- An ammonoid fossil, especially one of a later type found chiefly in the Jurassic and Cretaceous periods, typically with intricately frilled suture lines. Compare with ceratite and goniatite.
More example sentences
- Typified by ammonoids of the order Ammonitida
- Argonauta shares other characteristics with some Jurassic and Cretaceous ammonites, namely multicuspid rachidial tooth on the radula.
- The fossil content consists of ammonites, belemnites, brachiopods, echinoderms, bivalves, crinoids, gastropods, ostracodes and benthic foraminifers.
- A feature of especial interest is that, while the youngest Triassic ammonites are quite rare, the oldest Jurassic ammonites are extremely abundant, entering the succession in a veritable flood.
mid 18th century: from modern Latin ammonites, from medieval Latin cornu Ammonis 'horn of Ammon', from the fossil's resemblance to the ram's horn associated with Jupiter Ammon (see ammoniacal).
More definitions of ammoniteDefinition of ammonite in:
- The US English dictionary