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This ammonite coils like a gastropod, rather like the Upper Cretaceous Didymoceras shown in the Pierre Shale section of this website. Note though, that it coils in the opposite direction from most gastropods. This is typical of this particular species, though in other ammonites of this shape, there is more of a 50-50 division between the different directions of coiling. In some earlier references, the subgenus is given as Plesioturrilites. Here, I am taking the latest (1996) Treatise on Invertebrate Paleontology, Part L, Mollusca 4, Vol. 4 as a reference. The height is only 1.4 cm.
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