- that the
earliest nautiloids had s**** that were
slightly curved. An
orthoconic form
evolved several times among cephalopods, and,
among nautiloid cephalopods...
-
coiled morphologies and
giant straight-s****ed
forms (orthocones). No
orthoconic and only a
handful of
coiled species, the nautiluses,
survive to the present...
- ancestry,
followed by a long,
moderately expanding,
generally straight,
orthoconic adult section with a
subdorsal siphuncle connecting the chambers. The...
- and
related orthoconic nautiloid cephalopods are
often confused with the
superficially similar Baculites and
related Cretaceous orthoconic ammonoids. Both...
-
detected in
cephalopod fossils dating as far back as the Silurian;
these orthoconic individuals bore
concentric stripes,
which are
thought to have served...
- The
Bactritida are a
small order of more or less straight-s****ed (
orthoconic)
cephalopods that
first appeared during the
Emsian stage of the Devonian...
-
nautiloid classification. Flower, R. H. (1955). "Cameral
deposits in
orthoconic nautiloids".
Geological Magazine. 92 (2): 89–103. Bibcode:1955GeoM...92...
- Late Silurian.
Their s**** were
variable in form. Some were
straight (
orthoconic),
others curved (cyrtoconic); some were long (longiconic),
others short...
-
subclass of
nautiloid cephalopods.
Members of this
subclass usually have
orthoconic (straight) to
slightly cyrtoconic (curved) s****, and
central to subcentral...
-
Ordovician to the Devonian. The s**** is
usually long, and may be
straight ("
orthoconic") or
gently curved. In life,
these animals may have been
similar to the...
