-
Planispiral is a
condition in
which a
tubicolous s**** is
coiled in a
single horizontal plane and the
diameter increases away from the axis of coiling...
-
periods is
often possible.
Their fossil s****
usually take the form of
planispirals,
although some
helically spiraled and
nonspiraled forms (known as heteromorphs)...
-
conical tube, the
growth of
which is
coiled into an
overall helical or
planispiral shape, for
reasons of both
strength and compactness. The
number of whorls...
- used to
describe various kinds of
freshwater snails whose s**** are
planispiral,
meaning that the s**** is a flat coil. Such s****
resemble a coil of...
- View of the
spire side of the
planispiral s**** of the
freshwater snail Anisus septemgyratus. The body
whorl is the
outermost complete revolution of the...
- sole
living cephalopods whose bony body
structure is
externalized as a
planispiral s****. The
animal can
withdraw completely into its s**** and
close the...
-
limestones of the
Carboniferous period in Europe, the s**** of
which is
planispirally coiled and can be
mistaken for the s**** of a cephalopod.[citation needed]...
- internal, chambered,
endogastrically coiled s**** in the
shape of an open
planispiral (a flat
spiral wherein the
coils do not
touch each other), and consisting...
-
superfamily Aipocerataceae. For the rest,
nautilids adapted the
standard planispiral s**** form,
although not all were as
tightly coiled as the
modern nautilids...
- It is
known from
northern Europe.
Aegocrioceras is
coiled in an open
planispiral;
whorls are
strongly ribbed and bear
spines on the
outer shoulders (ventro-lateral)...
