''Tiltoniceras'' is an extinct genus of cephalopod belonging to the family

Hildoceratidae Hildoceratidae is a family of ammonoid cephalopods from the Lower Jurassic, lower Pliensbachian (''Jamesoni'' zone) to lower Bajocian (maybe even upper Bajocian) substages, generally with strongly ribbed, involute shells. They are combined with ...

. These

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s existed in the Jurassic period, from upper Pliensbachian age, Spinatum zone until lower Toarcian, Tenuicostatum zone in what is now Europe, North America and Asian part of Russia.

Description

Moderately involute to very involute shells, strongly keeled without sulci. They are compressed with rounded umbilical edge and nearly flat whorl sides. Ribs can be from strong, through fine, striate to smooth. They are gently sigmoidal to straight and on the venter they are strongly projected forward.

References

External links

Pliensbachian life Toarcian life Early Jurassic ammonites of Europe Ammonites of Europe Ammonites of Asia Ammonites of North America Hildoceratidae Ammonitida genera {{Ammonitina-stub