Traits taxon details
original description
(of Orygoceras (Ibicicornu) arcuatum Dall, 1924 †) Dall, W. H. (1924). Discovery of a Balkan fresh-water fauna in the Idaho Formation of Snake River Valley, Idaho. <em>United States Geological Survey Professional Paper.</em> 132-G: 109-115., available online at https://doi.org/10.3133/pp132G page(s): 113, pl. 26, fig. 5 [details] Available for editors 
original description
(of Orygoceras tricarinatum Yen, 1944 †) Yen, T.-C. (1944). Notes on Fresh-Water Mollusks of Idaho Formation at Hammett, Idaho. <em>Journal of Paleontology.</em> 18(1): 101-108. page(s): 106, fig. 3 [details] Available for editors 
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