Late Cretaceous (Campanian)
Belo Tsiribihina, near Tulear, Madagascar
82mm heteromorph.

Ammonite, Heteromorph. Cephalopod.

Nostoceras is a genus of heteromorph ammonite known from the Late Cretaceous of all over the world (Alaska, California, British Columbia, Arkansas, Texas, Mexico, Columbia, Angola, Madagascar, New Zealand, and Japan).  It is an especially in-demand ammonite as it is rare in near-complete condition.