-
Plectronocerida is a
primitive order from
which subsequent cephalopod orders are
ultimately derived.
Plectronoceratids are
known from the
Upper Cambrian...
-
ability to float)
would have come later,
followed by
swimming in the
Plectronocerida and
eventually jet
propulsion in more
derived cephalopods. Possible...
-
Plectronoceratoidea contains several exclusively Cambrian cephalopod orders:
Plectronocerida, Protactinocerida, and Yanhecerida.
Under some
classification schemes...
- float)[clarification needed]
would have come later,
followed by
swimming in the
Plectronocerida and
eventually jet
propulsion in more
derived cephalopods. However...
- that are
phylogenetically related. They are: †Plectronoceratoidea = †
Plectronocerida, †Protactinocerida, †Yanhecerida, and †Ellesmerocerida. †Endoceratoidea...
-
superorder Plectonoceratoidea,
which she
defined as
containing the
Plectronocerida,
Ellesmerocerida and two
orders introduced by Chen and
Teichert in...
-
Earliest unambiguous cephalopods:
Plectronocerida: Plectronoceras, Monoplacophora-like form: Knightoconus?
First appearance of long-lasting
lineages Goniatite...
-
Earliest unambiguous cephalopods:
Plectronocerida: Plectronoceras, Monoplacophora-like form: Knightoconus?
First appearance of long-lasting
lineages Goniatite...
-
cephalopod orders. They were very
similar to
members of the
order Plectronocerida in most respects. Like plectronocerids,
their s**** were compressed...
- (mid-Stage 10)
nautiloid cephalopods. They were
similar to the more
diverse Plectronocerida and Ellesmerocerida, with
short s****,
closely spaced septa, and diaphragms...
