- hypothetical.
Polydesmia was once
thought to be the
ancestral form of the
actinocerids, and was
derived from the
ellesmeroceriid Bathmoceras. However, it turned...
-
million years ago
during the Carboniferous.
Although they
resemble earlier actinocerids they are now
thought to
belong to the
Pseudorthocerida Rayonnoceras is...
-
nautiloid cephalopods, is
prevalent among the ellesmerocerids, endocerids,
actinocerids, orthoceratoids, and bactritids.
Orthocones existed from the Late Cambrian...
- Polydesmia, once
thought to have been the
ancestral actinocerid.
Since then
revision of
actinocerid phylogeny and of
Ordovician stratigraphy in east Asia...
-
Nybyoceras is an
actinocerid genus ****igned to the
Armenoceratidae and
similar to
Armenoceras except for
having a
siphuncle close to the
ventral side...
- ray Gr**** ἀκτίς, ἀκτῖνος (aktís, aktînos) actinic, actinism, actinium,
actinocerid, actinodrome, actinoid, actinomere, actinometer, actinomorphic, actinomyces...
-
called a perispatium.
Although Carbactinoceras had been
considered an
actinocerid according to the
American Teatise Part K, 1964,
based on the internal...
-
Paractinoceras is a
genus of long, straight, and
slender actinocerid nautiloid with
siphuncular segments in the
early stages like
those of Actinoceras...
- ray Gr**** ἀκτίς, ἀκτῖνος (aktís, aktînos) actinic, actinism, actinium,
actinocerid, actinodrome, actinoid, actinomere, actinometer, actinomorphic, actinomyces...
-
narrow siphuncle that is less
common for
actinocerids. Niko,
Shuji 1998.
Kobayashiceras gifuense, a new
actinocerid cephalopod from the
Lower Devonian of...
