Abstract
An unusually rich and diverse suite of virgianid brachiopods, hitherto poorly known, is systematically described here for the first time from the Ordovician–Silurian boundary interval (late Katian – Aeronian) of North Greenland. The Late Ordovician virgianids comprise typical taxa of the warm-water Tcherskidium fauna (e.g. Tcherskidium tenuicostatum, Proconchidium schleyi, Holorhynchus giganteus and Deloprosopus dawesi sp. nov.). Among the early Silurian taxa, Virgiana hursti sp. nov. occurs as abundant shell beds, similar to other congeneric species in Laurentia, but has somewhat larger internal skeletal structures, albeit not as extravagantly developed as in the late Katian virgianids; Borealoides balderi gen. et sp. nov. shows extreme thickening of the shell wall and internal structures, approaching the extravagant calcification of Katian virgianids. The highly distinctive mid-Aeronian stricklandioid brachiopod genus, Kulumbella, characterized by a shell with criss-cross (divaricate) ribbing, also occurs in North Greenland, represented by K. heimdali sp. nov., which has the largest and most strongly biconvex shells for the genus. Palaeogeographically, the Late Ordovician virgianid fauna of Laurentia was highly distinct, confined to the low–mid tropical latitudes north of the palaeoequator. In comparison, the early Silurian (Rhuddanian) Virgiana and some related taxa in Laurentia spanned the tropics of both hemispheres, forming extensive shell beds in carbonate basins, although Borealis and Borealoides gen. nov. remained confined largely to the northern hemisphere, suggesting a certain level of provincialism extending into the earliest Silurian. A palaeoecological preference for warm-water carbonate settings would explain the unusual abundance and richness of the virgianid faunas in North Greenland.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | e1544 |
| Tidsskrift | Papers in Palaeontology |
| Vol/bind | 10 |
| Udgave nummer | 1 |
| Antal sider | 42 |
| ISSN | 2056-2802 |
| DOI | |
| Status | Udgivet - 2024 |
Bibliografisk note
Funding Information:This is a much revamped study based partly on an earlier unfinished manuscript by PMS and J.M. Hurst in the 1980s. J.M. Hurst also collected a significant part of the North Greenland brachiopod material used in this study. We particularly thank Peter Dawes (GEUS), who collected some of the earliest material presented here, for performing, together with Simun D. Olsen, Stig A.S. Pedersen and Jon R. Ineson (GEUS) together with John Peel (Uppsala), the challenging tasks of retrieving locality data by looking through old archives, field notes and maps compiled before the age of the GPS in order to assign approximate coordinates to the oldest GGU localities collected. The Natural History Museum of Denmark provided access to the fossil material from North Greenland. The 2006 field work in North Greenland by three of the authors (JJ, DATH and CMØR) was funded by the Danish Natural Science Research Council (DATH), Natural Sciences and Engineering Research Council of Canada (JJ) and the University of Western Ontario (JJ). CMØR also acknowledges the Crown Prince Frederik Fund for funding his participation in the 2009 expedition to Kronprins Christian Land. DATH acknowledges support from the Leverhulme Trust (UK). Critical and constructive comments from journal reviewers L.E. Popov and J. Colmenar, and from the Editor L. Cherns, greatly improved this paper.
Funding Information:
This is a much revamped study based partly on an earlier unfinished manuscript by PMS and J.M. Hurst in the 1980s. J.M. Hurst also collected a significant part of the North Greenland brachiopod material used in this study. We particularly thank Peter Dawes (GEUS), who collected some of the earliest material presented here, for performing, together with Simun D. Olsen, Stig A.S. Pedersen and Jon R. Ineson (GEUS) together with John Peel (Uppsala), the challenging tasks of retrieving locality data by looking through old archives, field notes and maps compiled before the age of the GPS in order to assign approximate coordinates to the oldest GGU localities collected. The Natural History Museum of Denmark provided access to the fossil material from North Greenland. The 2006 field work in North Greenland by three of the authors (JJ, DATH and CMØR) was funded by the Danish Natural Science Research Council (DATH), Natural Sciences and Engineering Research Council of Canada (JJ) and the University of Western Ontario (JJ). CMØR also acknowledges the Crown Prince Frederik Fund for funding his participation in the 2009 expedition to Kronprins Christian Land. DATH acknowledges support from the Leverhulme Trust (UK). Critical and constructive comments from journal reviewers L.E. Popov and J. Colmenar, and from the Editor L. Cherns, greatly improved this paper.
Publisher Copyright:
© 2024 The Authors. Papers in Palaeontology published by John Wiley & Sons Ltd on behalf of The Palaeontological Association.