-
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...
-
geologic time periods.
Their fossil s****
usually take the form of
planispirals,
although some
helically spiraled and
nonspiraled forms (known as heteromorphs)...
-
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]...
-
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...
- snails. The word is also
applied to the
depressed central area on the
planispiral coiled s**** of
Nautilus species and
fossil ammonites. (These are not...
-
smaller than 5
centimeters (2.0 inches) in diameter. The s**** is
always planispirally coiled,
unlike those of
Mesozoic ammonites in
which some are trochoidal...
-
epoch of the
early Silurian. The
earliest of
these were microscopic,
planispirally coiled, and evolute;
later forms evolved a
diversity of
shapes including...
-
Ismailia is a
genus of
foraminifera with an agglutinated,
planispirally coiled, semi-involute s****,
known from the
Egyptian Sinai, that
lived during...
-
families the s**** are not
helical in
their coiling, but
instead are
planispiral, flat-coiled. In
these s****, the
spire does not have a
raised point...
