Two exceptionally preserved biotas from North Dakota reveal cryptic Ordovician shelf ecologies.

ABSTRACT: The Ordovician saw one of the greatest evolutionary radiations in the Earth's history, precipitating the assembly of modern animal-dominated ecologies in the aftermath of the Cambrian Explosion. However, Ordovician nonmineralized faunas are rare and mostly sample ecologically marginal settings. We describe small carbonaceous fossils (SCFs), including semiarticulated elements preserving submicrometric detail, from epicratonic deposits of the Deadwood and Winnipeg formations (ND). The Osterberg SCFs, associated with biostratigraphically informative conodonts and graptolites, record two successive biotas of Cambrian-Tremadocian (the "lower Osterberg" biota) and Darriwilian (the "upper Osterberg" biota) ages, demonstrating a long-term persistence of high-quality, Burgess Shale-type microfossil

SUBMITTER: Mussini G 

PROVIDER: S-EPMC12646318 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature