Rare stromatoporoids from the Lower Devonian (Emsian) of Nevada, and their biostratigraphic and paleobiogeographic significance

• Published in: Journal of Paleontology
• Main Author: Stock, Carl W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2022
• Subjects: Arctic; Canada; Ellesmere Island
• Online Access: http://dx.doi.org/10.1017/jpa.2022.18; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002233602200018X

Abstract Two previously known species of stromatoporoids are reported from Nevada: Stromatoporella perannulata , from the Bartine Member of the McColley Canyon Formation (middle Emsian); and Stictostroma moosense , from the Oxyoke Canyon Sandstone (uppermost Emsian). A new species, Syringodictyon nevadense n. sp., is described from the Coils Creek Member of the McColley Canyon Formation (upper Emsian). Stromatoporella perannulata also occurs in Emsian-age strata on Ellesmere Island, arctic Canada, and in strata of Emsian and/or Eifelian age in Ontario, New York, Ohio, and Kentucky. Outside Nevada, Syringodictyon is confined to the Emsian of Ellesmere Island, and Emsian/Eifelian of Ontario and New York. Stictostroma moosense is known from only the Emsian/Eifelian of Ontario. It is concluded that the three Nevada specimens are Emsian in age. This implies that in other localities where two of the species, S . perannulata and S . moosense , occur in strata where the placement of the Emsian-Eifelian boundary is in question, it might be higher than previously thought. The presence of the two species, plus Syringodictyon , in both the Old World Realm (Nevada, arctic Canada) and the Eastern Americas Realm (Ontario, New York, Ohio, Kentucky), infers a selective marine connection between the two realms that was not available to other taxa. The breach in the inter-realm barrier most likely occurred as a shallow seaway across the Canadian Shield. UUID: http://zoobank.org/e73023c6-88ca-4b4d-9b01-f74a75b99c43