- 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...
-
early actinocerids defined by
Shimazu and
Obata in 1938 for
actinocerids with
thick connecting rings and a
complex irregular canal system.
Actinocerids are...
- The
Actinoceriatidae are a
family of
actinocerids named by
Saemann in 1853 for
those that grew to have
large s**** with
blunt apices and
large siphuncles...
- Resources,
Socorro NM.
Flower R.H. 1968, The
First Great Expansion of the
Actinocerids. Part I
Memoir 19, New
Mexico Bureau of
Mines and
Mineral Resources,...
-
problems with the
actinocerid hypothesis.
Carbactinocerids such as
Carbactinoceras appear much
later than the last
definite actinocerids,
leaving a large...
-
nautiloid cephalopods of the
Wutinoceratidae family. It
exhibits orthoconic actinocerids with
ventral siphuncles composed of
broadly expanded segments. Wutinoceras...
- ray Gr**** ἀκτίς, ἀκτῖνος (aktís, aktînos) actinic, actinism, actinium,
actinocerid, actinodrome, actinoid, actinomere, actinometer, actinomorphic, Actinomyces...
-
vertical orientation than the well-ballasted bottom-dwellers such as the
actinocerids and endocerids. The
ventral siphuncle of the
Bactritida would have facilitated...
