I love painting Ammonites in an impressionist style - in various bright colors and in different mediums - or media (take your pick:)
This one was painted with encaustic pigmented molten waxes onto an Ampersand gessoboard.
As per Wikipedia:
Ammonites are a group of extinct marine animals.
The closest living relative of the Ammonite, is not the modern Nautilus which they somewhat outwardly resemble, but rather the subclass Coleoidea (octopus, squid, and cuttlefish).
The last surviving lines disappeared along with the dinosaurs 65 million years ago.