Late Cretaceous (Campanian)
Belo Tsiribihina, near Tulear, Madagascar
87mm heteromorph
Ammonite, Heteromorph. Cephalopod.

Nostoceras is a genus of heteromorph ammonite known from Late Cretaceous sites over a wide range from California to British Columbia to Texas to Columbia to Angola to Madagascar to New Zealand to Japan though it is not commonly found anywhere.  Specimens appear on the market only occasionally.