Nostoceras (Rare)

Rare Nostoceras heteromorph ammonite from Tulear, Madagascar.
 
The name comes from the Greek word 'nostos' meaning return and 'ceras' meaning horn due to the species shell bending back on itself.
 
Heteromorphs are unusual ammonites with shells that are uncurled or almost completely straight instead of the tightly curled shells of most ammonites.
 
386g 10.5 x 6.5cm approx