Key morphological features: Shells of this group are large, ranging from involute to evolute. Strong ribbing sometimes with extra ornamentation. Suture lines tend to be smaller, narrow, and asymmetric.
MOBILITY: Mobile (swim)
FEEDING MODE: Predator
Wright, C. W., 1996. Ammonoidea, in Kaesler, R. L., ed., Treatise on Invertebrate Paleontology, Part L, Mollusca 4 Revised, Volume 4. The University of Kansas and Geological Society of America. 362 pp.