Alocolytoceratinae


Alocolytoceratinae is a subfamily of lytoceratids that comprises genera characterized by many deep constrictions in the shell resulting in capricorn-like ornamention, especially in the middle whorls, but becoming smooth and more involute in the outer whorls. Saddle endings in the suture tend to be phylloid,.
Alcolytocerainae includes Alocolytoceras, Lobolytoceras, Pachylytocras, and Pleurolytoceras, which are mostly from the Toarcian. One genus, Pachylotoceras, extends into the lower Bajocian.