Choristoceratoidea

Choristoceratoidea
Temporal range:
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ceratitida
Superfamily:
Hyatt, 1900
Families
  • Choristoceratidae
  • Cochloceratidae
  • Rhabdoceratidae

Choristoceratoidea, formerly Choristocerataceae, is a superfamily of Late Triassic ceratitid ammonites. They can be characterized by their simple, four-lobed suture lines and unusual heteromorph shell shapes, which can resemble straight rods or twisting cones rather than the flat coils typical of other ammonites. The shells are usually small (less than 3 cm long) and ornamented with prominent ribbing.[1][2]

References

  1. ^ Shevyrev, A. A. (2005). "Heteromorph Ammonoids of the Triassic: A Review" (PDF). Paleontological Journal. 39 (supp5): S614 – S628.
  2. ^ Tozer, E. T. (August 1971). "Triassic Time and Ammonoids: Problems and Proposals". Canadian Journal of Earth Sciences. 8 (8): 989–1031. Bibcode:1971CaJES...8..989T. doi:10.1139/e71-088.