''Discoceras'' is an extinct marine
cephalopod
A cephalopod is any member of the molluscan class Cephalopoda ( Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, ...
mollusk, a member of the
Trocholitidae
The Trocholitidae are Tarphycerida with whorls in close contact as with the Tarphyceratidae, but in which the siphuncle, similar in structure, becomes dorsal. The Trocholitidae are derived from the Tarphyceratidae, perhaps from different tarphyce ...
in the
Tarphycerida
The Tarphycerida were the first of the coiled cephalopods, found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian. Some, such as ''Aphetoceras'' and ''Estonioceras'', are loosely coiled and gyroconic; ...
. It is distinct from ''
Discosorus
''Discosorus'', a genus of the Discosorida and member of the family Discosoridae. Not to be confused with ''Discoceras''. ''Discosorus'' consists of rapidly expanding endogastric brevicones, mostly known from isolated siphuncles composed of broad ...
'', It is characterized by closely coiled, gradually expanding
shells with a