''Sirenites'' is a genus of

ammonoid Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

cephalopods from the Upper Triassic included in the Ceratitida, and type for the trachyceratid subfamily Sirenitinae. ''Sirenites'' has a compressed shell with distinct furrow running along the outer rim. Sides of the whorls are flattened to convex and covered with sigmoidal ribs that split on tubercles near the outer shoulder. there are two rows of tubercles on whorl sides and one on the inner, or umbilicle, shoulder. Although ''Sirenites'' is a ceratitid ammonoid, it suture is ammonitic.

References

Arkell, et al., Mesozoic Ammonoidea,

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part L, Mollusca 4, Geological Society of America. 1957. Trachyceratidae Triassic ammonites Ceratitida genera Triassic animals of Asia {{Ceratitida-stub