See text Panopea is a genus of large marine bivalve molluscs or clams in the family Hiatellidae.

[1] There are 10 described species in Panopea.

[1] Many of them are known under the common name "geoduck".

Extinct species within this genus include:[4] The fossil record of the genus dates back to the Cretaceous (and maybe the Triassic) (age range: 242.0 to 0.012 million years ago).

These fossils have been found all over the world.