Description of Ammonia
Test free, biconvex, low trochospiral coil of 3-4 turns, sutures are slightly curved and thickened. The wall is calcareous, finely perforated, with irregular granules along the sutures and over the umbilical region. The umbilicus region is depressed, the umbilicus has open fissures and a plug in younger organisms but this breaks into pillars in older cells. Widespread and extending into the Miocene
