Muramotoceras was an unusual genus of heteromorphic ammonite.
[2] It was known only from Japan until researchers reported in 2001 that the genus was present in Alaska's Matanuska Formation as well.
[2] Its remains likely date to the middle Turonian (from 89.8 to 93.9 million years ago) in both areas.
[2] Subsequently it was also described from the Santonian Gosau Group (Austria).
This Ammonitida-related article is a stub.