Gravesia (ammonite) explained

Gravesia is an extinct genus of ammonite known from the Upper Jurassic (Kimmeridgian-Tithonian stages) of Europe.^{[1] [2]}

Notes and References

1. Scherzinger. Armin. Schweigert. Günter. May 2016. The ammonite genera Gravesia Salfeld and Pseudogravesia Hantzpergue in the Tithonian of S Germany and their correlation value with Western Europe. Proceedings of the Geologists' Association. en. 127. 2. 288–296. 10.1016/j.pgeola.2015.12.010.
2. Book: S.M., Gallois, R.W. Etches. The distribution of the ammonite Gravesia (Salfeld, 1913) in the Kimmeridge Clay Formation (Late Jurassic) in Britain. 2010. Ussher Society. 769109876.