- with
Actinoceras margaretae, A. aequale, and A.
gradatum the
earliest known,
coming from the
lower Blackriveran Loweville fm of Ottawa.
Actinoceras concavum...
-
nautiloid with
siphuncular segments in the
early stages like
those of
Actinoceras,
becoming narrower in the
later stages of the
chambered phragmocone like...
-
Actinoceras, the main
difference between the two
being that
Kochoceras is
breviconic (short) and has a
narrow stratigraphic range,
while Actinoceras is...
- the
ventral side and is
closely allied with
Actinoceras (Flower 1957)
Lambeoceras is
found with
Actinoceras, Armenoceras, and
Nybyoceras in the Second...
- Actinoceratidae,
Actinoceras, Floweroceras, Kochoceras, Leurorthoceras, Paractinoceras, Saffordoceras, and Troostoceras.
Actinoceras is the
earliest but...
-
estimate based on "the most
complete of the
fragments which represent it".
Actinoceras vaughanianum 1.198 m (estimate) Klug et al. (2015:270) From the Serpukhovian...
-
actinoceratid nautiloids with a
cyrtoconic s****,
otherwise similar to
Actinoceras. The s**** is
slightly endogastric,
curved such that the
under or ventral...
- than 0.2 the s**** diameter.
Saffordoceras is
probably derived from
Actinoceras.
Related contemporary genera include Paractinoceras and Troostoceras...
-
septa are
crowded closely together. In some straight-s****ed
forms like
Actinoceras,
calcium carbonate deposits extend from the
camera (mural deposits) to...
- rise to the
Armenoceratidae and
possibly to the
immediate ancestors of
Actinoceras.
Flower 1976. New
American Wutinoceratidae with
Review of Actinoceroid...
