at least three other families of heteromorphs, the Baculitidae, Turrilitidae, and Scaphitidae. The lineage that gave rise to the helical Turrilitidae, for example, had a shell that initially grew as a helix before straightening out; the Turrilitidae thus appear to have been derived from neotenic Hamites that retained the helically-coiled juvenile morphology of Hamites into adulthood. See also Baculites Scaphites Turrilites References External links Gault Clay Ammonites, featuring Hamites and other Hamitidae Reconstructions of Hamites and related genera Ammonitida genera Turrilitoidea Cretaceous ammonites Ammonites of Australia Aptian genus first appearances Albian genera Cenomanian genus extinctions