''Aulacosphinctes'' is an extinct genus of

ammonoid Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

cephalopod that lived during the Late

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

and had a widespread distribution. The shell is compressed, covered by strong, distinct, widely bifurcating ribs, some simple, none with tubercles; the venter marked by a deep and persistent groove; lappets rather long. Based on the style of ribbing ''Aulacosphinctes'' is included in the Himalayitinae, but could be placed in the Beriasellinae. ''Aulacosphinctes'' has been found in the Upper Jurassic (Tithonian) sediments in Algeria, east Africa, India, South America, and possibly California. Related genera include ''Hemisphincites'', ''Dickersonia'', ''Durangites'', and ''Himalyites''.

References

Bibliography

* Ammonitida genera Perisphinctoidea Jurassic ammonites Ammonites of South America Jurassic Argentina Jurassic Chile Jurassic Peru Tithonian life {{Ammonitina-stub