1) Cretaceous ammonite
Found on
https://www.crosswordclues.com/clue/heteroceras
Heteroceras is a Lower Cretaceous heteromorph ammonite belonging to the ancyloceratacian family, Heteroceratidae, characterized by a helically coiled juvenile shell at the apex followed by slightly curved adult shaft, with a J-shaped section at the end of it. The shell is ribbed; ribs are concave and oblique on the helix, straight and transverse o...
Found on
http://en.wikipedia.org/wiki/Heteroceras
No exact match found.
