Меловой период

Delanoy G., Baudouin C., Boselli M. & Penagé E. (2016) Ivaldiceras, a new genus of heteromorphic ammonites from the Lower Aptian of southeast France.- Carnets Geol., Madrid, vol. 16, no. 15, p. 369-381.

http://paleopolis.rediris.es/cg/1615/index.html