. Retrieved 2022-11-11.
  2. ^ https://biblio.naturalsciences.be/rbins-publications/bulletin-of-the-royal-belgian-institute-of-natural-sciences-earth-sciences/66-sup-1996/irscnb_p4087_00da07p_66-sup_bulletin-1-red.pdf