- ancestor-descendant relationships, this is not the case for
nautiloids. Instead,
nautiloids are a
paraphyletic grade of
various early-diverging cephalopod...
- found. The
septal curvature in
nautiloids and
ammonoids also
differ in that the
septa curves towards the
opening in
nautiloids, and away from the opening...
- genus' use as a
wastebasket taxon for
numerous species of conical-s****ed
nautiloids throughout the
Paleozoic and Tri****ic.
Since this work was
carried out...
-
became dominant during the
Ordovician period,
represented by
primitive nautiloids. The
class now
contains two, only
distantly related,
extant subclasses:...
-
genera and
families of
nautiloids developed or
retained this form of s****. An orthocone, loosely, may be
thought of as a
nautiloid s****,
albeit somewhat...
-
these claims are problematic. The
overwhelming majority of
endocerids and
nautiloids in
general are much smaller,
usually less than a
meter long when fully...
- or
absence of deposits, are
important in
classification of
nautiloids. In some
nautiloids, such as the Orthoceratidae, the
septa tend to be
widely spaced...
- is
grouped within the
class Cephalopoda with squids, cuttlefish, and
nautiloids. Like
other cephalopods, an
octopus is
bilaterally symmetric with two...
- Coleoidea,
diverged from the
nautiloids long ago and the
nautilus has
remained relatively unchanged since.
Nautiloids were much more
extensive and varied...
- be the
upper surface. All
cephalopods with
external s****
except the
nautiloids became extinct by the end of the
Cretaceous period 65 million
years ago...
