-
tightly coiled, but
evolute with all
whorls showing. The body
chamber of
tarphycerids is
typically long and tubular, as much as half the
length of the containing...
-
nautiloid genus from the
Middle Ordovician and type for the
Lituitidae (a
tarphycerid family) that in some more
recent taxonomies has been
classified with...
- Trocholites, an
tarphycerid from the
Upper Ordovician of Wisconsin...
-
Rhynchorthoceras is
probably derived from
Ancistroceras by a loss of the
tarphycerid type apex,
although it has been
included with the
orthocerid Sinoceratidae...
-
Aphetoceras is a
genus of
tarphycerid cephalopod within the Estonioceratidae;
loosely coiled without an
impression along the
dorsal margin;
early whorls...
-
Ophioceras is a
genus of
closely coiled tarphycerid nautiloid cephalopods, the sole
representatives of the
family Ophidioceratidae,
characterized by an...
- The
Lituitidae are a
family of
evolved tarphycerids characterized by a long
orthoconic section that
follows a
coiled juvenile portion at the apex, along...
-
Laureloceras is a
genus of the
tarphycerid family Plectoceratidae that
lived during the
Middle Silurian in what is now
North America. The s**** of Laureloceras...
- as
evolutionarily unlikely.
Lituites and the
Lituitidae are
derived tarphycerids and
belong to a
separate evolutionary branch of nautilioids. The number...
- a compressed, annulate,
lituiconic nautiloid included in the
derived Tarphycerid family, Uranoceratidae. The s**** is
gyroconic in the
early stage, becoming...
