-
Silurian member of the
Acleistoceratidae or
perhaps even in some
Ordovician oncoceratid through an
unknown Silurian genus. Sweet, W.C. 1964; Nautiloidea-Oncocerida;...
- America,
except for the
details of the siphuncle.
Similar too are the
oncoceratid Diagenoceras and Dunleithoceras,
among others, from the
latter part of...
-
Silurian of
central Europe.
Perimecoceras is
similar in
general form to the
oncoceratid genus Oonoceras from
which it may have been derived, but
differs in having...
-
Lower Devonian Ankyloceras and
earlier Middle and/or
Upper Ordovician oncoceratids such as
Diagenoceras and Richardsonoceras.
Osbornoceras and
similar oncocerids...
-
through some form like B****leroceras or
Lawrenceoceras to
directly to the
Oncoceratid genus Richardsonoceras. The B****leroceratidae was
named by
Ulrich et...
- segments.
Paroocerina (K288),
named by
Zhurevleva in 1961, is a
slender oncoceratid from the
Middle and
Upper Silurian of
eastern Europe and ex-USSR (Russia)...
- from the Gracilocertidae.(Flower 1950, 1976) Some
Middle Ordovician oncoceratids such as
Richardsonoceras and
Oonoceras are, however,
externally more...
