Tornoceratina is one of two suborders included in the Goniatitida, characterized by generally involute, subdiscoidal shells and by sutures in which the ventral ones are undivided.

Tornoceratina
Temporal range: Middle Devonian–Middle Permian
The prionoceratid Imitoceras rotatorium. Early Carboniferous, Rockford Limestone, Rockford, Illinois.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Goniatitida
Suborder: Tornoceratina
Wedekind, 1914
Superfamilies

Sutural lobes increase in number during the course of life of the individual, typically developed from the internal and external saddles. The siphuncle is prochoanitic, with septal necks projecting forward.

Derivation is from the Anarcestida in the middle Devonian.

References

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  • Miller, Furnish, and Schindewolf, 1957. Paleozoic Ammonoidea. Treastise on Invertebrate Paleontology, Part L. Geological Society of America.
  • Tornoceratina in Goniat on line, Mar. 5, 2015
  • The Paleobiology Database Oct.1, 2007