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]
Choristoceratoidea Temporal range:
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | †Ammonoidea |
Order: | †Ceratitida |
Superfamily: | †Choristoceratoidea Hyatt, 1900 |
Families | |
References
edit- ^ Shevyrev, A. A. (2005). "Heteromorph Ammonoids of the Triassic: A Review" (PDF). Paleontological Journal. 39 (supp5): S614–S628.
- ^ 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.