Definitions for "Ammonite"
A fossil cephalopod shell related to the nautilus. There are many genera and species, and all are extinct, the typical forms having existed only in the Mesozoic age, when they were exceedingly numerous. They differ from the nautili in having the margins of the septa very much lobed or plaited, and the siphuncle dorsal. Also called serpent stone, snake stone, and cornu Ammonis.
Ammonites had a spiral shell similar to the closely related Nautilus. They are also related to squid and octopus. Their name comes from the Egyptian god Ammon (Amun) who is sometimes associated with ram horns similar in shape to ammonites. They appeared around 400 million years ago and evolved very quickly, making them useful for dating rocks. Ammonites became extinct at the same time as the dinosaurs, 65 million years ago.
Sea faring creatures from the Cretaceous period, ammonites were mollusks that built a chambered shell in which they would pump air into the empty chambers which allowed them to float at different levels of the ocean.
Nicola Griffith's first novel, Ammonite was published in 1993, with ISBN 0-345-37891-1. It won both the Lambda Literary Award for LGBT (lesbian, gay, bisexual, transgendered) fiction, and the James Tiptree, Jr. Award for science fiction or fantasy that explores or expands our understanding of gender.