The coiled, flat, chambered fossil layer of an extinct cephalopod mollusk that has been abundant in the Cretaceous Period.
An explosive prepared from ammonium nitrate; amatol
any one of an extinct number of cephalopods associated with subfamily Ammonoidea; a fossil shell of such an animal
the fossil cephalopod layer regarding the nautilus. There are many genera and types, and all sorts of tend to be extinct, the standard types having been around only inside Mesozoic age, when they were exceedingly numerous. They change from the nautili in having the margins of septa really lobed or plaited, therefore the siphuncle dorsal. Also called serpent stone, snake rock, and cornu Ammonis.
among the fossil shells of an extensive genus (Ammonites) of extinct cephalopodous mollusks (cuttle-fishes), associated with the family members Ammonitidæ, coiled in a plane spiral, and chambered within such as the shell of current nautilus, to which the ammonites were allied.
A name placed on particular explosive materials, branded by Favier, containing ammonium nitrate along with other substances, chiefly nitro- or dinitro-naphthalene.
one of several coiled chambered fossil shells of extinct mollusks