serpenticonen.
/səːˈpɛntɪkəʊn/ Palaeontology.
An ammonoid in which the whorls are slender and overlap very little, so that the shell resembles a coiled snake.
ΚΠ
1923 H. H. Swinnerton Outl. Palæontol. x. 214 The forms assumed by these derivatives [of cadicones] were determined mainly by modification of the whorl shape in two directions. In the one the venter and dorsum became arched; the outer consequently embraced the inner whorls and the umbilicus became narrower and even disappeared. The shell thus produced was globose in shape and is described as a sphærocone... In the other modification the whorl increased in height..; the effect of this was to produce a shell with a widely open umbilicus and having the appearance of a coiled snake. The descriptive term serpenticone is therefore applied to this type of shell.
1970 R. M. Black Elements Palaeontol. viii. 87 Dactylioceras..has an evolute shell with a wide, shallow umbilicus; the whorl section is oval. It is a typical serpenticone.
This entry has not yet been fully updated (first published 1986; most recently modified version published online June 2018).
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n.1923