- Archiacoceratidae, a
family characterized by compressed, exogastric,
cyrtocones with a large, actinosiphonate,
dorsal siphuncle. The
Paleobiology Database...
-
nautiloid cephalopods from the
Ordovician comprising exogastric longiconic cyrtocones, that is no
longer in
common use. The
Order B****lerocerida was established...
-
generally characteristic of its family, the Paraphragmitidae, an
annulated cyrtocone. In the case of
Calocyrtoceras striated both
transversely and longitudinally...
-
found in mid
Silurian sediments in Europe. The s**** is a
longiconic cyrtocone, like that of
Jovellania or Mixosiphonoceras,
except for
being compressed...
- the Poterioceratidae, a
family of
subcircular to
compressed exogastric cyrtocones without a
hyponomic sinus.
Mecynoceras has a compressed,
gibbous cyrtoconic...
- of Australia. The s**** of
Macrodomoceras is a compressed,
endogastric cyrtocone, i.e.
section higher than wide and
curved with the
ventral side concave...
- of this
genus are
generally slender,
gradually expanding,
exograstric cyrtocones with an
ovoid cross section more
narrowly rounded ventrally than dorsally...
- conch, of
Cyrtocycloceras is a
moderately expanding annulated exogastric cyrtocone, with
curvature like that of a
rocking chair rocker. Annulations, encircling...
-
Oncocerida to
include genera characterized by
longiconic orthocones and
cyrtocones with a
subtriangular to
depressed cross-section in
which the
ventral (siphuncular)...
- of the
order Oncocerida,
Fayettoceras has a s****
which is a
depressed cyrtocone with a
ventral cyrtochoanitic siphuncle of
elongated ovoid segments strongly...
