Aturia angustata
Miocene
Lincoln Creek Formation
Grays Harbor County, Washington USA.

32mm tertiary nautiloid in 69mm concretion

Aturia is a nautiloid genus known from the Paleocene to Miocene of various sites worldwide.

Back in the Ordovician Period, nautiloids ascended to the level of apex predator and survived serious competition from various jawed fish groups during the Devonian.  They escaped mass extinction events all the way into the Cenozoic Era.  They rediversified before going into decline by the Late Miocene.  Today, only a few species survive in the Indo-Paciifc region.