Shloenbachiidae is a family of hoplitacean

Hoplitaceae

Hoplitaceae is a superfamily of mostly Upper Cretaceous ammonites comprising families united by a similar suture pattern with multiple similar elements that tend to decrease in size going toward the umbilicus, at the inner edge of any whorl, and which are typically in a straight line...

 ammonoid cephalopds mostly from the lower Upper Cretaceous, (uU Albian - Cenomanian).

Shloenbachiidae can be recognized by their usually keel bearing, irregularly ribbed and tuberculate shells that vary from evolute to rather involute and compressed to inflated. Tubercles are concentrated on the umbilical and ventrolateral shoulders.

The suture, similar in all members, is ammonitic; raggedy with spikey subdivided lobes and irregularly subdivided saddles.

The Schloenbachiida first appeared near the end of the Albian, beginning with Schloenbachia

Schloenbachia

Schloenbachia is an ammonoid cephalopod genus from the Cenomanian stage of the Upper Cretaceous, and type for the Schloenbachiidae, a family within the ammonitid Hoplitaceae....

, derived from the hoplitid

Hoplitidae

The Hoplitidae is a family of Cretaceous ammonites that lived during the middle of the period from the late Aptian to the Cenomanian. They are part of the superfamily Hoplitaceae....

 genus Pleurohoplites or perhaps Lepthoplites, just before the beginning of the Late Cretaceous.

References

• Arkell, et al, 1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol. Soc. of America and Univ. Kansas Press.

Category: Ammonites
Category:Ammonitida