Cambrian Hyolitha of Siberian, Baltican and Avalonian aspect in east Laurentian North America: taxonomy and palaeobiogeography

Abstract

Malinky, J.M. & Geyer, G., 6 March 2019. Cambrian Hyolitha of Siberian, Baltican and Avalonian aspect in east Laurentian North America: taxonomy and palaeobiogeography. Alcheringa 43, 171–203. ISSN 0311-5518.

Newly identified hyoliths from early Cambrian ‘Small Shelly Fossil’ assemblages in New York State and Quebec extend the geographical ranges of hyolith taxa, otherwise known only from Baltica and Siberia, into eastern Laurentian North America, and in some cases, are accompanied by significant stratigraphical range extensions. The newly recognized taxa from this region include the hyolithids Hexitheca washingtonensis sp. nov., Aimitus sp., A. sp. cf. A. communis, Anabaricornus sp., Similotheca americana, Grantitheca glenisteri, and the orthothecids Decoritheca sp., Contitheca sp., two species of Holmitheca, and two hyolith species that can not be confidently assigned to an order at this time. Early Cambrian limestone clasts within the Lower Ordovician of Quebec have produced the hyolithids Similotheca americana and Nevadotheca princeps. The occurrences of Aimitus, Anabaricornus, and Holmitheca provide a palaeobiogeographical link with hyolith assemblages in Siberia, and Hexitheca to Baltica. Contitheca not only is known from these areas, but also has been found in west Laurentia, Morocco, Korea and Antarctica. A review of previously named species demonstrates that none of their type materials can be confidently referred to genus or species level because of poor preservation.

John M. Malinky [[email protected]], Department of Physical Science, San Diego City College, 1313 Park Boulevard, San Diego, CA 92101, USA; Gerd Geyer* [[email protected]], Institut für Geographie und Geologie, Bayerische Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.

Key words:

• Hyolitha
• Cambrian
• Laurentia
• North America
• palaeobiogeography.

Acknowledgements

We are grateful to K. Hollis, J. Thompson, M. Florence, D. Levin, A. Telford and W. Brindle for access to specimens and other assistance at the US National Museum of Natural History, Smithsonian Institution, and T. Waller and F. Marsh, also of the Smithsonian Institution, for their assistance in photographing specimens. J. Dougherty, Geological Survey of Canada, was most generous in the lending of specimens of Similotheca americana and in providing information regarding localities. C.R. Ides, N. Tañon, and N. Oliver from San Diego City College, assisted in photographing specimens and with other logistical aspects at the USNM. D. Peter, Hitachi Data Systems, assisted with various technical aspects of manuscript preparation and proof-reading several versions of this manuscript. Further thanks go to J.S. Peel (Uppsala University) and N. Novozilova (A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Novosibirsk) provided comprehensive reviews and to the editors of Alcheringa whose critical remarks helped to significantly improve the manuscript.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The contribution of GG to this article was made possible by research grant GE 549/22-1 of the Deutsche Forschungsgemeinschaft (DFG)