Anasirenites
 Anasirenites is an extinct ammonoid cephalopod genus within the family Trachyceratidae which is part of the ceratitid superfamily Clydonitaceae; sometimes considered a subgenus of Sirenites. Anasirenites is characterized by a ventral furrow bordered on either side by a continuous keel. The shell as for Sirenites is compressed with whorls flattened-convex on the sides. Sigmoidal ribs on the flanks bifurcate near the ventro-lateral shoulder on tubercles and project sharply adorally.